Superorder CAENOGASTROPODA Cox, 1960
Superfamily RISSOOIDEA Gray, 1847
Family RISSOIDAE Gray, 1847
Genus Alvania Risso, 1826

Type species: Alvania europea Risso 1826: 142, pl. 9, Fig. 116 = Alvania cimex (Linnaeus, 1758) (Turbo), by subsequent designation Nevill 1885: 105.

Alvania amatii Oliverio, 1986
(Fig. 2A, B)

Alvania amatii Oliverio, 1986

Mean dimensions (1 specimen and 3 shells): 2.02 (±0.22) × 1.23 (±0.08) – 1.42 (±0.12) mm [1.5 × 1.0 – 1.1 mm; 2.6 × 1.4 – 1.7 mm].

Remarks. Alvania amatii is characterized by its smaller shell dimensions and paucispiral protoconch having 5 spiral threads.

Distribution. The species seems to be an eastern Mediterranean endemic (Oliverio 1986, van Aartsen et al. 1989). Turkish coasts: Aegean Sea (Oliverio 1986, van Aartsen and Kinzelbach 1990) and Levantine Sea (Buzzurro and Greppi 1996, Bitlis Bakır et al. 2012).

Alvania aspera (Philippi, 1844)
(Fig. 2C, D)

Rissoa aspera Philippi, 1844

Mean dimensions (9 specimens and 1 shell): 1.54 (±0.32) × 1.14 (±0.15) – 1.11 (±0.20) mm [0.7 × 0.6 – 0.6 mm; 3.7 × 2.1 – 2.4 mm].

Remarks. The medium-sized and strong shell, thick axial ribs wider than interspaces on the last whorl and paucispiral protoconch are some of the evident diagnostic features of A. aspera.

Distribution. A. aspera is an eastern Mediterranean endemic (Bogi et al. 1989, Barash and Danin 1992, Zenetos and van Aartsen 1995). Turkish coasts: Levantine and Aegean coasts (Demir 2003, Öztürk et al. 2008).

Alvania beanii (Hanley in Thorpe, 1844)
(Figs 2E, F, 3D, E, 7K)

Cingula beanie Hanley in Thorpe, 1844

Mean dimensions (39 specimens and 11 shells): 2.83 (±0.12) × 1.62 (±0.05) – 1.86 (±0.07) mm [2.8 × 1.6 – 1.9 mm; 3.9 × 2.1 – 2.4 mm].

Remarks. A. beanii has a multispiral protoconch. It differs from the similar A. hispidula in its greater number of spiral cords on the penultimate and last whorls of the teleoconch.

Distribution. Arctic Ocean (Hudenbick and Warén 1969), northeast Atlantic Ocean and Mediterranean Sea (Oliverio et al. 1986, Scaperrotta et al. 2011). Turkish coasts: Aegean Sea (Demir 2003), Sea of Marmara (Ostroumoff 1894, 1896) and Levantine Sea (Bitlis Bakır and Öztürk 2016).

Alvania bozcaadensis Tisselli and Giunchi, 2013
(Fig. 2. G, H)

Alvania bozcaadensis Tisselli and Giunchi, 2013

Dimensions of two specimens: 1.8 × 1.2 – 1.3, 1.0 × 0.8 – 0.9 mm.

Remarks. The species can be confused with A. lanciae (Calcara, 1845) and with the juveniles of A. discors, but A. bozcaadensis has no microsculpture on the surface of its protoconch and teleoconch, whereas A. lanciae bears microsculpture on both its protoconch and teleoconch. It differs from A. discors because the protoconch of the later species has a multispiral protoconch, while A. bozcaadensis has a blunt paucispiral apex and fewer axial ribs on the last whorl.

Distribution. Turkish coasts: Levantine and Aegean coasts (Tisselli and Giunchi 2013).

Alvania cancellata (da Costa, 1778)
(Fig. 2I, J)

Turbo cancellatus da Costa, 1778

Mean dimensions (26 specimens and 5 shells): 3.59 (±0.17) × 2.39 (±0.09) – 2.57 (±0.11) mm [0.9 × 0.8 – 0.7 mm; 4.9 × 3.3 – 3.5 mm].

