Taxonomic revision and molecular phylogeny of Pisa (Decapoda: Majoidea: Epialtidae), including the description of a new genus of Pisinae

INTRODUCTION

Pisa Leach, 1814Leach W.E. 1814. Crustaceology. In: Brewster D. (ed), The Edinburgh Encyclopaedia. Balfour, Edinburgh 7: 385-437. https://www.biodiversitylibrary.org/page/37187640 currently comprises eight good species (WoRMS Editorial Board 2023, accessed 2023-06-23WoRMS Editorial Board (2023). World Register of Marine Species. Available from https://www.marinespecies.org at VLIZ. Accessed 2023-06-23. doi: 10.14284/170 https://www.marinespecies.org/aphia.php?p=taxdetail-s&id=106912 ): P. armata (Latreille, 1803Latreille P.A. 1803. Histoire naturelle, générale et particulière des crustacés et des insectes. Paris, F. Dufart 6: 1-391, 12 pls. https://doi.org/10.5962/bhl.title.15764 https://www.biodiversitylibrary.org/page/24882091 ), P. calva Forest and Guinot, 1966Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124., P. carinimana Miers, 1879Miers E.J. 1879. Descriptions of new or little-known species of Majoid Crustacea (Oxyrhyncha) in the collection of the British Museum. Ann. Mag. Nat. Hist. 4: 1-28. https://www.biodiversitylibrary.org/part/63135 https://doi.org/10.1080/00222937908679780 , P. hirticornis (Herbst, 1804Herbst J.F.W. 1804. Versuch einer Naturgeschichte der Krabben und Krebse, nebst einer systematischen Beschreibung ihrer verschiedenen Arten. Berlin und Stralsund, Gottlieb, August und Lange. 3(4): 1-49, pls. LIX-LXII. https://doi.org/10.5962/bhl.title.64679 ), P. muscosa (Linnaeus, 1758Linnaeus C. 1758. Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata [10th revised edition], 1: 824 pp. Laurentius Salvius: Holmiae. https://doi.org/10.5962/bhl.title.542 https://www.biodiversitylibrary.org/bibliography/559 ), P. nodipes Leach, 1815, P. sanctaehelenae Chace, 1966Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 and P. tetraodon (Pennant, 1777Pennant T. 1777. British Zoology, vol. IV. Crustacea. Mollusca. Testacea. London: I-viii, 1-154, pl. 1-93. https://www.biodiversitylibrary.org/item/127011#page/5/mode/1up ). The genus is distributed in the eastern Atlantic Ocean and in the Mediterranean Sea.

Pisa was established by Leach (1814: 431)Leach W.E. 1814. Crustaceology. In: Brewster D. (ed), The Edinburgh Encyclopaedia. Balfour, Edinburgh 7: 385-437. https://www.biodiversitylibrary.org/page/37187640 for Cancer biaculeatus Montagu, 1813Montagu G. 1813. Descriptions of several new or rare animals, principally marine, discovered on the South coast of Devonshire. Trans. Linn. Soc. Lond. 11: 1-26, pls. 1-5. https://doi.org/10.1111/j.1096-3642.1813.tb00035.x , a junior synonym of Maja armata Latreille, 1803Latreille P.A. 1803. Histoire naturelle, générale et particulière des crustacés et des insectes. Paris, F. Dufart 6: 1-391, 12 pls. https://doi.org/10.5962/bhl.title.15764 https://www.biodiversitylibrary.org/page/24882091 . Later, Leach (1815: 50)Leach W.E. 1815. The Zoological Miscellany; Being Descriptions of New, or Interesting Animals. R.P. Nodder, London 2: 1-154, pls: 61-120. https://www.biodiversitylibrary.org/page/28685302 described and added a new species, Pisa nodipes, to Pisa. H. Milne Edwards (1834Milne Edwards H. 1834. Histoire Naturelle des Crustacés, Comprenant l’Anatomie, la Physiologie et la Classification de ces Animaux. Libraire Encyclopédique Roret, Paris; I: 1-468. http://www.biodiversitylibrary.org/bibliography/16170#/summary https://doi.org/10.5962/bhl.title.16170 ) placed these two species under Pisa together with P. tetraodon (Pennant 177: 6Pennant T. 1777. British Zoology, vol. IV. Crustacea. Mollusca. Testacea. London: I-viii, 1-154, pl. 1-93. https://www.biodiversitylibrary.org/item/127011#page/5/mode/1up ), P. armata, P. corallina (currently considered a junior subjective synonym of P. hirticornis), P. gibsii Leach, 1815Leach W.E. 1815. The Zoological Miscellany; Being Descriptions of New, or Interesting Animals. R.P. Nodder, London 2: 1-154, pls: 61-120. https://www.biodiversitylibrary.org/page/28685302 (currently a junior subjective synonym of P. armata) and P. styx (described by Herbst 1803Herbst J.F.W. 1803. Versuch einer Naturgeschichte der Krabben und Krebse, nebst einer systematischen Beschreibung ihrer verschiedenen Arten. Berlin und Stralsund, Gottlieb, August und Lange. 3(3): 1-54, pls. LV-LVIII. https://doi.org/10.5962/bhl.title.64679 as Cancer styx, but currently placed in the genus Tylocarcinus Miers, 1879Miers E.J. 1879. Descriptions of new or little-known species of Majoid Crustacea (Oxyrhyncha) in the collection of the British Museum. Ann. Mag. Nat. Hist. 4: 1-28. https://www.biodiversitylibrary.org/part/63135 https://doi.org/10.1080/00222937908679780 ). H. Milne Edwards also mentioned that P. nodipes seemed very close to P. armata and that Cancer hirticornis also belonged to the genus Pisa. However, the first species described belonging to Pisa was Pisa muscosa Linnaeus, 1758Linnaeus C. 1758. Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata [10th revised edition], 1: 824 pp. Laurentius Salvius: Holmiae. https://doi.org/10.5962/bhl.title.542 https://www.biodiversitylibrary.org/bibliography/559 (Linnaeus 1758: 628Linnaeus C. 1758. Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata [10th revised edition], 1: 824 pp. Laurentius Salvius: Holmiae. https://doi.org/10.5962/bhl.title.542 https://www.biodiversitylibrary.org/bibliography/559 , as Cancer muscosus).

Risso (1816: 45)Risso A. 1816. Histoire Naturelle des Crustacés des Environs de Nice. Librairie GrecqueLatine-Allemande, Paris. 175 pp., 3 pls. https://doi.org/10.5962/bhl.title.8992 described Maia corallina, Lucas (1840: 137, 138)Lucas P.H. 1840. Histoire naturelle des Crustacés: des arachnides et des myriapodes. Ed. Duménil, Paris, 1-600. and, more recently, other authors (e.g. Zariquiey Álvarez 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf , d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.), considered it a good species as Pisa corallina (Risso, 1816Risso A. 1816. Histoire Naturelle des Crustacés des Environs de Nice. Librairie GrecqueLatine-Allemande, Paris. 175 pp., 3 pls. https://doi.org/10.5962/bhl.title.8992 ). Currently, it is considered a synonym of P. hirticornis (Herbst, 1804Herbst J.F.W. 1804. Versuch einer Naturgeschichte der Krabben und Krebse, nebst einer systematischen Beschreibung ihrer verschiedenen Arten. Berlin und Stralsund, Gottlieb, August und Lange. 3(4): 1-49, pls. LIX-LXII. https://doi.org/10.5962/bhl.title.64679 ) according to Sakai (1999)Sakai K. 1999. J. F. W. Herbst-Collection of Decapod Crustacea of the Berlin Zoological Museum, with remarks on certain species. Naturalists, Publications of Tokushima Biological Laboratory, Shikoku University 6: 1-45, pls 1-21..

Zariquiey Álvarez (1959)Zariquiey Álvarez R. 1959. Crustáceos Decápodos de la región de Cadaqués. II Parte. Misc. Zool. 1(2): 1-7. https://decapoda.nhm.org/pdfs/30246/30246.pdf clarified the taxonomic position of P. muscosa in relation to P. tetraodon and P. hirticornis, using morphological characteristics, and Forest (1966)Forest J. 1966. Campagnes du “Professeur Lacaze-Duthiers” aux Baléares : Juin 1953 et août 1954. Crustacés décapodes. Vie et Milieu, série B, Océanographie 16 (1B) [for 1965]: 325-413. https://decapoda.nhm.org/pdfs/15928/15928.pdf also gave a precise redescription of the three Pisa of the tetraodon complex.

Ng et al. (2008)Ng P.K.L., Guinot D., Davie P.F. 2008. Systema Brachyurorum: Part 1. An Annotated checklist of extant Brachyuran crabs of the world. Raffles Bull. Zool., Suppl. ser. 17: 1-296. https://lkcnhm.nus.edu.sg/wp-content/uploads/sites/10/app/uploads/2017/04/s17rbz.pdf considered a ninth species: Pisa lanata (Lamarck, 1801: 151)Lamarck J.B. 1801. Système des animaux sans vertèbres, ou tableau général des classes, des ordres et des genres de ces animaux; Présentant leurs caractères essentiels et leur distribution, d’après la considération de leurs rapports naturels et de leur organisation, et suivant l’arrangement établi dans les galeries du Muséum d’Histoire Naturelle, parmi leurs dépouilles conservées; Précédé du discours d’ouverture du Cours de Zoologie, donné dans le Muséum National d’Histoire Naturelle l’an 8 de la République. Published by the author and Deterville, Paris: viii + 432 pp. https://doi.org/10.5962/bhl.title.14255 , described as Arctopsis lanata with an extremely concise definition, but it is considered as a synonym of P. armata according to the WoRMS Editorial Board (2023)WoRMS Editorial Board (2023). World Register of Marine Species. Available from https://www.marinespecies.org at VLIZ. Accessed 2023-06-23. doi: 10.14284/170 https://www.marinespecies.org/aphia.php?p=taxdetail-s&id=106912 (see Remarks of Pisa armata).

The last three species described under the genus Pisa were P. carinimana by Miers (1879: 11-12)Miers E.J. 1879. Descriptions of new or little-known species of Majoid Crustacea (Oxyrhyncha) in the collection of the British Museum. Ann. Mag. Nat. Hist. 4: 1-28. https://www.biodiversitylibrary.org/part/63135 https://doi.org/10.1080/00222937908679780 , P. sanctaehelenae by Chace (1966: 651-654)Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 and P. calva by Forest and Guinot (1966: 99-104)Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124., mainly distributed in African Atlantic waters. The close relationship between these species has already been pointed out by d’Udekem d’Acoz (1999)d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.. Furthermore, they exibit some morphological features that put in doubt their generic placement. Consequently, this study is focused on the revision of Pisa species and allied genera, such as Lissa Leach, 1815Leach W.E. 1815. The Zoological Miscellany; Being Descriptions of New, or Interesting Animals. R.P. Nodder, London 2: 1-154, pls: 61-120. https://www.biodiversitylibrary.org/page/28685302 and Micropisa Stimpson, 1857Stimpson W. 1857. Prodromus descriptionis animalium evertebratorum, quae in Expeditione ad Oceanum Pacificum Septentrionalem, a Republica Federata missa, Cadwaladaro Ringgold et Johanne Rodgers Ducibus, observavit et descripsit W. Stimpson. Pars III. Crustacea Majoidea. Proc. Acad. Nat. Sci. Philadelphia 9: 216-221. https://doi.org/10.5962/bhl.title.51447 , based on a re-examination of their morphological characters according to the phylogenetic relationships revealed by molecular analyses of two mitochondrial genes.

Considering the present results of the reviewed genera and species, an illustrated key for the identification of eastern Atlantic and Mediterranean Pisinae Dana, 1851Dana J.D. 1851. Conspectus Crustaceorum quae in Orbis Terrarum circumnavigatione, Carolo 1775 Wilkes e classe Reipublicae Faederatae Duce, lexit et descripsit. Pars VI. Am. J. Sci. Arts Series 2: 268-274. is provided.

MATERIALS AND METHODS

Morphological study

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The specimens examined were accessed from several natural history and study collections: “Colección de Crustáceos Marinos del Centro Oceanográfico de Cádiz” (CRUST-IEOCD, IEO-CSIC), “Colecciones Biológicas Marinas de Referencia” (CBMR, ICM-CSIC), “Colección Zariquiey” (CBMR, ICM-CSIC), Crustacean Collection of the Naturalis Biodiversity Centre (NBC), “Museu de História Natural do Funchal” (MMF), and the private collections of J. E. García Raso, E. P. Lopes, A. M. Santos and J. A. Cuesta (all them deposited in CRUST-IEOCD). These specimens are indicated in the Results section under the respective species.

