Scorpaena decemradiata new species (Teleostei: Scorpaenidae) from the Gulf of Aqaba, northern Red Sea, a species distinct from Scorpaena porcus ; Scorpaena decemradiata nueva especie (Teleostei: Scorpaenidae) del golfo de Aqaba, mar Rojo del norte, una especie distinta de Scorpaena porcus

1 Im Ramstal 76, 97922 Lauda-Königshofen, Germany. (RF) (Corresponding author) E-mail: ronfricke@web.de. ORCID iD: http://orcid.org/0000-0003-1476-6990 2 National Natural History Collections and Department of Ecology, Evolution and Behavior, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel. (DG) E-mail: dani.golani@mail.huji.ac.il. ORCID iD: http://orcid.org/0000-0003-4575-3324 3 The Hebrew University of Jerusalem, 91905 Jerusalem, Israel. (BA-G) E-mail: brendag@savion.huji.ac.il. ORCID iD: http://orcid.org/0000-0002-3237-6980 4 Senckenberg Biodiversität und Klima Forschungszentrum, Arbeitsgruppe Biogeografie, Senckenberganlage 25, 60325 Frankfurt am Main, Germany. 5 Senckenberg Forschungsinstitut und Naturmuseum, Sektion Ichthyologie, Senckenberganlage 25, 60325 Frankfurt am Main, Germany. (UZ) E-mail: uzajonz@senckenberg.de. ORCID iD: https://orcid.org/0000-0001-6106-1411


INTRODUCTION
The scorpionfishes of the genus Scorpaena Linnaeus, 1758 are mostly distributed in warm temperate seas, and occasionally also in tropical seas, around the world. They inhabit benthic habitats, mostly dwelling on rocky reefs. The genus includes a total of 61 valid species . It is characterized within the family Scorpaenidae by the dorsal rays normally XII,[9][10]8 or 10 normal for some species), anal rays normally III, 5; pectoral rays 16-21, some rays branched, the branching usually compound in larger specimens; swimbladder absent; vertebrae 24; scales on body cycloid or ctenoid; occipital pit usually present, never flat or convex; palatine teeth present; ventral margin of lacrimal bone usually with numerous spines; posterior lacrimal spine absent or not hooked forward; no slit behind fourth gill arch; scales on pectoral fin base reduced or absent; lateral line normal, continuing onto or near base of caudal fin; pored lateral-line scales forming relatively complete tubes; and peritoneum pale (Eschmeyer 1969;Poss 1999;modified).
The genus Scorpaena has been known since ancient times (Aristotle, 4 th century BC; see Artedi 1738b); in modern ichthyology it was first described by Linnaeus (1758: 266), with S. porcus Linnaeus, 1758 andS. scrofa Linnaeus, 1758 as the only known species at the time. The species description of S. porcus by Linnaeus (1758) was based on multiple sources from localities in the Mediterranean Sea (see Artedi 1738b, "Scorpaena pinnulis, ad oculos et nares"), and it was subsequently designated by Bleeker (1876: 3) as the type species. The genus has been placed on the Official List of Generic Names in Zoology by Opinion 77 (Anonymous 1922).
When examining specimens of Scorpaena from the Gulf of Aqaba, our attention was drawn to the identity of specimens previously misidentified as Scorpaena porcus. We found these specimens to be distinct from populations in the Mediterranean Sea, prompting our examination of other previous records of S. porcus, allegedly from the Red Sea. The analysis of these individuals demonstrated that the Gulf of Aqaba population represents a separate species, which is described in the present paper.

Diagnosis.
A species of Scorpaena with dorsal fin spines XII, soft dorsal fin rays 10 (the last divided at base); pectoral fin rays 16, uppermost branched pectoral fin ray is the second; lacrimal with 2 spines over maxilla that point at nearly right angle from each other, the posterior pointing ventrally and slightly anteriorly; occipital pit well developed; anteriormost mandibular lateral-line pores small, separated; scales ctenoid; 59-62 scale rows in longitudinal series; scales absent on chest and pectoral fin base; and cirri developed over entire head and body, but no cirri on lower jaw.