Remarks. Alvania cancellata is one of the most common and characteristic species of the genus, because of its typical shell structure, large nodule on the base of the columella and multispiral protoconch.

Distribution. Northeast Atlantic Ocean and Mediterranean Sea (Fretter and Graham 1978, Gofas 2007). Turkish coasts: Levantine and Aegean coasts (Demir 2003), Sea of Marmara (Ostroumoff 1894, 1896, Aslan-Cihangir and Ovalis 2013).

Alvania carinata (da Costa, 1778)
(Fig. 2K, L)

Turbo carinatus da Costa, 1778

Dimensions of two specimens: 2.9 × 1.9 – 2.2, 3.4 × 2.4 – 2.6 mm.

Remarks. Alvania carinata can be easily distinguished by the strong spiral sculpture of its teleoconch and paucispiral protoconch.

Distribution. Arctic Ocean (Hudenbick and Warén 1969), northeast Atlantic Ocean and Mediterranean Sea (van Aartsen 1982b). Turkish coasts: Levantine and Aegean coasts (Demir 2003).

Alvania cimex (Linnaeus, 1758)
(Fig. 4A, B)

Turbo cimex Linnaeus, 1758

Mean dimensions (31 specimens and 35 shells): 3.44 (±0.15) × 2.37 (±0.06) – 2.58 (±0.09) mm [1.4 × 1.3 – 1.2 mm; 5.7 × 3.4 – 4.0 mm].

Remarks. A. cimex is quite similar to A. mamillata, but they differ in the number of whorls of their protoconchs. The protoconch of Alvania cimex consists of 2-2.3 whorls, compared with about 1.3 whorls in A. mamillata. However, the protoconch figure given by Gianuzzi-Savelli et al. (1997: 100, fig. 395a) for A. cimex does not seem to belong to this species.

It is stated that the number of protoconch whorls was used as a discriminating feature of the shells, but according to some studies (Oliver et al. 2015, Criscione et al. 2016) the protoconch features do not suffice for correct identification. Oliver et al. (2015) considered that A. cimex and A. mamillata may be the same species because they have the same distribution, habitats and colour patterns, except for the larval life span. Similarly, Criscione et al. (2016: Fig. 2) stated that the two species shared the same 16S and 28S sequences in the maximum-likelihood phylogram. In this study, we have considered the two species as different taxa, following the current WoRMS (2016) and CLEMAM (2016) databases. Future genetic studies on the larval development of these two species should clarify this aspect.

Distribution. Northeast Atlantic Ocean and Mediterranean Sea (Barash and Danin 1992). Turkish coasts: Levantine Sea (Buzzurro and Greppi 1996, Bitlis Bakır et al. 2012), Aegean Sea (Kocataş 1978), Sea of Marmara (Oberling 1969-1971) and Black Sea (Öztürk 1998).

Alvania cimicoides (Forbes, 1844)
(Fig. 4C, D)

Rissoa cimicoides Forbes, 1844

Mean dimensions (3 specimens and 11 shells): 2.32 (±0.21) × 1.46 (±0.10) – 1.57 (±0.12) mm [1.2 × 0.9 – 0.9 mm; 3.5 × 2.0 – 2.3 mm].

Remarks. This species is characterized by its dark brown–coloured and multispiral protoconch. It is distributed mostly at bathyal depths.

Distribution. Arctic Ocean (Hudenbick and Warén 1969), eastern Atlantic Ocean and Mediterranean Sea (van Aartsen 1982a, Gofas 2007). Turkish coasts: Aegean and Levantine coasts (Forbes 1844, Demir 2003), Sea of Marmara (Ostroumoff 1896, Aslan-Cihangir and Ovalis 2013) and Black Sea (Bacescu et al. 1971).

Alvania colossophilus Oberling, 1970
(Fig. 4E, F)

Alvania colossophilus Oberling, 1970

Dimension (one shell): 3.7 × 2.2 – 2.3 mm.

Remarks. A. colossophilus may be confused with A. lineata, but the first species differs in the sculpture of its paucispiral protoconch and the stronger and larger size of the shell.