Other material examined for comparative purposes: Anamathia rissoana. SPAIN, Mediterranean, ♀ 36.4×27.5 mm, ICMD742/1991; Alicante, Cabo La Nao, ♂ 25.8×22.9 mm, 296-305 m, 38.49°N 0.479°E, 6 May 2003, ICMD001017. Apiomitrax bocagei. GUINEA-BISSAU, ♀ 27.8×26.1 mm, LANGABISS0211, stn 48, 63 m, 11.36°N17.09°W, 12 May 2011, IEOCD-LB0211/432-1; ♀ 33.6×31.1 mm, LANGABISS0211, stn 48, 63 m, 11.36°N17.09°W, 12 May 2011, IEOCD-LB0211/432-2; ♂ 40.6×37 mm, ♂ 39.1×34.9 mm, ♂ 31.7×31 mm, ♂ 30.2×28.1 mm, LANGABISS0211, stn 179, 26 m, 11.44°N17.07°W, 31 May 2011, IEOCD-LB0211/431. Micropisa ovata. CAPE VERDE, ♀ 4.8×5.0 mm, ♀ 7.4×7.5 mm, ♂ 7.0×7.3 mm, ♂ 3.5×3.8 mm, IEOCD-PISA/3039-1-2-3. Scyramathia hertwigi. IRELAND, Porcupine Bank, ♂ 41.1×41.1 mm, PORCUPINE13, stn 4, 492-493 m, 51.77°N 51.80°W, 5 Sep. 2013, IEOCD-PC13/1752; GUINEA-BISSAU, ovig ♀ 45.6×48.9 mm, LANGABISS0111, stn 203, 551 m, 10.01°N 17.11°W, 19 Apr. 2011, IEOCD-LB0111/404; ♂ 55×58.5 mm, BISSAU0811, stn 30, 550 m, 10.29°N 17.26°W, 28 Oct. 2008, IEOCD-GB0810/181; NAMIBIA, ♂ 29.6×32 mm, NAMIBIA0702, stn 58, 710-718 m, 27.527°S 14.51°E, 21 Feb. 2007, IEOCD-NB02/2444; ♂ 26.2×27.9 mm, NAMIBIA0702 stn 75, 502 m, 28.082°S 14.60°E, 24 Feb. 2007, IEOCD-NB02/2445.

Specimens of all species currently classified in Pisa, as well as individuals of Lissa chiragra (Fabricius, 1775Fabricius J.C. 1775. Systema Entomologiae, sistens Insectorum Classes, Ordines, Genera, Species, adjectis Sysnonymis, Locis, Descriptionibus, Observationibus. Kortii, Flensburgi et Lipsiae. 832 pp. https://doi.org/10.5962/bhl.title.36510 ), Micropisa ovata Stimpson, 1857Stimpson W. 1857. Prodromus descriptionis animalium evertebratorum, quae in Expeditione ad Oceanum Pacificum Septentrionalem, a Republica Federata missa, Cadwaladaro Ringgold et Johanne Rodgers Ducibus, observavit et descripsit W. Stimpson. Pars III. Crustacea Majoidea. Proc. Acad. Nat. Sci. Philadelphia 9: 216-221. https://doi.org/10.5962/bhl.title.51447 and other Pisinae were reviewed, measured and photographed. This review was undertaken after a morphological examination of the specimens and a thorough analysis of their original descriptions. The only exception was the case of P. sanctaehelenae, for which the morphological details were taken from the original species description. The holotype and paratypes of this species are deposited in the National Museum of Natural History, Smithsonian Institution. Unfortunately, obtaining a loan of this material was not possible because of COVID-19 restrictions.

The terminology used in the descriptions and comparisons follows Davie et al. (2015)Davie P.J., Guinot D. and Ng P.K. 2015. Anatomy and functional morphology of Brachyura. Treatise on Zoology-Anatomy, Taxonomy, Biology. The Crustacea, Volume 9 Part C (2 vols), 11-163. https://doi.org/10.1163/9789004190832_004 and is illustrated in Figure 1. Measurements and abbreviations used in the text and figures are: cl, maximum carapace length (without including the rostral spines as they break very easily) along the dorsal midline from the base of the rostral sinus to the posterior margin of the carapace; cw, maximum carapace width (including lateral spines) taken at its widest point, including lateral spines; G1, first gonopod; G2, second gonopod; hesp, hepatic spine; intsp, intercalated spine; pol, postorbital lobe; prl, pre-orbital lobe; P2-P5, pereopods 2 to 5 (P1 is the cheliped); soe, supraorbital margin. Other abbreviations used are indet, indeterminate; juv, juvenile; ovig, ovigerous, stn, station; ♂, male; ♀, female. For P. sanctaehelenae, the measurements were taken from Chace (1966)Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 .

Fig. 1.  Schematic representation of an adult specimen of Pisinae. A, dorsal view of the carapace, B, details of the orbital and hepatic regions, and C, anteroventral view of the carapace (modified from Chace (1966)Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 and Forest and Guinot (1966)Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124.).

Molecular data

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Few published studies include DNA sequences of Pisa species. Windsor and Felder (2014)Windsor A.M., Felder, D.L. 2014. Molecular phylogenetics and taxonomic reanalysis of the family Mithracidae MacLeay (Decapoda: Brachyura: Majoidea). Invertebr. Syst. 28(2): 145-173. https://doi.org/10.1071/IS13011 provided sequences for the 12S, 16S, 18S and COI genes for a single specimen of P. tetraodon. Raupach et al. (2015)Raupach M.J., Barco A., Steinke D., et al. 2015. The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions. PLoS ONE 10: e0139421. https://doi.org/10.1371/journal.pone.0139421 gave two different COI sequences for P. armata, and Mugnai et al. (2023)Mugnai F., Costantini F., Chenuil A., et al. 2023. Be positive: customized reference databases and new, local barcodes balance false taxonomic assignments in metabarcoding studies. PeerJ, 11, e14616. https://peerj.com/articles/14616/ https://doi.org/10.7717/peerj.14616 provided two identical COI sequences for P. nodipes, although one is submitted under the name of P. armata. Additionally, there is a short (~400 bp) COI fragment submitted by Fernandez (unpublished) for P. tetraodon, and another COI sequence attributed to P. armata from Lombok Island (Indonesia) deposited by Ambariyanto et al. (unpublished). The latter identification is likely to be wrong, since its average genetic distance from other Pisa species, is at least 11.5%. In BOLD, excluding the sequences mined from GenBank, there is one COI sequence for P. armata (identified as P. nodipes) from the Algarve (Portugal) and nine COI sequences of P. carinimana marked as “early-release” and therefore not available for use in this study. DNA barcodes were obtained from nine species with a total of 37 and 30 new 16S and COI sequences, respectively, (see Table 2) in the present study.

Molecular data obtained and analysed in the present study support the species composition of the genus Pisa, including P. hirticornis (see Figs 2-4Figs 2, 3, 4); Pisa is a monophyletic group when it includes Lissa chiragra (as Pisa chiragra n. comb. in Figs 2-4Figs 2, 3, 4) and when P. carinimana (as Afropisa carinimana n. comb. in Figs 2-4Figs 2, 3, 4) is placed in a new genus. From this point forward, these changes will be implemented for the mentioned species.

Two distinct groups can be observed within Pisa, and this grouping is also supported by morphological evidence. One group includes P. armata, P. nodipes and P. chiragra n. comb., while the other group consists of P. muscosa, P. hirticornis and P. tetraodon. Furthermore, Afropisa carinimana n. comb. is phylogenetically closer to Micropisa Stimpson, 1857Stimpson W. 1857. Prodromus descriptionis animalium evertebratorum, quae in Expeditione ad Oceanum Pacificum Septentrionalem, a Republica Federata missa, Cadwaladaro Ringgold et Johanne Rodgers Ducibus, observavit et descripsit W. Stimpson. Pars III. Crustacea Majoidea. Proc. Acad. Nat. Sci. Philadelphia 9: 216-221. https://doi.org/10.5962/bhl.title.51447 than to Pisa (Figs 2-4Figs 2, 3, 4).

Fig. 2.  Phylogenetic relationships of Epialtidae species inferred from the combined maximum likelihood and Bayesian analysis of 16S rRNA. Tree topology was obtained from maximum likelihood analysis. Scale bar represents 0.09 substitutions per site. The bootstrap values for maximum likelihood and Bayesian analysis appear one after the other at each node, respectively. Apiomithrax violaceus sequence was used as outgroup.

Fig. 3.  Phylogenetic relationships of Epialtidae species inferred from the combined maximum likelihood and Bayesian analysis of COI. Tree topology was obtained from maximum likelihood analysis. Scale bar represents 0.09 substitutions per site. The bootstrap values for maximum likelihood and Bayesian analysis appear one after the other at each node, respectively. Apiomithrax violaceus sequence was used as outgroup.

Fig. 4.  Epialtidae species tree estimed according to a fully Bayesian multispecies coalescent method implemented in StarBEAST2 based on mitochondrial COI and 16S rRNA markers. Apiomithrax violaceus sequence was used as an outgroup.

SYSTEMATIC ACCOUNT

Diagnosis (Figs 5G-I, 6G-H). Carapace subpyriform, longer than wide, with regions well delimited. Rostral spines divergent from the base or close to it, in V-shape or U-shape. Orbital margin: supraorbital margin projected forward in a protruding angular lobe, intercalated spine or tooth between supraorbital margin and postocular process; flat plate-shaped postocular process (dorsal view). A strong spine on hepatic region behind postocular process. Laterobranchial margins with one to four spines. Basal antennal segment with distal outer spine visible from above (between the rostral spines and the supraorbital margin), and a distinct tooth or elongated bump just posterior to posterolateral angle of antennal basal segment.

Pterygostomian region with three or four tubercles along the lateral margin, decreasing in size posteriorly (Fig. 7A1).

Mesogastric region bulging and prominent, with one small anterior tubercle; cardiac region highly convex or swollen surrounded by a deep furrow, both without spines. Intestinal region with a median prominence, small spine or tubercle. Dorsal branchial regions with protuberances on each side: one or two small blunt epibranchial tubercles and one mesobranchial blunt spine or lobe.

Cheliped: merus with prominent tubercles on dorsal midline, with one large tubercle on the dorsal articulation with the carpus; propodus with well-defined ventral margin (resembling a keeled structure).

Male G1 slender, rather straight proximally, slightly curved subdistally, with broadened distal part. The outer distal side is pointed and shows a subdistal small finger-like process projecting inward (sometimes not visible), and the inner distal side is like a downward- or upward-curved projection or tongue (Fig. 7B, Forest and Guinot 1966: Figs 12-13Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124.; Chace 1966: Fig. 14g, hChace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 ).

Specimens of relatively small sizes.

Type species. Pisa carinimana Miers, 1879Miers E.J. 1879. Descriptions of new or little-known species of Majoid Crustacea (Oxyrhyncha) in the collection of the British Museum. Ann. Mag. Nat. Hist. 4: 1-28. https://www.biodiversitylibrary.org/part/63135 https://doi.org/10.1080/00222937908679780 , by present designation. Topotypic locality: Canary Islands. Holotype deposited in British Museum (according to Monod 1956Monod T. 1956. Hippidea et Brachyura ouest-africains. Mem. IFAN 45: 1-674, 884 Figs).

Other species included. P. sanctaehelenae Chace, 1966Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 and P. calva Forest and Guinot, 1966Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124..

Material examined. See below under the respective species within this new genus.

Etymology. The root “Afro” means African or native to Africa, referring to the main localities of the species within the new genus, and the ending “pisa” refers to the genus Pisa, where these species were originally classified. The genus name is feminine.

Remarks. Afropisa n. gen. mainly differs from Pisa by having a small and subpyriform carapace; rostral spines divergent from the base or close to it, in V-shape or U-shape (Figs 5G-I, 6G-H); pterygostomial region with three or four tubercles along the lateral margin, decreasing in size posteriorly (however, in some specimens of A. carinimana n. comb. only a pair of tubercles can be found in one of the pterygostomial areas) (Fig. 7A1); and male G1 with a small finger-like process projecting inward on the outer distal plate that is absent in the Pisa species (Figs 7B, 8A-E; Zariquiey Álvarez 1968, Figs 154 a-e, 156cZariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf ), which tend to have a more prominent, upward-directed external distal plate.

Micropisa can be easily differentiated from Afropisa n. gen., as well as from Pisa by the absence of the intercalated spine or lobe on the orbital margin (A. Milne-Edwards 1868: pl. 16, Fig. 1Milne-Edwards A. 1868. Observations sur la faune carcinologique des iles du Cap Vert. Nouv. Arch.Mus.Hist.Nat., Paris, IV : 49-68 ; pls XVI-XVIII. https://doi.org/10.5962/bhl.part.15909 ; Monod 1956: Fig. 669Monod T. 1956. Hippidea et Brachyura ouest-africains. Mem. IFAN 45: 1-674, 884 Figs). However, Micropisa shares the morphology of the male G1 with Afropisa n. gen. because of a small finger-like process projecting inward on the outer distal lobe (Monod 1956: Figs 679-681Monod T. 1956. Hippidea et Brachyura ouest-africains. Mem. IFAN 45: 1-674, 884 Figs). In addition, Monod (1956: 499)Monod T. 1956. Hippidea et Brachyura ouest-africains. Mem. IFAN 45: 1-674, 884 Figs, when comparing Micropisa with Pisa, mentioned that Stimpson (1857)Stimpson W. 1857. Prodromus descriptionis animalium evertebratorum, quae in Expeditione ad Oceanum Pacificum Septentrionalem, a Republica Federata missa, Cadwaladaro Ringgold et Johanne Rodgers Ducibus, observavit et descripsit W. Stimpson. Pars III. Crustacea Majoidea. Proc. Acad. Nat. Sci. Philadelphia 9: 216-221. https://doi.org/10.5962/bhl.title.51447 stated that “there was a generic difference also in the mxp 3, whose merus would be without a notch for the reception of the carpus in Micropisa and with a notch in Pisa (Figs 7A2,3); however, P. carinimana (which cannot be separated from the other Pisa) has no notch” (Fig. 7A1).