Colour in alcohol.
For pigmentation of body refer to Figure 1, which is part of the description.
Head and body reddish brown, back with five indistinct darker saddles that continue irregularly across the upper two-thirds of the body. Head reddish brown; eye dark grey. Pectoral fin base and belly white. Dorsal fin marbled with brown, without a black blotch. Pectoral fins pale, with series of dark brown spots in their upper two-thirds. Pelvic fins pale. Anal fin light brown, with a central and a distal posterior bar of dark brown spots. Caudal fin whitish, with a basal, a central and a distal vertical dark brown bar.
Etymology. Decem (Latin) means ten; radiata (Latin) means rayed. The name refers to the ten soft rays in the dorsal fin of the new species, which clearly distinguish it from the closely related species, S. porcus.
Distribution and habitat. Known only from the Gulf of Aqaba (Eilat, Israel) (Fig. 2). The depth of collection and the habitat are unknown. Comparisons. Scorpaena decemradiata n. sp. is very similar to S. porcus from the Mediterranean Sea and eastern Atlantic; these two species are distinguished from other congeners by the following combination of characters: presence of a deep occipital pit, pectoral fin base naked, lateral-line pores immediately posterior to symphysis of lower jaw widely separate, and more than 56 scale rows in longitudinal series. The new species is distinguished from S. porcus (see Table  2) by 10 dorsal fin soft rays (versus 7-9 in S. porcus), scales on body ctenoid (versus emarginate), and uppermost branched pectoral fin ray is the second (versus usually third, rarely second to fourth).
An identification key to the species of Scorpaena in the eastern Atlantic, Mediterranean and Red Sea is presented below, in order to easily identify this species.
In the Red Sea, the new species might be confused with Parascorpaena aurita (Rüppell, 1829), which among other characters, however, only has 8-9 dorsal fin soft rays (versus 10 in Scorpaena decemradiata n. sp.), and larger scales, with only 35-44 scale rows in longitudinal series (versus 59-62 in Scorpaena decemradiata n. sp.). Linnaeus, 1758 (Figs 3-4,  Diagnosis. A species of Scorpaena with dorsal fin spines XII, soft dorsal fin rays 7-9 (the last divided at base); pectoral fin rays 16-18, uppermost branched pectoral fin ray is usually the third (rarely second to fourth); lacrimal with usually 2 spines over maxilla that point at nearly right angle from each other, the posterior pointing ventrally and slightly anteriorly; occipital   (Fig. 2). The species dwells benthic habitats, from shallow water to 800m depth, in the shallows usually on rocks covered with algae.