Distribution. The species appears to be an eastern Mediterranean endemic (Bogi et al. 1989, Gianuzzi-Savelli et al. 1997). Turkish coasts: Levantine Sea (Buzzurro and Greppi 1996, Bitlis Bakır et al. 2012) and Aegean Sea (Okuş et al. 2006).

Alvania datchaensis Amati and Oliverio, 1987
(Fig. 4G, H)

Alvania datchaensis Amati and Oliverio, 1987

Mean dimensions (52 specimens and 17 shells): 2.23 (±0.05) × 1.31 (±0.02) – 1.53 (±0.03) mm [1.0 × 0.8 – 0.8 mm; 3.0 × 1.8 – 2.0 mm].

Remarks. It can be distinguished from the other similar Alvania species by the sculpture of its paucispiral protoconch with zigzag spiral lines, and the outer lip without labial varix.

Distribution. It is endemic to the eastern Mediterranean Sea (Cecalupo and Quadri 1996, Amati 2012). Turkish coasts: Levantine Sea (Buzzurro and Greppi 1996) and Aegean Sea (Amati and Oliverio 1987, van Aartsen and Kinzelbach 1990).

Alvania discors (Allan, 1818)
(Fig. 4I, J)

Turbo discors Allan, 1818

Mean dimensions (218 specimens and 82 shells): 3.12 (±0.09) × 1.97 (±0.03) – 2.13 (±0.05) mm [1.1 × 0.9 – 0.8 mm; 5.3 × 3.0 – 3.4 mm].

Remarks. The species is characterized by its polymorphic shell with a variable number of axial ribs (11-12) and spiral cords (8-9) on the last whorl. The protoconch is multispiral, and its shell may be completely brownish or with white bands.

Distribution. Northeast Atlantic Ocean and Mediterranean Sea (Barash and Danin 1992, Cecalupo and Quadri 1996). Turkish coasts: Levantine Sea (Buzzurro and Greppi 1996, Bitlis Bakır et al. 2012), Aegean Sea (Kocataş 1978) and Sea of Marmara (Oberling 1969-1971).

Alvania geryonia (Nardo, 1847)
(Figs 4K, L, 7J)

Rissoa geryonia Nardo, 1847

Mean dimensions (26 specimens and 24 shells): 3.29 (±0.10) × 1.91 (±0.04) – 2.27 (±0.06) mm [1.1 × 0.8 – 0.8 mm; 4.5 × 3.3 – 3.5 mm].

Remarks. Alvania geryonia can be misidentified with A. cimex, but the first one has more spirals on the penultimate whorl (5 spiral cords contrary to 3 spiral cords in A. cimex) and smaller granules on the teleoconch. The protoconch is multispiral.

Distribution. Northeast Atlantic Ocean and Mediterranean Sea (van Aartsen 1982a, Gofas et al. 2011). Turkish coasts: Levantine Sea (Demir 2003, Bitlis Bakır et al. 2012), Aegean Sea (Demir 2003, Çınar et al. 2012) and Sea of Marmara (Ostroumoff 1896, Demir 2003).

Alvania hispidula (Monterosato, 1884)
(Fig. 3A-C)

Acinus hispidulus Monterosato, 1884

The shell is solid with 4 convex teleoconch whorls and deep suture. Protoconch is multispiral. On the last whorl, above the aperture, there are 10-14 axial ribs, and 3 spiral cords on the last and penultimate whorls. There is a noteworthy distance between the first spiral cords and the suture. Thickened labrum and light brown coloured shell.

Mean dimensions (2 specimens and 4 shells): 3.42 (±0.09) × 1.72 (±0.10) – 2.19 (±0.06) mm [3.0 × 1.3 – 1.9 mm; 3.7 × 1.9 – 2.3 mm].

Remarks. Alvania hispidula is similar to A. beanii but differs in the number of spiral and axial ribs on the last whorl. Alvania beanii has a smaller shell and 6-7 spiral cords on the last whorl above the aperture, instead of 3 spirals in A. hispidula (4 in the penultimate whorl). The protoconch of A. hispidula (Fig. 3C) and A. beanii (Fig. 3D) are similar, but the protoconch of A. beanii has micro papillae.