Pisa carinimana Miers, 1879: 11-12Miers E.J. 1879. Descriptions of new or little-known species of Majoid Crustacea (Oxyrhyncha) in the collection of the British Museum. Ann. Mag. Nat. Hist. 4: 1-28. https://www.biodiversitylibrary.org/part/63135 https://doi.org/10.1080/00222937908679780 (superseded combination).

Material examined. Portugal, Madeira, Bay of Funchal, ovig ♀ 5.3×5.6 mm, 28 Nov. 2013, MMF 42827. Spain, Canary Islands, Gran Canaria, Maspalomas, ovig ♀ 5.3×7.1 mm (cw × cl), ♀ 5.8×7.2 mm, CIRCAN2020, stn 21, 65-70 m, 27.71°N 15.55°W, 27 Nov. 2020, IEOCD-CIRCAN20/3017; Canary Islands, Lanzarote, La Lajita, ♀ 3.4×4.2 mm, ovig ♀ 4.9×5.7 mm, 2 ♂ 5×6.1 mm, 2.7×3.5 mm, CIRCAN2020, stn 55, 53-54 m, 28.15°N 14.16°W, 2 Dec. 2020, IEOCD-CIRCAN20/3018; Canary Islands, Fuerteventura, 9 Jul. 2012, IEOCD-PISA/291 (damaged); Málaga, Caleta de Vélez, ♂ 15.65×15.97 mm, 24-26 m, 36.74°N 4.071°W, 31 May 1978, IEOCD-PISA/3019; Málaga, Caleta de Vélez, ♂ 10.97×12.58 mm, ♂ 15.48×15.65 mm, ♀ 10.1×10.48 mm, 36.74°N 4.071°W, 1 Aug. 1979, IEOCD-PISA/3022; Málaga, Fuengirola, ♀ 10.08×12.42 mm, ♀ 12.74×12.26 mm, 26-31 m, 36.53°N 4.61°W, 14 Jul. 1976, IEOCD-PISA/3020; Málaga, Marbella, ♂ 9.03×10.81 mm, 33-44 m, 36.49°N 4.88°W, 21 Dec. 1978, IEOCD-PISA/3021; Málaga, Calahonda, ♀ 10.32×10.97 mm, ♂ 5.6×6.5 mm, 1-5 m, 36.69°N 3.41°W, 9 Feb. 2005, IEOCD-PISA/3023; Málaga, Calaburras-Cabo Pino, ♂ 12.7×13.06 mm, 15 m, 36.50°N 4.63°W, 18 May 2005, IEOCD-PISA/3024; Málaga, Calaburras, ♂ 12.74×13.2 mm, ♀ 8.55×10.32 mm, infralittoral, 36.50°N 4.63°W, Aug. 1991, IEOCD-PISA/3028; Málaga, Cabo Pino, ♂ 11.2×12.5 mm, 22 m, 36.50°N 4.63°W, Sept. 2004, IEOCD-PISA/3000; Granada, La Herradura, ovig ♀ 11.61×13.06 mm, 3.4 m, 36.72°N 3.75°W, Jun. 2020, IEOCD-PISA/3025; Granada, La Herradura, Marina del Este, ♂ 10.32×10.97 mm, 2-3 m, 36.72°N 3.75°W, 4 Mar. 2018, IEOCD-PISA/3026; Granada, La Herradura, ovig ♀ 15.32×15.48 mm, ovig ♀ 4.7×5.6 mm, infralittoral, 36.72°N 3.75°W, Aug. 1991, IEOCD-PISA/3027; Cádiz, La Caleta, ♂ 8.1×8.4 mm, intertidal, 36.53°N 6.31°W, 28 Oct. 2015, IEOCD-PISA/3002; Cádiz, Conil, ♂ 8.9×10.6 mm, 36.27°N 6.09°W, 14 Jul. 2015, IEOCD-PISA/3001. Morocco, ♂ 15.5×16.6 mm, 56 m, 30 Jun. 2012, CCLME2012, stn 234, 28.25°N 12.54°W, IEOCD-CCLME12/1205. Western Sahara, ♂ 17.6×17.2 mm, CCLME2012, stn 202, 68 m, 25.11°N 15.45°W, 19 Jun. 2012, IEOCD-CCLME12/1178; indet specimen (damaged), 109-110 m, CCLME2012, stn 286, 25.50°N 15.69°W, 20 Jun. 2012, IEOCD-CCLME12/1156. Mauritania, ♀ 7.9×9 mm, ♂ 10.9×12 mm, CCLME2012, stn 145, 30 m, 19.31°N 16.74°W, 8 Jun. 2012, IEOCD-CCLME12/891. Guinea-Bissau, ♂ 7.2×10.3 mm, BISSAU0811, stn 87, 38 m, 10.53°N 16.43°W, 8 Nov. 2011, IEOCD-GB08/182.

Size. Relatively small size: cl (without rostral spines) 15.97 mm in males, and 15.48 mm in females; ovigerous females from 13.06 mm cl.

Description. Specimens morphologically agree well with descriptions by Miers (1879: 11, pl. IV, Fig. 6)Miers E.J. 1879. Descriptions of new or little-known species of Majoid Crustacea (Oxyrhyncha) in the collection of the British Museum. Ann. Mag. Nat. Hist. 4: 1-28. https://www.biodiversitylibrary.org/part/63135 https://doi.org/10.1080/00222937908679780 , Monod (1956: 488-495, Figs 655-668)Monod T. 1956. Hippidea et Brachyura ouest-africains. Mem. IFAN 45: 1-674, 884 Figs, Forest and Guinot (1966: 99-103, Figs 12a, b)Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124. and Zariquiey Álvarez (1968: 453-454, Fig. 155a)Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf .

Distribution. Eastern Atlantic: from Spain to Angola (Forest and Guinot 1966Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124., d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383., Marco-Herrero et al. 2015Marco-Herrero E., Abelló P., Drake P., et al. 2015. Annotated checklist of brachyuran crabs (Crustacea: Decapoda) of the Iberian Peninsula (SW Europe). Sci. Mar. 79: 243-256. https://doi.org/10.3989/scimar.04161.27A ), including Madeira (Ramalhosa et al. 2014Ramalhosa P., Canning-Clode J., Biscoito M. 2014. First record of Pisa carinimana (Decapoda: Epialtidae) from Madeira Island (Northeastern Atlantic Ocean). Bocagiana 239: 1-7. https://publications.cm-funchal.pt/jspui/handle/100/1657 ) and the Canary Islands (González 2018González J.A. 2018. Checklists of Crustacea Decapoda from the Canary and Cape Verde Islands, with an assessment of Macaronesian and Cape Verde biogeographic marine ecoregions. Zootaxa 4413: 401-448. https://doi.org/10.11646/zootaxa.4413.3.1 ). Mediterranean: Alboran Sea (Málaga, Granada and Almería) (Zariquiey Álvarez 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf , García Raso 1990García Raso J.E. 1990. Study of a Crustacea Decapoda Taxocoenosis of Posidonia beds from the Southeast of Spain. P.S.Z.N. Mar. Ecol. 11: 309-326. https://decapoda.nhm.org/pdfs/16116/16116.pdf https://doi.org/10.1111/j.1439-0485.1990.tb00386.x , García Raso et al. 2006García Raso J.E., Martín M.J., Díaz V., et al. 2006. Diel and seasonal changes in the structure of a Decapod (Crustacea: Decapoda) community of Cymodocea nodosa from Southeastern Spain (West Mediterranean Sea). Hydrobiologia 557: 59-68. https://doi.org/10.1007/s10750-005-1308-9 ).

Habitat. On shell bottoms, gravel bottoms (Fransen 1991Fransen C.H.J.M. 1991. Preliminary report on Crustacea collected in the eastern part of the North Atlantic during the Cancap and Mauritania expeditions of the former Rijksmuseum van Natuurlike Historie, Leiden. Nationaal Natuurhistorisch Museum, Leiden: i-vi + 1-200.), sandy bottoms with algae (García Raso 1984García Raso J.E. 1984. Brachyura of the coast of Southern Spain (Crustacea, Decapoda). Spixiana 7: 105-113.), sand and muddy sand bottoms, muddy bottoms often with bryozoa or foraminifera; occasionally on hard substrates (Manning and Holthuis 1981Manning R.B., Holthuis L.B. 1981. West African Brachyuran Crabs (Crustacea: Decapoda). Smithson. Contrib. Zool. 306: 1-379. https://doi.org/10.5479/si.00810282.306 ). Between 4 (Capart 1951Capart A. 1951. Crustacés Décapodes Brachyures. Expédition océanographique Belge dans les eaux côtières africaines de l’Atlantique Sud (1948-1949). Résultats Scientifiques 3(1). Institut Royal des Sciences Naturelles de Belgique, Bruxelles, 11-205.) and 110 m depth (present work).

Remarks. Afropisa carinimana (Miers, 1879Miers E.J. 1879. Descriptions of new or little-known species of Majoid Crustacea (Oxyrhyncha) in the collection of the British Museum. Ann. Mag. Nat. Hist. 4: 1-28. https://www.biodiversitylibrary.org/part/63135 https://doi.org/10.1080/00222937908679780 ) n. comb., as the type species of the new genus Afropisa n. gen., matches the general characters described above for Afropisa n. gen. It is a small species with a subpyriform carapace; rostral spines in V-shape and divergent from the base or close to it (Figs 5G, 6G); a row of three prominent tubercles tapering posteriorly on each pterygostomian region (Fig. 7A1); and male G1 with a small finger-like process projecting inward on the outer distal plate (Fig. 7B). Additionally, A. carinimana n. comb. does not have a well-differentiated lobe in the merus of the third maxilliped at the level of the carpal insertion (Fig. 7A1, Monod 1956: Figs 658-661Monod T. 1956. Hippidea et Brachyura ouest-africains. Mem. IFAN 45: 1-674, 884 Figs), as does Pisa (Figs 7A2, 7A3).

Both morphological characteristics and the results of molecular analyses support the establishment of a new genus for P. carinimana, which has turned out to be closer to Micropisa than Pisa.

Pisa sanctaehelenae Chace, 1966: 651-654, Figs 14a-hChace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 (superseded combination).

Material examined. It was not possible to obtain specimens for the reasons mentioned in the Material and Methods section. Thus, the only information available is that mentioned in the original description by Chace (1966)Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 .

Size. A. sanctaehelenae n. comb. reaches 11.3 mm in cl (including rostral spines) in males, 8.2 mm in females, and from 5.8 mm cl in ovigerous females (Chace 1966Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 ).

Description. See Chace (1966)Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 .

Distribution. Eastern Atlantic: only known from its type locality, St. Helena Island, off Rupert’s Bay (Chace 1966Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 ).

Habitat. Collected from a buoy and cable at that location, 0-2 m depth (Chace 1966Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 ).

Remarks. According to the description and figures (Chace 1966Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 , Forest and Guinot 1966Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124.), P. sanctaehelenae exhibits similar morphological characteristics to A. carinimana n. comb., such as a subpyriform carapace (not including rostral and lateral spines) that is from one-sixth to one-third longer than wide (Chace 1966Chace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 , Forest and Guinot 1966Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124.), similar in size and relatively small. Both species bear three spines in the pterygostomial area vs one spine in Pisa. G1 of males are also similar (Chace 1966, Figs 14h-gChace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 , Forest and Guinot 1966, Figs 12a-bForest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124.), but different from those of Pisa (Zariquiey Álvarez 1968, Figs 154 a-e, 156cZariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf ).

Since DNA sequences from P. sanctaehelenae were not available for inclusion in the molecular analyses, its placement within Afropisa n. gen. could not be determined based on genetic data. However, considering its morphology, P. sanctaehelenae appears to be consistent with the characteristics of Afropisa n. gen. and could potentially be included within this new genus.

Pisa calva Forest and Guinot, 1966: 99-104, Figs 10-13Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124. (superseded combination).