DISCUSSION
Scorpaena erythraea was originally described by Cuvier in Cuvier and Valenciennes (1829: 316), based on three specimens collected by Étienne Geoffroy Saint-Hilaire in Egypt. Geoffroy Saint-Hilaire's fish material was collected during the French expedition to Egypt in 1798-1799; in 1799, the material was transported to Alexandria, Egypt, and when Alexandria was conquered by British troops, Geoffroy Saint-Hilaire refused to hand over the materials and documents to the British General Hutchinson, and later sent the material to Paris (Bauchot et al. 1990: 88). The specimens were neither described nor illustrated in the works of Étienne and Isidore Geoffroy Saint-Hilaire (1802a, 1802b, 1809, 1817, 1827a, 1827b. The species was subsequently reported by several authors based on Cuvier in Cuvier and Valenciennes (1829); only Günther (1860: 116) described an additional specimen from the Red Sea (BMNH 1871.4.13.26). This specimen, as well as another specimen identified   Eschmeyer and Dempster (1990: 674-675) were the first authors to discuss the identity of S. erythraea; they noticed that the species was probably identical with S. porcus Linnaeus 1758, and supposed that the type locality of S. erythraea was incorrect and the species was rather collected on the Mediterranean Sea shore of Egypt. This suspicion was followed by subsequent authors. Golani and Bogorodsky (2010: 65) treated the Red Sea record of S. porcus as incorrect, and suggested that it was based on misidentifications. A confusion of the localities of material collected by Geoffroy Saint-Hilaire is highly likely, as the material was apparently not labelled originally, but subsequently after it arrived at Paris. There were just three major collecting localities of that expedition, the Nile, the Mediterranean Sea at Alexandria, and the Red Sea coast of Egypt. As-signing the locality was straightforward for freshwater fishes, and not a problem for material with manuscript notes by Geoffroy Saint-Hilaire, which could be easily identified, but for the other material which was not mentioned by Geoffroy Saint-Hilaire, the locality had to be guessed. The present study confirms the identity of the syntypes of Scorpaena erythraea Cuvier in Cuvier and Valenciennes, 1829 as conspecific with Scorpaena porcus Linnaeus, 1758, and the highly probable confusion of the type locality. All the characters examined agree well with eastern Mediterranean populations of S. porcus (see Table 3). The syntypes of S. erythraea (MNHN 0000-6706) were most probably collected near Alexandria, Egypt. The larger specimen (154.7 mm SL; Fig. 4, Table 2) of MNHN 0000-6706 is hereby designated as the lectotype of Scorpaena erythraea Cuvier in Cuvier and Valenciennes, 1829.
While we thus conclude that Scorpaena erythraea is a junior synonym of S. porcus and based on Mediterranean material, another specimen allegedly originating from the Gulf of Aqaba, Red Sea, SMNHTAU 2578,  BMNH 1938.11.15. 50 (1), BMNH 1960. 6.24.145-149 (5), BMNH 1963 (1) Frøiland (1972: 25), and then again referred to as Scorpaenopsis erythraea (see Frøiland 1972: 72). The former is a manuscript name that was supposed to be published but never was as the manuscript was first submitted to and then withdrawn from the journal Senckenbergiana biologica. However, the specimen also clearly belongs to S. porcus, and the locality is most probably in error, i.e. the specimen probably originated from the Mediterranean coast of Israel. Frøiland (1972: 23) also recorded Scorpaena porcus (non Linnaeus, 1758) from Eilat, Israel, based on two specimens numbered HUJ 2418; these are the only specimens that were really collected in the Red Sea and belong to the Scorpaena porcus complex, but were found to represent S. decemradiata n. sp., which is described in the present paper.
Summarizing these results, Scorpaena porcus was previously thought to be a case of anti-Lessepsian migration, but is obviously restricted to the eastern Atlantic and Mediterranean, and previous records from the Red Sea were based on material with incorrect localities or misidentifications. The Red Sea (Gulf of Aqaba) is inhabited by the closely related species S. decemradiata n. sp. This species has not yet been recorded from Jordan (Khalaf and Zajonz 2007).
An updated checklist of the species of the genus Scorpaena is presented here (Appendix 1). It now includes a total of 62 valid species. Most species are known from the eastern Atlantic, including the Mediterranean (18 species, which is 29.0% of the total species of the genus; 15 species or 24.2% are endemic to the region), followed by the eastern Pacific (14 species, 22.6%, all endemic) and the western Atlantic (14 species, 22.6%, with 12 species endemic, 19.4%), the western Pacific (12 species, 19.4%; 8 endemic, 12.9%), the eastern Indian Ocean (5 species, 8.1%; 2 endemic, 3.2%), the central Pacific (3 species, 4.8%; all endemic), the Red Sea (1 endemic species, 1.6%), and the western Indian Ocean (1 species, 1.6%; none endemic). From the Red Sea, S. decemradiata n. sp. is the only known species of this genus; it is probably endemic to the northern Red Sea, because it is not present in the German deep-sea expeditions to the central Red Sea, MESEDA I-III and MINDIK (Türkay 1996; fish identifications and an unpublished faunal account by Uwe Zajonz).
As only two specimens of Scorpaena decemradiata n. sp. are known, little can be said about intraspecific variation. The intraspecific variation between specimens of S. porcus in the central Mediterranean Sea and the Black Sea was examined by Manilo and Peskov (2016), who found some significant differences for some length proportions between specimens in the two regions. Boissin et al. (2016) examined the population genetics of this species, and also found a weak genetic differentiation between populations in the Black Sea and the Mediterranean Sea. In the present study, western and eastern Mediterranean populations of S. porcus are compared (see Table 3), with no significant differences in fin-ray counts and scales, but again some dif-ferences in length proportions. We could not determine whether there are clines or rather a strict separation between the populations, but doubt that these differences are of taxonomic significance.
The restricted range of Scorpaena decemradiata n. sp. may be a relict distribution; the Scorpaena porcus complex that prefers a warm temperate climate may have had a wider distribution range during glacial periods, possibly all around the African continent, like S. scrofa. In this scenario, the S. porcus complex retreated to the north on both sides of the continent when the sea temperatures became warmer, but only on the western side was there room to spread out, while on the eastern side it was limited to the northernmost extent of the Red Sea in the Gulf of Aqaba. The subsequent continental barrier then facilitated speciation in this group, resulting in two different species on the western and eastern sides of the continent.

Key to eastern Atlantic, Mediterranean and Red Sea species of the genus Scorpaena
Remark. This key is based on Poss (2016), but updated and expanded to cover the Red Sea species.