Material examined. Equatorial Guinea, Annobon, ♂ 6.0×6.8 mm (cw x cl), ovig ♀ 6.5×7.5 mm, ovig ♀ 6.7×7.3 mm, ♂ 2.1×2.7 mm, ♂ 4.1×4.8 mm, ♂ 4.1×4.5 mm, ♀ 7.6×8.4 mm, ovig ♀ 5.5×6.4 mm, PILLSBURY, stn 282, 18 m, 18 May 1965, RMNH.CRUS.D.23910.

Size. A. calva n. comb. is a small species; cl (including rostral spines) is 14 mm for males and 10.5 mm for females (Forest and Guinot 1966Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124.).

Description. See Forest and Guinot (1966)Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124..

Distribution. Eastern Atlantic: São Tomé and Príncipe, and Annobon, Equatorial Guinea (Forest and Guinot 1966Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124.).

Habitat. Mainly on calcareous algae bottoms, but also on sand and mud substrates, up to 73 m depth (Forest and Guinot 1966Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124.).

Remarks. Despite the inability to obtain DNA from the tissue samples of the specimens loaned by the Naturalis Biodiversity Centre (RMNH.CRUS.D.23910), the morphological characteristics of this species differentiate it from Pisa and suggest a closer affinity to Afropisa n. gen.

The carapace regions in this species are distinguishable, but they are less pronounced than in Pisa. The prominences or tubercles, such as the cardiac, gastric and branchial ones, are less developed and do not possess sharp spines and a surrounding deep furrow as in Pisa. However, a residual intestinal furrow is present. Afropisa calva n. comb. can be differentiated by several characteristics. One notable feature is the presence of up to four spines in the sub-hepatic region, which are smaller in size than the lateral spines. This distinguishes Afropisa calva from other related species. Sparsely hairy carapace, but with clubs of hooked setae in rostral and lateral regions of carapace (Forest and Guinot 1966Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124.). Rostrum short, U-shaped rostral spines (slightly divergent) tapered towards the end and reaching the end of the antennular peduncles, but without going beyond them. Afropisa calva n. comb. exhibits a basal antennal segment with an anterior spine that is slightly visible from above. Additionally, it has an elongated tooth located just posterior to the posterolateral angle of the basal antennal segment, similar to that of A. carinimana n. comb., which is distinctly different from the tubercle-shape tooth observed in Pisa species. These characteristics serve as distinguishing features for Afropisa calva.

Although A. calva n. comb., A. carinimana n. comb. and A. sanctaehelenae n. comb. are closely related (as indicated in the genus diagnosis above), they can be easily differentiated based on the following key characteristics: A. calva n. comb. has a shorter rostrum which is divergent from its base with a U-shape vs a longer rostrum with rostral spines joined from their base that diverge sharply in A. carinimana n. comb. and A. sanctaehelenae n. comb. Afropisa calva n. comb. has two subequal laterobranchial spines vs one in A. carinimana n. comb. and four in A. sanctaehelenae n. comb.

Additionally, in comparison with other species of Pisa and even Afropisa n. gen., A. calva n. comb. exhibits a more rounded carapace (not including rostral and lateral spines). The length of the carapace is slightly greater than its width, with a ratio ranging from 1.08 to 1.16 for adult females and from 1.09 to 1.17 times for adult males, as determined from our measurements. The authors did not consider these proportions in young males. Forest and Guinot (1966)Forest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124. mentioned the ratio as being between 0.9 and 1.3 times. Its carapace is even slightly more rounded than that of A. carinimana n. comb.

Arctopsis Lamarck, 1801Lamarck J.B. 1801. Système des animaux sans vertèbres, ou tableau général des classes, des ordres et des genres de ces animaux; Présentant leurs caractères essentiels et leur distribution, d’après la considération de leurs rapports naturels et de leur organisation, et suivant l’arrangement établi dans les galeries du Muséum d’Histoire Naturelle, parmi leurs dépouilles conservées; Précédé du discours d’ouverture du Cours de Zoologie, donné dans le Muséum National d’Histoire Naturelle l’an 8 de la République. Published by the author and Deterville, Paris: viii + 432 pp. https://doi.org/10.5962/bhl.title.14255 (name supressed).

Blastus Leach, 1814Leach W.E. 1814. Crustaceology. In: Brewster D. (ed), The Edinburgh Encyclopaedia. Balfour, Edinburgh 7: 385-437. https://www.biodiversitylibrary.org/page/37187640 (junior subjective synonym).

Blastia Leach in White, 1847White A. 1847. List of the Specimens of Crustacea in the Collection of the British Museum. British Museum. London: i-viii, 1-141. https://www.biodiversitylibrary.org/page/1317596 (incorrect spelling of junior synonym).

Lissa Leach, 1815: 69-70Leach W.E. 1815. The Zoological Miscellany; Being Descriptions of New, or Interesting Animals. R.P. Nodder, London 2: 1-154, pls: 61-120. https://www.biodiversitylibrary.org/page/28685302 (junior subjective synonym).

Type species: Pisa armata (Latreille, 1803Latreille P.A. 1803. Histoire naturelle, générale et particulière des crustacés et des insectes. Paris, F. Dufart 6: 1-391, 12 pls. https://doi.org/10.5962/bhl.title.15764 https://www.biodiversitylibrary.org/page/24882091 ). Topotypic locality: Mediterranean.

Material examined. See on each species.

Modified diagnosis (Figs 5A-F, 6A-F). Carapace triangular, longer than wide. Frontal region produced as a relatively long bifid rostrum, welded at the base and diverging distally. Supraorbital margin projected forward in a protruding pre-orbital angular lobe or spine, intercalary spine present between supraorbital margin and postorbital process. Postorbital process flat plate-shaped (in dorsal view); less in P. chiragra which is lobulated (until now included in the monospecific genus Lissa). Behind postocular process, a hepatic spine with different development, from well developed to reduced or absent. Laterobranchial margins with lobes and/or spines, depending on the species.

The basal antennal segment has a tubercle-shaped tooth in the lower-outer margin. Pterygostomial region with a pair of tubercles.

Dorsal regions well defined, which can be protruding with blunt or spiniform tubercles of different shapes and developments. With protogastric tubercles well defined, central gastric region bulging and prominent, in front of which there is a small tubercle; cardiac region highly convex or swollen surrounded by a deep furrow, both not spiniform. Dorsal branchial regions with tubercles: one or two small blunt epibranchial tubercles and a blunt or somewhat projecting mesobranchial lobe. Intestinal region with median prominence, small spine or tubercle.

G1 of male slender, rather straight proximally and slightly curved subdistally, with the distal part widened and with its outer and inner lateral margins protruding upwards; the outer one is larger, wider, and more protruding than the inner one (Figs 8A-E) (Figs 154 a-e, Zariquiey Álvarez 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf ).

Remarks. Lamarck (1801)Lamarck J.B. 1801. Système des animaux sans vertèbres, ou tableau général des classes, des ordres et des genres de ces animaux; Présentant leurs caractères essentiels et leur distribution, d’après la considération de leurs rapports naturels et de leur organisation, et suivant l’arrangement établi dans les galeries du Muséum d’Histoire Naturelle, parmi leurs dépouilles conservées; Précédé du discours d’ouverture du Cours de Zoologie, donné dans le Muséum National d’Histoire Naturelle l’an 8 de la République. Published by the author and Deterville, Paris: viii + 432 pp. https://doi.org/10.5962/bhl.title.14255 established Arctopsis in a rather vague manner (withouth specifying the capture location), while Pisa was well described and had been used for many years. Afterward, Arctopsis was mentioned by Gray (1850)Gray J.E. 1850. List of the specimens of British animals in the collection of the British Museum, Part IV. Crustacea. https://doi.org/10.5962/bhl.title.1582 in his list of crab specimens in the British Museum, and he considered Cancer biaculeatus Montagu, 1813Montagu G. 1813. Descriptions of several new or rare animals, principally marine, discovered on the South coast of Devonshire. Trans. Linn. Soc. Lond. 11: 1-26, pls. 1-5. https://doi.org/10.1111/j.1096-3642.1813.tb00035.x , P. biaculeata Leach, 1814Leach W.E. 1814. Crustaceology. In: Brewster D. (ed), The Edinburgh Encyclopaedia. Balfour, Edinburgh 7: 385-437. https://www.biodiversitylibrary.org/page/37187640 and P. gibbsii Leach, 1815 as synonyms of this species. Moreover, Gray (1850)Gray J.E. 1850. List of the specimens of British animals in the collection of the British Museum, Part IV. Crustacea. https://doi.org/10.5962/bhl.title.1582 also synonymized Arctopsis tetraodon with P. tetraodon. White (1857: 14, 21)White A. 1857. A popular history of British Crustacea; comprising a familiar account of their classification and habits. Ann. Mag. Nat. Hist. 20: 116, 141. https://doi.org/10.1080/00222935709487891 https://doi.org/10.5962/bhl.title.14410 , in his list of crustacean specimens in the Collection of the British Museum (mainly based on the same material already listed by Gray 1850Gray J.E. 1850. List of the specimens of British animals in the collection of the British Museum, Part IV. Crustacea. https://doi.org/10.5962/bhl.title.1582 ), added two records of A. lanata from the Isle of Man and Guernsey, and illustrated the species. His figure closely resembles P. armata. Apart from White (1857)White A. 1857. A popular history of British Crustacea; comprising a familiar account of their classification and habits. Ann. Mag. Nat. Hist. 20: 116, 141. https://doi.org/10.1080/00222935709487891 https://doi.org/10.5962/bhl.title.14410 , no one else has recorded this species since its description.

Holthuis (1962)Holthuis L.B. 1962. Arctopsis Lamarck, 1801 (Crustacea, Decapoda); proposed suppression under the plenary powers, and related matters. Z.N. (S.) 1498. Bull. Zool. Nomencl. 19: 184-188. https://www.biodiversitylibrary.org/item/44461#page/7/mode/1up dealt with the issue of Arctopsis Lamarck, 1801Lamarck J.B. 1801. Système des animaux sans vertèbres, ou tableau général des classes, des ordres et des genres de ces animaux; Présentant leurs caractères essentiels et leur distribution, d’après la considération de leurs rapports naturels et de leur organisation, et suivant l’arrangement établi dans les galeries du Muséum d’Histoire Naturelle, parmi leurs dépouilles conservées; Précédé du discours d’ouverture du Cours de Zoologie, donné dans le Muséum National d’Histoire Naturelle l’an 8 de la République. Published by the author and Deterville, Paris: viii + 432 pp. https://doi.org/10.5962/bhl.title.14255 and A. lanata and used the diagnosis of the synonymous Pisa instead of Arctopsis, considering this as a nomen dubium. Consequently, the name Arctopsis was supressed according to the Law of Priority but not the Law of Homonymy (China 1964: 208-209China W.E. 1964. Opinion 708. Arctopsis Lamarck, 1801 (Crustacea, Decapoda): suppressed under the plenary powers. Bull. Zool. Nomencl. 21: 208-209. https://www.biodiversitylibrary.org/page/12222061., Opinion 708, ICZN), and P. armata became the type species of Pisa.

According to our molecular and morphological data, the genus Pisa should be restricted to P. armata, P. chiragra n. comb., P. hirticornis, P. muscosa, P. nodipes and P. tetraodon.

Arctopsis lanata Lamarck, 1801Lamarck J.B. 1801. Système des animaux sans vertèbres, ou tableau général des classes, des ordres et des genres de ces animaux; Présentant leurs caractères essentiels et leur distribution, d’après la considération de leurs rapports naturels et de leur organisation, et suivant l’arrangement établi dans les galeries du Muséum d’Histoire Naturelle, parmi leurs dépouilles conservées; Précédé du discours d’ouverture du Cours de Zoologie, donné dans le Muséum National d’Histoire Naturelle l’an 8 de la République. Published by the author and Deterville, Paris: viii + 432 pp. https://doi.org/10.5962/bhl.title.14255 (name supressed); White 1847: 6White A. 1847. List of the Specimens of Crustacea in the Collection of the British Museum. British Museum. London: i-viii, 1-141. https://www.biodiversitylibrary.org/page/1317596 (list); White 1857: 21, pl. 1 Fig. 2White A. 1857. A popular history of British Crustacea; comprising a familiar account of their classification and habits. Ann. Mag. Nat. Hist. 20: 116, 141. https://doi.org/10.1080/00222935709487891 https://doi.org/10.5962/bhl.title.14410 ; Holthuis 1962c: 184Holthuis L.B. 1962. Arctopsis Lamarck, 1801 (Crustacea, Decapoda); proposed suppression under the plenary powers, and related matters. Z.N. (S.) 1498. Bull. Zool. Nomencl. 19: 184-188. https://www.biodiversitylibrary.org/item/44461#page/7/mode/1up (discussion); China 1964: 208China W.E. 1964. Opinion 708. Arctopsis Lamarck, 1801 (Crustacea, Decapoda): suppressed under the plenary powers. Bull. Zool. Nomencl. 21: 208-209. https://www.biodiversitylibrary.org/page/12222061. (name suppressed under the plenary powers).

Maia armata Latreille, 1803Latreille P.A. 1803. Histoire naturelle, générale et particulière des crustacés et des insectes. Paris, F. Dufart 6: 1-391, 12 pls. https://doi.org/10.5962/bhl.title.15764 https://www.biodiversitylibrary.org/page/24882091 (superseded combination); China 1964: 208China W.E. 1964. Opinion 708. Arctopsis Lamarck, 1801 (Crustacea, Decapoda): suppressed under the plenary powers. Bull. Zool. Nomencl. 21: 208-209. https://www.biodiversitylibrary.org/page/12222061. (placed on the Official List of Specific Names in Zoology, name No. 1987).

Cancer biaculeatus Montagu, 1813Montagu G. 1813. Descriptions of several new or rare animals, principally marine, discovered on the South coast of Devonshire. Trans. Linn. Soc. Lond. 11: 1-26, pls. 1-5. https://doi.org/10.1111/j.1096-3642.1813.tb00035.x (junior subjective synonym).

Pisa gibbsii Leach, 1816Leach W.E. 1816. A tabular View of the external Characters of Four Classes of Animals, which Linné arranged under Insecta; with the Distribution of the Genera comprising Three of these Classes into Orders, and Descriptions of several New Genera and Species. Trans. Linn. Soc. Lond. 11: 306-400. https://doi.org/10.1111/j.1096-3642.1813.tb00065.x https://www.biodiversitylibrary.org/bibliography/119762 (junior subjective synonym).

Blastia tridens Leach in White, 1847White A. 1847. List of the Specimens of Crustacea in the Collection of the British Museum. British Museum. London: i-viii, 1-141. https://www.biodiversitylibrary.org/page/1317596 (not available name, ICZN Article 11.6).

Material examined. Portugal, Azores, ovig ♀, 23.9×26.0 mm, MMF 23698. Spain, Cádiz, ♂ 23.5×31 mm, ARSA1115 stn 43, 36.01°N 6.44°W, Nov. 2015, IEOCD-AR15/2551; Cádiz, ♂ 9.5×14 mm, ♂ 9.8×11.6 mm, ARSA1116 stn 37, 36.01°N 6.44°W, Nov. 2016, IEOCD-AR16/2552; Canary Islands, ♀ 12.3×13.3 mm, CIRCAN2020 stn 37, 70 m, 27.80°N 15.82°W, 29 Nov. 2020, IEOCD-CIRCAN20/3015; Menorca, Maó, ♀ damaged, 72 m, 39.82°N 4.37°E, 29 Jan. 2014, ICMD000864; Menorca, Maó, ♂ 8×10 mm, MAO14 stn 129, 39.82°N 4.37°E, 1 May 2015, IEOCD-PISA/3003; Menorca, Maó, ♂ 9.2×10.6 mm, MAO14 stn 7, 39.82°N 4.37°E, 16 May 2015, IEOCD-PISA/3004; Canary Islands, Fuerteventura, 9 Jul. 2010, IEOCD-PISA/292. Western Sahara, indet 15.1×15.6 mm, CCLME12, stn 157, 206 m, 25.52°N 15.67°W, 20 Jun. 2012, IEOCD-CCLME12/1156; damaged, CCLME11 stn 171, 113 m, 22.63°N 17.46°W, 21 Nov. 2011, IEO-CD-CCLME11/958; ovig ♀ 21.5×22.0 mm, ♂ 23.8×23.5 mm, CCLME12 stn 106, 179 m, 22.68°N 17.18°W, 14 Jun. 2012, IEO-CD-CCLME12/1152. Mauritania, ♂ 27.1×28.5 mm, LANGAMAU0114 stn 1, 275 m, 18.88°N 16.78°W, 22 Mar. 2014, IEOCD-LANGAMAU/2181; ♀ 18.8×20.4 mm, CCLME11 stn 112, 169 m, 17.09°N 16.96°W, 20 Nov. 2011, IEOCD-CCLME11/1959. Guinea-Bissau, ♀ 27.7×27.8 mm, ♂ 24.6×25.3 mm, BISSAU0811 stn 5, 102-105 m, 11.48°N 17.19°W, 23 Oct. 2008, IEOCD-GB08/179; ♂ 29.0×31.3 mm, BISSAU0811 stn 69, 65-70 m, 10.28°N 16.37°W, 4 Nov. 2008, IEOCD-GB08/180; ♂ 29×31.2 mm, BISSAU0811 stn 69, 65-70 m, 10.28°N 16.37°W, 4 Nov. 2008, IEOCD-GB08/180. Guinea, ♂ 27.2×28.9 mm, CCLME12, stn 2, 94 m, 8.95°N 14.62°W, 10 May 2012, IEOCD-CCLME12/1594. Sierra Leone, ♀ 24.1×26 mm, GUINEA90 stn 71, 55-60 m, 7.25°N 13.20°W, 13 Apr. 1990, IEOCD-PISA/3030. Liberia, ♂ 35.1×38 mm, GUINEA90 stn 35, 44-47 m, 5.44°N 10.04°W, 6 Apr. 1990, IEOCD-PISA/3031. Equatorial Guinea, Bioko, ♀ 27.8×29 mm, GECUAT0817 stn 7, 63 m, 3.67°N 8.98°E, 8 Aug. 2017, IEOCD-GE17/2133.

Distribution. Eastern Atlantic: from British Isles and south of North Sea to Angola (Manning and Holthuis 1981Manning R.B., Holthuis L.B. 1981. West African Brachyuran Crabs (Crustacea: Decapoda). Smithson. Contrib. Zool. 306: 1-379. https://doi.org/10.5479/si.00810282.306 , d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383., Muñoz et al. 2012Muñoz I., García-Isarch E., Sobrino I., et al. 2012. Distribution, abundance and assemblages of decapod crustaceans in waters off Guinea-Bissau (north-west Africa). J. Mar. Biol. Assoc. U. K. 92(3): 475-494. https://doi.org/10.1017/S0025315411001895 ), including the Azores (Fransen 1991Fransen C.H.J.M. 1991. Preliminary report on Crustacea collected in the eastern part of the North Atlantic during the Cancap and Mauritania expeditions of the former Rijksmuseum van Natuurlike Historie, Leiden. Nationaal Natuurhistorisch Museum, Leiden: i-vi + 1-200.), Canary (González 2016González J.A. 2016. Brachyuran crabs (Crustacea: Decapoda) from the Canary Islands (eastern Atlantic): checklist, zoogeographic considerations and conservation. Sci. Mar. 80: 89-102. https://doi.org/10.3989/scimar.04350.10A , 2018González J.A. 2018. Checklists of Crustacea Decapoda from the Canary and Cape Verde Islands, with an assessment of Macaronesian and Cape Verde biogeographic marine ecoregions. Zootaxa 4413: 401-448. https://doi.org/10.11646/zootaxa.4413.3.1 ) and Cape Verde islands (Fransen 1991Fransen C.H.J.M. 1991. Preliminary report on Crustacea collected in the eastern part of the North Atlantic during the Cancap and Mauritania expeditions of the former Rijksmuseum van Natuurlike Historie, Leiden. Nationaal Natuurhistorisch Museum, Leiden: i-vi + 1-200.). Mediterranean: many records from both western and eastern basins (Pipitone and Tumbiolo 1993Pipitone C., Tumbiolo M.L. 1993. Decapod and stomatopod crustaceans from the trawlable bottoms of the Sicilian Channel (central Mediterranean Sea). Crustaceana 65(3): 358-364. https://decapoda.nhm.org/pdfs/26390/26390.pdf https://doi.org/10.1163/156854093X00784 , d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.).

Habitat. On sandy shell bottoms (Fransen 1991Fransen C.H.J.M. 1991. Preliminary report on Crustacea collected in the eastern part of the North Atlantic during the Cancap and Mauritania expeditions of the former Rijksmuseum van Natuurlike Historie, Leiden. Nationaal Natuurhistorisch Museum, Leiden: i-vi + 1-200.), coralligenous and detrital substrates (Moncharmont 1979Moncharmont U. 1979-1981. Notizie biologiche e faunistiche sui Crostacei Decapodi del Golfo di Napoli. Annu. Ist. Mus. Zool. Univ. Napoli 22-23: 33-132.), and muddy sandy bottoms (García Raso 1984García Raso J.E. 1984. Brachyura of the coast of Southern Spain (Crustacea, Decapoda). Spixiana 7: 105-113.). Between 18 (García Raso 1984García Raso J.E. 1984. Brachyura of the coast of Southern Spain (Crustacea, Decapoda). Spixiana 7: 105-113.) and 206 m depth (present work).

Remarks. The holotype or specimens preserved under the name Arctopsis lanata, and from the topotypical locality, are no longer available, and therefore no comparison is possible. The original description by Lamarck (1801: 155)Lamarck J.B. 1801. Système des animaux sans vertèbres, ou tableau général des classes, des ordres et des genres de ces animaux; Présentant leurs caractères essentiels et leur distribution, d’après la considération de leurs rapports naturels et de leur organisation, et suivant l’arrangement établi dans les galeries du Muséum d’Histoire Naturelle, parmi leurs dépouilles conservées; Précédé du discours d’ouverture du Cours de Zoologie, donné dans le Muséum National d’Histoire Naturelle l’an 8 de la République. Published by the author and Deterville, Paris: viii + 432 pp. https://doi.org/10.5962/bhl.title.14255 was very vague and without illustration, but in White (1857: 21, plate I,2)White A. 1857. A popular history of British Crustacea; comprising a familiar account of their classification and habits. Ann. Mag. Nat. Hist. 20: 116, 141. https://doi.org/10.1080/00222935709487891 https://doi.org/10.5962/bhl.title.14410 there is a figure that closely resembles P. armata. Consequently, following the opinion of Holthuis (1962)Holthuis L.B. 1962. Arctopsis Lamarck, 1801 (Crustacea, Decapoda); proposed suppression under the plenary powers, and related matters. Z.N. (S.) 1498. Bull. Zool. Nomencl. 19: 184-188. https://www.biodiversitylibrary.org/item/44461#page/7/mode/1up and China (1964: 208-209, Opinion 708, ICZN)China W.E. 1964. Opinion 708. Arctopsis Lamarck, 1801 (Crustacea, Decapoda): suppressed under the plenary powers. Bull. Zool. Nomencl. 21: 208-209. https://www.biodiversitylibrary.org/page/12222061., as mentioned above, the generic name Arctopsis and the specific name lanata are supressed. Thus, the valid name of the genus is Pisa (Lamark 1814), and the type species is Maja armata (Latreille 1803Latreille P.A. 1803. Histoire naturelle, générale et particulière des crustacés et des insectes. Paris, F. Dufart 6: 1-391, 12 pls. https://doi.org/10.5962/bhl.title.15764 https://www.biodiversitylibrary.org/page/24882091 ).

Cancer cruentatus Linnaeus, 1758Linnaeus C. 1758. Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata [10th revised edition], 1: 824 pp. Laurentius Salvius: Holmiae. https://doi.org/10.5962/bhl.title.542 https://www.biodiversitylibrary.org/bibliography/559 (suppressed under ICZN Opinion 522).

Cancer chiragra Fabricius, 1775Fabricius J.C. 1775. Systema Entomologiae, sistens Insectorum Classes, Ordines, Genera, Species, adjectis Sysnonymis, Locis, Descriptionibus, Observationibus. Kortii, Flensburgi et Lipsiae. 832 pp. https://doi.org/10.5962/bhl.title.36510 (superseded combination).

Lissa chiragra Fabricius, 1775Fabricius J.C. 1775. Systema Entomologiae, sistens Insectorum Classes, Ordines, Genera, Species, adjectis Sysnonymis, Locis, Descriptionibus, Observationibus. Kortii, Flensburgi et Lipsiae. 832 pp. https://doi.org/10.5962/bhl.title.36510 (superseded combination).

Material examined. Spain, Balearic Islands, Maó, ovig ♀ 23.5×28.7 mm, ♀ 20×27 mm, MEDITS0522 stn 238, 57 m, 39.82°N 4.20°E, 2 Jul. 2022, IEOCD-MEDITS22/295; Balearic Islands, Sóller, ovig ♀, damaged, MEDITS0522, stn 201, 60 m, 39.86°N 2.77°E, 21 Jun. 2022, IEOCD-MEDITS22/296; Murcia, Cartagena, ovig ♀, 25.3×24.3 mm, 44 m, 37.53°N 0.80°W, 13 May 2004, ICMD001011; Murcia, Cartagena, ovig ♀, 31.9×32.4 mm, 46 m, 37.48°N 0.37°W, 2 Jun. 2000, ICMD297/2000; Balearic Islands, Santanyi, juv ♀, 10.1×13.5 mm, MEDITS0522, stn 93, 195 m, 39.31°N 3.26°E, 22 Jun. 2022, IEOCD-MEDITS22/300.

Distribution. Eastern Atlantic: south of Portugal (Sines, and Portimão) (Guerra and Gaudêncio 1981Guerra Μ.T., Gaudêncio M.J. 1981. Lissa chiragra (Fabricius, 1981) (Crustacea Decapoda Majidae), un crustacé nouveau pour l’Atlantique Oriental. Memórias do Museum do Mar, Sér. Zoológica 2: 1-6.). Mediterranean: many records from both western and eastern basins (Pipitone and Tumbiolo 1993Pipitone C., Tumbiolo M.L. 1993. Decapod and stomatopod crustaceans from the trawlable bottoms of the Sicilian Channel (central Mediterranean Sea). Crustaceana 65(3): 358-364. https://decapoda.nhm.org/pdfs/26390/26390.pdf https://doi.org/10.1163/156854093X00784 ; d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.).

Habitat. On coralline bottoms (Pérès and Picard 1964Pérès J.M., Picard J. 1964. Nouveau manuel de bionomie benthique. Recl. Trav. Stn. Mar. Endoume 31(47): 5-137. http://paleopolis.rediris.es/benthos/REF/som/R-pdf/Manuel_bionomie_benthique_1964.pdf ); detrital substrates and mud bottoms (Števčić 1990Števčić Z. 1990. Checklist of the Adriatic Decapod Crustacea. Acta Adriat. 31(1-2): 183-274. https://decapoda.nhm.org/pdfs/22976/22976.pdf ). Between 14 (Števčić 1990Števčić Z. 1990. Checklist of the Adriatic Decapod Crustacea. Acta Adriat. 31(1-2): 183-274. https://decapoda.nhm.org/pdfs/22976/22976.pdf ) and 195 m depth (present work), mainly between 20 and 40 m (Zariquiey Álvarez 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf ).

Remarks. The morphological characters used by Leach (1815)Leach W.E. 1815. The Zoological Miscellany; Being Descriptions of New, or Interesting Animals. R.P. Nodder, London 2: 1-154, pls: 61-120. https://www.biodiversitylibrary.org/page/28685302 to separate Lissa chiragra (Fabricius, 1775Fabricius J.C. 1775. Systema Entomologiae, sistens Insectorum Classes, Ordines, Genera, Species, adjectis Sysnonymis, Locis, Descriptionibus, Observationibus. Kortii, Flensburgi et Lipsiae. 832 pp. https://doi.org/10.5962/bhl.title.36510 ) from Pisa species were carapace naked, rostral spines contiguous and chelipeds not denticulate on the inside. However, after analysis, it may be concluded that these characters are no longer valid or sufficiently distinctive. The carapace is practically naked (with few hooked and mace setae) in P. hirticornis, P. muscosa, P. tetraodon and P. chiragra n. comb., while in P. armata and P. nodipes it has dense short, pile-like setae with clusters of larger hook setae on the raised areas (bumps, spines, etc.). The rostral spines meet from the base and diverge at the apex in all Pisa species. The same pattern is observed in P. chiragra n. comb., where the rostral spines remain fused but are truncated at the apex. P. chiragra n. comb. exhibits small lobes or teeth on the fixed and movable fingers of P1, which are not visible when the chelipeds are closed, while the other species have more pronounced teeth. Additionally, some adult males of P. chiragra n. comb. may display a significant hiatus (gap) in their chelipeds, similar to P. nodipes and P. tetraodon.

Within the Epialtidae, the presence of spines and tubercles in many of the carapace regions is very common. A detailed study of the spine-tubercles distributed over the carapace of the Pisa species shows a similar configuration (Fig. 5). What sets P. chiragra n. comb. apart from all other Pisa species is the presence of numerous robust tubercles on its carapace. These tubercles are further covered by smaller-sized ones, giving them the appearance of calcareous algae formations. This distinctive characteristic distinguishes P. chiragra n. comb. from other species within the genus. The development of tubercles in P. chiragra n. comb. can vary, and it may be related to specimen size. Larger individuals tend to have larger and more massive tubercles (Figs 5C2-3) than smaller individuals (Fig. 5C1). Thus, the carapace of juvenile individuals of P. chiragra n. comb. exhibits similarities with that of P. nodipes (Figs 5C1 and B)

All Pisa species have a prominent and large mesogastric protuberance and several cardiac protuberances along the longitudinal mesial line. Additionally, P. armata has an intestinal acute spine (Figs 5A, 6A), P. nodipes has a well-developed blunt tubercle (Figs 5B, 6B), and P. chiragra n. comb. has a large bilobed tubercle (Figs 5C1-C3, 6F). Anteriorly to the largest gastric protuberance, a small tubercle is present in P. muscosa, P. tetraodon, P. armata, P. nodipes and P. hirticornis. However, in P. chiragra n. comb. (Figs 5A-F), this feature is not clearly distinguishable because the massive gastric tubercle is composed of smaller tubercles. Nonetheless, in some specimens of P. chiragra n. comb. two small tubercles may be observed (Fig. 5C2, IEOCD-MEDITS22/295).

All Pisa species have some well-defined small tubercles arranged transversally on the protogastric region. Pisa muscosa has four, P. tetraodon, P. hirticornis and P. chiragra n. comb. have five (two lateral ones on both sides and one in the middle, somewhat in front), while P. nodipes and P. armata show four poorly defined tubercles (with a very slightly protruding mesial area, but no tubercle) (Figs 5A-F).

The lateral margin of the branchial region in P. nodipes and P. armata is characterized by having only one posterior spine. In P. tetraodon, P. hirticornis, and P. muscosa, there are three spines, with the anterior one being smaller and sometimes lobed as in P. muscosa. In the case of P. chiragra n. comb., the lateral margin of the branchial region is composed of big lobes that are compounded by smaller tubercles.

There are distinct differences among Pisa species in the morphology of the posterior branchial spine on the carapace and towards the inner side (on both sides of the cardiac tubercle). P. muscosa has a single protruding lobe or blunt spine, while P. armata and P. nodipes have a slightly protruding area in this region. P. tetraodon and P. hirticornis have two protruding areas, with P. tetraodon showing a more pronounced outer area and P. hirticornis showing a more pronounced inner area. In some cases, the outer area may be indistinguishable, particularly in small specimens, if the seta has fallen. P. chiragra n. comb. is characterized by having large metabranchial tubercles.

The anterior inner branchial region (epibranchial) also exhibits differences among these species: P. nodipes and P. armata both have two blunt protuberances, with the posterior-outer protuberance being larger and bilobed or trilobed, while in front of it there is another smaller protuberance. P. tetraodon has a single protuberance, and in front of it there is a small non-protruding defined area with hooked setae. P. muscosa and P. hirticornis have a single protuberance each, while P. chiragra n. comb. has a large tuberculate bulk in this region.

The male G1 of P. chiragra n. comb. exhibits morphological similarities to that of other species within the genus Pisa. It is characterized by a widened distal part, with the outer side being larger and protruding upwards compared with the inner side (Fig. 8D, Fig. 156c in Zariquiey Álvarez 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf ).

Moreover, Guerao et al. (2003)Guerao G., Rufino M., Abelló P. 2003. Morphology of the larval and first juvenile stages of the spider crab Lissa chiragra (Brachyura: Majidae: Pisinae). J. Nat. Hist. 37: 647-671. https://doi.org/10.1080/00222930110116048 described and illustrated the two zoeae, megalopa and first crab stage of Pisa chiragra n. comb. (as Lissa chiragra) and compared them with other known larval descriptions of Pisinae. They concluded that the morphology of all these larval stages is very similar to that of the other larvae of the genus Pisa. In fact, they mentioned that it is impossible to separate the larvae of L. chiragra from those of Pisa. This observation, along with the molecular evidence and analysis of adult morphological characters discussed above, further supports the inclusion of Lissa chiragra within the genus Pisa.

Cancer hirticornis Herbst, 1804Herbst J.F.W. 1804. Versuch einer Naturgeschichte der Krabben und Krebse, nebst einer systematischen Beschreibung ihrer verschiedenen Arten. Berlin und Stralsund, Gottlieb, August und Lange. 3(4): 1-49, pls. LIX-LXII. https://doi.org/10.5962/bhl.title.64679 (superseded combination).

Maia corallina Risso, 1816Risso A. 1816. Histoire Naturelle des Crustacés des Environs de Nice. Librairie GrecqueLatine-Allemande, Paris. 175 pp., 3 pls. https://doi.org/10.5962/bhl.title.8992 (junior subjective synonym).

Pisa corallina (Risso, 1816Risso A. 1816. Histoire Naturelle des Crustacés des Environs de Nice. Librairie GrecqueLatine-Allemande, Paris. 175 pp., 3 pls. https://doi.org/10.5962/bhl.title.8992 ) (junior subjective synonym).

Pisa intermedia Nardo, 1847Nardo G.D. 1847. Sinonimia Moderna delle Specie Regisrate nell’Opera Intitolata: Descrizione de’Crostacei, de’Testacei e de’Pesci che Abitano le Lagune e Golfo Veneto Rappressentati in Figure, a Chiaro-scuro ed a Colori dall’Abate Stefano Chiereghini Ven. Clodiense. Antonelli: Venezia. [According to Carlo Froglia, the Prospetto and the Sinonimia were published simultaneously; the Sinonimia is here considered to have priority.]. http://books.google.es/books?id=wU09AAAAYAAJ https://doi.org/10.5962/bhl.title.120206 (nomen nudum); Nardo, 1869 (junior subjective synonym).

Material examined. Spain, Girona, Cadaqués, ♀ 28.5×30.4 mm, 43.28°N 3.28°E, 22 Jul. 1953, ICMZ2040/2016; ♂ 25.2×27.3 mm, 7 Nov. 1958, ICMZ2058/2016; ♀ 24.9×27.0 mm, 15 Jan. 1958, ICMZ2070/2016; ♀ 11.5×12.8 mm, ICMZ13887/2017; ♀ 9.6×10.7 mm, ♀ 9×10.5 mm, ♀ 9.2×10.9 mm, Sep. 1952, ICMZ2244, 45, 46, 47; ♀ 14×15.7 mm, ♀ 14.2×15.8 mm, ICMZ14020-21/2017.

Distribution. Mediterranean: western basin (Forest 1966Forest J. 1966. Campagnes du “Professeur Lacaze-Duthiers” aux Baléares : Juin 1953 et août 1954. Crustacés décapodes. Vie et Milieu, série B, Océanographie 16 (1B) [for 1965]: 325-413. https://decapoda.nhm.org/pdfs/15928/15928.pdf , Zariquiey Álvarez 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf , Grippa 1993Grippa G.B. 1993. Notes on decapod fauna of ‘‘Arcipelago Toscano’’. Bios (Macedonia, Greece), Sci. Ann. School Biol. 1: 223-239.) and many records from the eastern basin (d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.). Probably absent from Alboran Sea (García Raso et al. 1987García Raso J.E., González-Gurriarán E., Sardá F. 1987. Estudio comparativo de la fauna de crustáceos decápodos braquiuros de tres áreas de la Península Ibérica (Galicia, Málaga, Cataluña). Invest. Pesq. 51(Supl. 1): 43-55. https://digital.csic.es/handle/10261/157109 ).

Habitat. Posidonia bottoms, chiefly between 5 and 10 m depth (Zariquiey Álvarez 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf ), although it can reach a depth of 37 m (Lewinsohn and Holthuis 1986Lewinsohn C., Holthuis L.B. 1986. The Crustacea Decapoda of Cyprus. Zool. Verh. 230: 1-64. https://doi.org/10.1017/S1755267209990911 ).

Remarks. Pisa hirticornis and P. tetraodon are closely related species with many similar morphological characters (Sakai 1999Sakai K. 1999. J. F. W. Herbst-Collection of Decapod Crustacea of the Berlin Zoological Museum, with remarks on certain species. Naturalists, Publications of Tokushima Biological Laboratory, Shikoku University 6: 1-45, pls 1-21.). They are so similar that some authors have considered them as synonyms (Nardo 1869Nardo G.D. 1869. Annotazioni illustranti cinquantaquattro specie di crostacei podottalmi, endottalmi e succhiatori del mare Adriatico, alcune delle quali nuove o male conosciute, accompagnate da trentatre figure litografate, e precedute dalla storia della carcinologia adriatica antica e recente. Memorie dell Reale Istituto Veneto di Scienze (Lettere ed Arti) 14: 217-343. https://doi.org/10.5519/0002965. https://doi.org/10.5962/bhl.title.10261 , Pesta 1918Pesta O. 1918. Die Decapodenfauna der Adria. Versuch einer Monographie, F. Deuticke. Wien-Leipzig. https://www.biodiversitylibrary.org/bibliography/16144 https://doi.org/10.5962/bhl.title.16144 ). Forest (1966)Forest J. 1966. Campagnes du “Professeur Lacaze-Duthiers” aux Baléares : Juin 1953 et août 1954. Crustacés décapodes. Vie et Milieu, série B, Océanographie 16 (1B) [for 1965]: 325-413. https://decapoda.nhm.org/pdfs/15928/15928.pdf also questioned the validity of P. hirticornis and suggested that it might actually represent a variable form of P. tetraodon. This was in line with the earlier observations by Zariquiey Álvarez (1959)Zariquiey Álvarez R. 1959. Crustáceos Decápodos de la región de Cadaqués. II Parte. Misc. Zool. 1(2): 1-7. https://decapoda.nhm.org/pdfs/30246/30246.pdf , who noted the similarity between P. hirticornis, P. tetraodon and P. muscosa. However, Forest later accepted the species status of P. hirticornis.

Though P. hirticornis is considered a good species and is supported by strong molecular evidence in the present study, a morphological review of specimens from the Zariquiey Collection (CBMR, ICM-CSIC) collected between the 1950s and the 1960s from Cadaqués (NW Mediterranean) raises questions about the relevance of all the characters that were previously assigned to P. hirticornis and P. tetraodon by Zariquiey Álvarez (1959Zariquiey Álvarez R. 1959. Crustáceos Decápodos de la región de Cadaqués. II Parte. Misc. Zool. 1(2): 1-7. https://decapoda.nhm.org/pdfs/30246/30246.pdf , 1968)Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf . After examining 54 specimens of Pisa species from the Zariquiey Collection (see examined material), it was observed that there were some misidentifications of P. hirticornis. Out of the 29 individuals initially assigned to this species in the collection, only seven were confirmed to be P. hirticornis, while the rest were subsequently identified as P. muscosa. This suggests that there may have been confusion or mislabeling of specimens in the collection, leading to incorrect identifications.

It is noted that some of the characters used by Zariquiey Álvarez in his key (Zariquiey Álvarez 1959Zariquiey Álvarez R. 1959. Crustáceos Decápodos de la región de Cadaqués. II Parte. Misc. Zool. 1(2): 1-7. https://decapoda.nhm.org/pdfs/30246/30246.pdf , 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf ) to distinguish P. hirticornis from P. tetraodon may not be reliable features. Specifically, the description of P. hirticornis in the key includes “sharp hepatic spine, pointing crosswise out” (Forest 1966Forest J. 1966. Campagnes du “Professeur Lacaze-Duthiers” aux Baléares : Juin 1953 et août 1954. Crustacés décapodes. Vie et Milieu, série B, Océanographie 16 (1B) [for 1965]: 325-413. https://decapoda.nhm.org/pdfs/15928/15928.pdf ) and “branchial margin spines sharp and pointing out, not curved”. However, based on the examination of specimens from the Zariquiey Collection, it has been observed that these characters may not consistently differentiate between P. hirticornis and P. tetraodon. After conducting a comprehensive review of the seven examined specimens of P. hirticornis, we concluded that the hepatic spine is not always straight and directed outwards but may be slightly curved, especially in large specimens; and the second and third lateral spines in branchial region can also be curved. In fact, the second lateral spine is slightly curved upwards in five specimens, and in four crabs the third lateral spine is curved upwards, more markedly in large specimens. Based on our examination and analysis, we have reached the conclusion that the most reliable character for distinguishing between P. hirticornis and P. tetraodon is the morphology of the rostral spines. In P. hirticornis, the rostral spines are long, contiguous, and only diverge distally, while in P. tetraodon, the rostral spines are shorter and diverge from the middle. Additionally, we have observed that the inner setiferous tubercle of the posterior branchial region is larger in P. hirticornis (Forest 1966Forest J. 1966. Campagnes du “Professeur Lacaze-Duthiers” aux Baléares : Juin 1953 et août 1954. Crustacés décapodes. Vie et Milieu, série B, Océanographie 16 (1B) [for 1965]: 325-413. https://decapoda.nhm.org/pdfs/15928/15928.pdf ) than in P. tetraodon. These distinct characteristics provide a more definitive means of separating the two species.

Cancer muscosa Linnaeus, 1758Linnaeus C. 1758. Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata [10th revised edition], 1: 824 pp. Laurentius Salvius: Holmiae. https://doi.org/10.5962/bhl.title.542 https://www.biodiversitylibrary.org/bibliography/559 (superseded combination).

Maja ambigua A. Costa, 1840Costa A. 1840. Statistica fisica ed economica dell’Isola di Capri. 7. Crostacei. Esercitazioni accademiche degli Aspiranti Naturalisti, Napoli 2: 73-77, pl. IV. https://www.biodiversitylibrary.org/page/9238427 (junior subjective synonym).

Material examined. Spain, Girona, Cadaqués, ♂ 12×13.1 mm, 43.28°N 3.28°E, 8 May 1955, ICMZ2065/2016; ♂ 8.4×10.4 mm, 9 May 1956, ICMZ2066/2016; ♂ 13.2×14.9 mm, 16 Aug. 1948, ICMZ2251/2016; ovig ♀ 12.4×13.9 mm, ♀ 11.4×12.6 mm, 16 Aug. 1948, ICMZ2253/2016; ♀ 6.4×8.4 mm, ♂ 12.8×15.1 mm, ♂ 11.4×12.4 mm, 27 Jul. 1950, ICMZ2296/2016 and ICMZ2298/2016; ovig ♀ 11.7×13.3 mm, ♀ 13.4×14.9 mm, 3 Aug. 1954, ICMZ2234/2016 and ICMZ2235/2016; ♀ 7.2×9.8 mm, ♂ 11.7×13.1 mm, Aug. 1947, ICMZ2302/2016 and ICMZ2303/2016; ♂ 13.5×15.1 mm, Sep. 1952, ICMZ2244-47; ♀ 11.5×13.5 mm, ♀ 10.7×12 mm, ♀ 12.4×13.3 mm, ♀ 5.8×6.7 mm, ♀ 5.7×7.1 mm, Aug. 1951, ICMZ2237/2016 and ICMZ2241/2016; ♂ 12×13.2 mm, ♂ 8.6×10.1 mm, Aug. 1954, ICMZ2265/2016 and ICMZ2266/2016; ♀ 7.1×8.6 mm, ♀ 8.9×10.7 mm, 7 Sep. 1959, ICMZ1934-36/2016; Balearic Islands, Santanyi, ♂ 10×1.7 mm, MEDITS0522 stn 195, 93 m, 39.31°N 3.26°W, 22 Jun. 2022, IEOCD-MEDTIS22/301; Balearic Islands, ♂ 14.5×15.5 mm, CANAL0209 stn 18, IEOCD-PISA/3005; Menorca, Maó, ovig ♀ 14.8×17.2 mm, MAO12 stn 38, IEOCD-PISA/3006; ♂ 7.1×8.2 mm, MAO12 stn 38, IEOCD-PISA/3007. Mediterranean Sea, ♂ 13.4×15.6 mm, ICMZ13865/2017.

Distribution. Mediterranean: from Alboran Sea to Levantine Sea (d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.).

Habitat. Mainly among Posidonia oceanica rhizomes (d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.), sand and muddy sand bottoms (García Raso 1984García Raso J.E. 1984. Brachyura of the coast of Southern Spain (Crustacea, Decapoda). Spixiana 7: 105-113.). Mainly between 4 and 40 m depth (Zariquiey Álvarez 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf ), sometimes up to 137 m (Lewinsohn and Holthuis 1986Lewinsohn C., Holthuis L.B. 1986. The Crustacea Decapoda of Cyprus. Zool. Verh. 230: 1-64. https://doi.org/10.1017/S1755267209990911 ).

Remarks. As Zariquiey Álvarez (1959)Zariquiey Álvarez R. 1959. Crustáceos Decápodos de la región de Cadaqués. II Parte. Misc. Zool. 1(2): 1-7. https://decapoda.nhm.org/pdfs/30246/30246.pdf noted, P. muscosa is closely related to P. hirticornis (referred to as P. corallina) and P. tetraodon, with a rostrum that is more similar to that of P. hirticornis. P. muscosa has a single setiferous tubercle in the posterobranchial part, not two as in P. tetraodon and P hirticornis, although in the latter species the external one is sometimes very small. Hepatic spines are very small or even absent in P. muscosa; if they are present, they are always smaller than the external orbital ones, while in the other two species they are well developed and larger than the external orbital spines. Moreover, P. hirticornis and P. tetraodon have three well-differentiated laterobranchial spines, while in P. muscosa their development is more variable, being somewhat lobed, especially the anterior one (see Fig. 151c in Zariquiey Álvarez, 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf ).

Maia nodipes (Leach, 1815Leach W.E. 1815. The Zoological Miscellany; Being Descriptions of New, or Interesting Animals. R.P. Nodder, London 2: 1-154, pls: 61-120. https://www.biodiversitylibrary.org/page/28685302 ) (superseded combination).

Inachus musivus Otto, 1821Otto A.G. 1821. Conspectus animalium quorundam maritimorum nondum editorum pars prior quam patri dilectissimo ad cineres usque venerando Bernhardo Crristiano [sic] Otto philosophiae et medicinae doctori, hujusque quondam in universitate Francofurtensi professori publico ordinario, nunc professori honorario et emerito, societatis patrioticae Silesiacae et Marchicae, physiographicae Lundensis, naturae scrutatorum Berolinensis et Halensis, nec non physicae elangensis membro etc: 1-20. Typis Universitatis, Vratislaviae. https://www.marinespecies.org/aphia.php?p=sourcedetails&id=106579 (junior subjective synonym).

Material examined. Spain, Cádiz, Castillo de Santa Catalina, ♂ 20×23.5 mm, 36.53°N 6.31°W, 1 Aug. 2015, IEOCD-PISA/3009; ♂ 16.8×18.4 mm, IEOCD-PISA/3033; Cádiz, Castillo de San Sebastián, indet, 36.52°N 6.31°W, IEOCD-PISA/3032; ♀ 14.9×17.5 mm, IEOCD-PISA/3034; Málaga, Cabopino, ♂ 13.8×15.7 mm, 36.50°N 4.63°W, 18 May 2005, IEOCD-PISA/3008; Menorca, Maó, ♂ 9.7×10.1 mm, 72 m, 39.82°N 4.37°E, 29 Jan. 2014, ICMD000865. Portugal, Madeira, Funchal Bay, ♀ 17.7×21.9 mm, 1 May 1959, MMF 15797; Funchal fish market, ♂ 21.3×22.6 mm, 27 Jul. 1956, MMF 8838.

Distribution. Eastern Atlantic: from the English Channel and France to Mauritania (d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.), including Madeira (Fransen 1991Fransen C.H.J.M. 1991. Preliminary report on Crustacea collected in the eastern part of the North Atlantic during the Cancap and Mauritania expeditions of the former Rijksmuseum van Natuurlike Historie, Leiden. Nationaal Natuurhistorisch Museum, Leiden: i-vi + 1-200.) and the Canary (González 2016González J.A. 2016. Brachyuran crabs (Crustacea: Decapoda) from the Canary Islands (eastern Atlantic): checklist, zoogeographic considerations and conservation. Sci. Mar. 80: 89-102. https://doi.org/10.3989/scimar.04350.10A ) and Cape Verde islands (González et al. 2017González J.A., Triay-Portella R., Martins A., et al. 2017. Checklist of brachyuran crabs (Crustacea: Decapoda) from the Cape Verde Islands, with a biogeographic comparison with the Canary Islands (Eastern Atlantic). Cah. Biol. Mar. 58: 137-151. https://doi.org/10.21411/CBM.A.6C592127 , González 2018González J.A. 2018. Checklists of Crustacea Decapoda from the Canary and Cape Verde Islands, with an assessment of Macaronesian and Cape Verde biogeographic marine ecoregions. Zootaxa 4413: 401-448. https://doi.org/10.11646/zootaxa.4413.3.1 ). Mediterranean: many records from both western and eastern basins (d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.).

Habitat. On rocky bottoms, often with significant animal concretion; rhizomes of Posidonia (d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.); coralligenous bottoms; coarse sand bottoms under the influence of the current (Ledoyer 1968Ledoyer M. 1968. Écologie de la faune vagile des biotopes méditerranéens accessibles en scaphandre autonome (région de Marseille principalement). IV. Synthèse de l’étude écologique. Recl. Trav. Stat. Mar. Endoume 44(60): 126-295. https://decapoda.nhm.org/pdfs/29777/29777.pdf ), detrital bottoms (Števčić 1990Števčić Z. 1990. Checklist of the Adriatic Decapod Crustacea. Acta Adriat. 31(1-2): 183-274. https://decapoda.nhm.org/pdfs/22976/22976.pdf ). From the intertidal zone (Livory 1997Livory A. 1997. Crabes de la Manche: le point des connaissances. L’Argiope, 18-19 (automne 1997-hiver 1998): 18-64.) up to 100 m depth (Števčić 1990Števčić Z. 1990. Checklist of the Adriatic Decapod Crustacea. Acta Adriat. 31(1-2): 183-274. https://decapoda.nhm.org/pdfs/22976/22976.pdf ).

Remarks. P. nodipes is morphologically and molecularly closely related to P. armata), but both species can be easily differentiated by the shape of the intestinal tubercle-spine, which is a blunt spine in P. nodipes but an acute spine in P. armata. However, in order to see it, one must “remove” the dense, short, pile-like setae that exist in this carapace area. P. nodipes also has a more developed hepatic spine and two deep sulcs in the third thoracic sternite (absent in P. armata).

Cancer tetraodon Pennant, 1777Pennant T. 1777. British Zoology, vol. IV. Crustacea. Mollusca. Testacea. London: I-viii, 1-154, pl. 1-93. https://www.biodiversitylibrary.org/item/127011#page/5/mode/1up (superseded combination).

Arctopsis tetraodon Pennant, 1777Pennant T. 1777. British Zoology, vol. IV. Crustacea. Mollusca. Testacea. London: I-viii, 1-154, pl. 1-93. https://www.biodiversitylibrary.org/item/127011#page/5/mode/1up (generic name supressed).

Cancer hircus Fabricius, 1781Fabricius J.C. 1781. Species insectorum exhibentes eorum differentias specificas, synonyma, auctorum, loca natalia, metamorphosin adiectis observationibus, descriptionibus. Tome I. Hamburgi et Kilonii: Carol Ernest Bohnii. i-viii + 552 pp. https://doi.org/10.5962/bhl.title.36509 (junior subjective synonym).

Cancer praedo Herbst, 1796Herbst J.F.W. 1791-1796. Versuch einer Naturgeschichte der Krabben und Krebse nebst einer systematischen Beschreibung ihrer verschiedenen Arten. Zweyter Band. Mit XXV Kupfer-Tafeln und Register. Krebse. Gottlieb August Lange, Berlin und Stralsund, viii + 225 + [1] pp. 25 pls. https://doi.org/10.5962/bhl.title.64679 (junior subjective synonym).

Inachus tomentosus Rafinesque, 1814Rafinesque C.S. 1814. Précis des découvertes et travaux somiologiques de Mr. C.S. Rafinesque-Schmaltz entre 1800 et 1814; ou choix raisonné de ses principales découvertes en zoologie et en botanique, pour servir d’introduction à ses ouvrages futurs. Palerme. 1-55. http://www.biodiversitylibrary.org/item/27701 https://doi.org/10.5962/bhl.title.6135 (junior subjective synonym).

Pisa convexa Brandt, 1880Brandt A.T. 1880. Über mediterrane Crustaceen aus den Gattungen: Stenorhynchus, Achaeus, Inachus, Herbstia und Pisa, unter Benutzung von Materialien des Dr. R. A. Philippi. Bull. Acad. Imp. Sci. St-Pétersbourg 26: 395-420. (junior subjective synonym).

Pisa quadricornis Brandt, 1880Brandt A.T. 1880. Über mediterrane Crustaceen aus den Gattungen: Stenorhynchus, Achaeus, Inachus, Herbstia und Pisa, unter Benutzung von Materialien des Dr. R. A. Philippi. Bull. Acad. Imp. Sci. St-Pétersbourg 26: 395-420. (junior subjective synonym).

Materiale examined. Spain, Cádiz, Rota, ♂ 21.3×21.5 mm, 36.61°N 6.36°W, 20 Apr. 2012, IEOCD-PISA/3016; Cádiz, El Chato, ♂ 22.5×23.1 mm, 36.47°N 6.26°W, 1 Sep. 2009, IEOCD-PISA/3010; Cádiz, Sancti Petri, ♂ 6.6×6.8 mm, 15 Jan. 1996, ICM; Cádiz, Castillo de San Sebastián, ♂ 25.1×28 mm, 36.52°N 6.31°W, IEOCD-PISA/3012; Cádiz, Castillo de Santa Catalina, ♀ 21.1×22 mm, 36.53°N 6.31°W, 15 Jun. 2015, IEOCD-PISA/3011; LOCALIDAD ovig ♀ 25.8×25.2 mm, ovig ♀ 26.6×28.8 mm, ovig ♀ 26.7×27.6 mm, ovig ♀ 22.3×22.9 mm, ♂ 19.8×20.1 mm, ♂ 17.7×18.7 mm, 20 Feb. 2015, IEOCD-PISA/3013; Cantabria, Playa de Oyambre, ♂ 13.2×14.1 mm, 43.39°N 4.33°W, IEOCD-PISA/3014; Canary Islands, Santa Cruz de Tenerife, juv ♂ 6.3×6.7 mm, 28.46°N 16.24°W, Sep. 1986, IEOCD-PISA/3035; 2 indet, 6.4×6.2 m, 1 Sep. 1986, IEOCD-PISA/3036; ♂ 13.9×15.9 mm, 1 Sep. 1986, IEOCD-PISA/3037; Alicante, Calpe, indet, 18 Sep. 2015; Granada, La Herradura, ♂ 20.8×20.1 mm, 3-4 m, 36.75°N 3.77°W, 28 Oct. 2006, IEOCD-PISA/3038. Portugal, Madeira, Funchal Bay, ♀ 19×19.9 mm, 18 Nov. 1964, MMF 23458; Madeira, Caniçal, Baía d’Abra, ♂ 32.6×32.2 mm, 22 Jul. 1979, MMF 23312.

Distribution. Eastern Atlantic: from the Isle of Man, west of Ireland and English Channel to Mauritania (d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.), including the Canary Islands (González 2016González J.A. 2016. Brachyuran crabs (Crustacea: Decapoda) from the Canary Islands (eastern Atlantic): checklist, zoogeographic considerations and conservation. Sci. Mar. 80: 89-102. https://doi.org/10.3989/scimar.04350.10A , 2018González J.A. 2018. Checklists of Crustacea Decapoda from the Canary and Cape Verde Islands, with an assessment of Macaronesian and Cape Verde biogeographic marine ecoregions. Zootaxa 4413: 401-448. https://doi.org/10.11646/zootaxa.4413.3.1 ). Mediterranean: many records from both western and eastern basins (d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.).

Habitat. On Posidonia oceanica bottoms (Zariquiey Álvarez 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf ), rocky bottoms, rocky bottoms with algae, sand bottoms with rocks (García Raso 1984García Raso J.E. 1984. Brachyura of the coast of Southern Spain (Crustacea, Decapoda). Spixiana 7: 105-113.), sometimes associated with Cystoseira spp. or intertidal (Livory 1997Livory A. 1997. Crabes de la Manche: le point des connaissances. L’Argiope, 18-19 (automne 1997-hiver 1998): 18-64., d’Udekem d’Acoz 1999d’Udekem d’Acoz C. 1999. Inventaire et distribution des crustacés décapodes de l’Atlantique nordoriental, de la Méditerranée et des eaux continentales adjacentes au nord de 25°N. Collection Patrimoines Naturels 40: i-x + 1-383.). From 3 to 100 m depth (Zariquiey Álvarez 1968Zariquiey Álvarez R. 1968. Crustáceos decápodos ibéricos. Inv. Pesq. 32: i-xv + 1-510. https://decapoda.nhm.org/pdfs/10992/10992.pdf , Noël 2016Noël P. 2016. La pise tétraodon Pisa tetraodon (Pennant, 1777). In Muséum national d’Histoire naturelle [ed], 22 mai 2016. Inventaire natn. Patrimoine Nat.: 1-13. http://inpn.mnhn.fr , this work).

Remarks. Pisa tetraodon is the most common species within the genus Pisa and is found on shallow bottoms of rocks, algae and seagrasses. For comparative morphological comments, see the above observations on P. hirticornis and P. muscosa.

IDENTIFICATION KEY TO EASTERN ATLANTIC AND MEDITERRANEAN SPECIES OF PISINAE (EPIALTIDAE)

DISCUSSION AND CONCLUSIONS

Three of the species described as belonging to the genus Pisa, P. calva, P. carinimana and P. sanctaehelenae, share several morphological characteristics, which differentiate them from the other Pisa species and allow us to separate them into a new genus, Afropisa. The molecular analysis conducted on A. carinimana n. comb. confirms its distinctiveness from the genus Pisa. The genetic distance observed in the mitochondrial sequences, as shown in Figs 2-4Figs 2, 3, 4, further supports its separation from Pisa and suggests a closer relationship with Micropisa.

Additionally, Stimpson (1857Stimpson W. 1857. Prodromus descriptionis animalium evertebratorum, quae in Expeditione ad Oceanum Pacificum Septentrionalem, a Republica Federata missa, Cadwaladaro Ringgold et Johanne Rodgers Ducibus, observavit et descripsit W. Stimpson. Pars III. Crustacea Majoidea. Proc. Acad. Nat. Sci. Philadelphia 9: 216-221. https://doi.org/10.5962/bhl.title.51447 , in Monod 1956Monod T. 1956. Hippidea et Brachyura ouest-africains. Mem. IFAN 45: 1-674, 884 Figs) pointed out that there was a generic difference in the third maxilliped, whose merus would be without a notch for the reception of the carpus in Micropisa but with a notch in Pisa, and he also mentioned that Pisa carinimana, which cannot be separated from Pisa, does not have the notch. Afropisa carinimana n. comb. does not have a well-differentiated lobe on the merus of the third maxilliped at the level of the carpal insertion (Fig. 7A1, Monod 1956: Figs 658-661Monod T. 1956. Hippidea et Brachyura ouest-africains. Mem. IFAN 45: 1-674, 884 Figs), as may be observed in Pisa (Figs 7A2, 7A3). This lobe is also absent in A. sanctaehelenae n. comb. (Chace 1966: Fig. 14cChace F.A. Jr. 1966. Decapod crustaceans from St. Helena Island, South Atlantic. Proc. U.S. Natl. Mus 118: 623-661, pls. 1-2. https://doi.org/10.5479/si.00963801.118-3536.623 ), A. calva n. comb. (Forest and Guinot 1966: Fig. 11cForest J., Guinot D. 1966. Crustacés Décapodes: Brachyoures. In: Campagne de la Calypso dans le Golfe de Guinée et aux îles Príncipe, São Tomé, et Annobon (1956). Résultats scientifiques des Campagnes de la ‘Calypso’. Fascicule VII. 16. Ann. Institut Océanogr. 44: 23-124.) and Micropisa ovata Stimpson, 1857Stimpson W. 1857. Prodromus descriptionis animalium evertebratorum, quae in Expeditione ad Oceanum Pacificum Septentrionalem, a Republica Federata missa, Cadwaladaro Ringgold et Johanne Rodgers Ducibus, observavit et descripsit W. Stimpson. Pars III. Crustacea Majoidea. Proc. Acad. Nat. Sci. Philadelphia 9: 216-221. https://doi.org/10.5962/bhl.title.51447 (Monod 1956: Fig. 674Monod T. 1956. Hippidea et Brachyura ouest-africains. Mem. IFAN 45: 1-674, 884 Figs).

The rostral spines remain close together until near the tip in Pisa, while they are totally joined at the base and diverge very basally in Afropisa n. gen. The basal antennal segment has a single tubercle-shape tooth on the lower-outer margin (somewhat more developed and prominent in P. muscosa), whereas the Afropisa n. gen. has a vertically elongated tooth. On this same segment, Pisa species possess a small antero-outer tooth that is not visible from a dorsal view of the specimen while, for Afropisa, this tooth is elongated and visible from a dorsal view. For P. muscosa this tooth is like that of A. carinimana n. comb. but is not visible because of its position behind the rostral spines.

All species in the genus Pisa sensu stricto share the presence of a pair of tubercles in the pterygostomial region. In contrast, Afropisa n. gen. typically has three tubercles in this region. The new genus also lacks well-defined tubercles on the protogastric area (except in A. calva n. comb.) in contrast to Pisa.

The morphology of the first gonopod is also a distinguishing feature between these two genera. In addition, it is worth noting that the adults of the three species included in the new genus are relatively small.

However, further molecular analyses of A. calva n. comb. and A. sanctaehelenae n. comb. should be conducted in the near future to confirm their new taxonomic status through integrative taxonomy.

After conducting a comprehensive morphological study of Lissa chiragra specimens, reviewing relevant literature on this species, performing genetic analyses and considering the conclusions from a morphological description of its larvae by Guerao et al. (2003)Guerao G., Rufino M., Abelló P. 2003. Morphology of the larval and first juvenile stages of the spider crab Lissa chiragra (Brachyura: Majidae: Pisinae). J. Nat. Hist. 37: 647-671. https://doi.org/10.1080/00222930110116048 , it is concluded that L. chiragra should be reclassified under the genus Pisa. As Lissa is a monotypic genus, it is appropriate to synonymize it under the genus Pisa. Both morphological and molecular evidence suggest that P. chiragra is more closely related to P. armata and P. nodipes than to other species within the genus Pisa. Therefore, incorporating P. chiragra into the genus Pisa is supported by both morphological and molecular similarities.

Also based on morphological and molecular analyses, P. hirticornis is considered a good species that is closely related to P. tetraodon. While these species share many morphological characteristics, the length and point of divergence of the rostral spines serve as a stable morphological character to differentiate them. Other morphological and molecular evidence supports the distinction between P. hirticornis and P. tetraodon, further confirming their separate species status.