Distribution. Atlantic Ocean and Mediterranean Sea (van Aartsen 1982a). Turkish coasts: Sea of Marmara (Ostroumoff 1896) and Aegean Sea (this study).

Alvania lactea (Michaud, 1832)
(Fig. 5A, B)

Rissoa lactea Michaud, 1832

Mean dimensions (11 specimens and 6 shells): 3.25 (±0.24) × 2.20 (±0.12) – 2.69 (±0.19) mm [1.2 × 1.1 – 1.1 mm; 4.8 × 3.0 – 3.8 mm].

Remarks. A. lactea differs markedly from the other species of the genus in its shell sculpture and large aperture. The protoconch is paucispiral.

Distribution. Arctic Ocean (Hudenbick and Warén 1969), North Atlantic Ocean and Mediterranean Sea (Barash and Danin 1992). Turkish coasts: Levantine Sea (Buzzurro and Greppi 1996, Bitlis Bakır et al. 2012), Aegean Sea (Demir 2003) and Sea of Marmara (Oberling 1960-1962, 1969-1971).

Alvania lineata Risso, 1826
(Fig. 5C, D)

Alvania costulosa Risso, 1826

Mean dimensions (4 specimens): 3.22 (±0.16) × 2.07 (±0.10) – 2.27 (±0.13) mm [2.8 × 1.9 – 2.0 mm; 3.6 × 2.3 – 2.6 mm].

Remarks. The species differs from the other species of the genus in its large paucispiral protoconch ornamented with spiral threads and in its strong shell, with its axial ribs as wide as the interspaces, with prominent spirals.

Distribution. Mediterranean Sea (Gofas et al. 2011). Turkish coasts: Aegean Sea (Kocataş 1978, Demir 2003), Levantine Sea (Demir 2003) and Dardanelles (Aslan-Cihangir and Ovalis 2013).

Alvania mamillata Risso, 1826
(Figs 5E, F, 6G, 7F-I)

Alvania mamillata Risso, 1826

Mean dimensions (32 specimens and 23 shells): 3.64 (±0.13) × 2.42 (±0.06) – 2.77 (±0.08) mm [1.4 × 1.2 – 1.1 mm; 4.9 × 3.2 – 3.7 mm].

Remarks. (See remarks for A. cimex). The paucispiral protoconch (about 1.3 whorls) and coarse granules on the teleoconch of A. mamillata are noteworthy features of the species.

Distribution. Northeast Atlantic Ocean and Mediterranean Sea (Zenetos and van Aartsen 1995). Turkish coasts: Levantine Sea (Bitlis Bakır et al. 2012) and Aegean Sea (van Aartsen and Kinzelbach 1990).

Alvania punctura (Montagu, 1803)
(Fig. 5G, H)

Turbo punctura Montagu, 1803

Mean dimensions (42 specimens and 24 shells): 1.78 (±0.05) × 1.06 (±0.02) – 1.21 (±0.02) mm [1.1 × 0.8 – 0.8 mm; 2.5 × 1.3 – 1.5 mm].

Remarks. It is recognizable by its multispiral protoconch and clathrate sculpture of the teleoconch.

Distribution. Arctic Ocean (Hudenbick and Warén 1969), Atlantic Ocean and Mediterranean Sea (van Aartsen 1982c, Gofas 2007). Turkish coasts: Aegean Sea (Demir 2003) and Sea of Marmara (Ostroumoff 1896).

Alvania scabra (Philippi, 1844)
(Fig. 5I, J)

Rissoa scabra Philippi, 1844

Mean dimensions (6 specimens): 1.70 (±0.11) × 1.01 (±0.05) – 1.12 (±0.05) mm [1.4 × 0.8 – 1.0 mm; 2.1 × 1.2 – 1.3 mm].

Remarks. Alvania scabra differs from similar Alvania species in having more spiral cords on the penultimate 4 and last whorls 7-8, respectively. The protoconch is paucispiral.

There are uncertainties about the synonyms of A. scabra. According to the Checklist of European Marine Mollusca (CLEMAM 2016), A. oranica was regarded as a synonym of A. scabra. van Aartsen (1982c) examined this idea and remarked that the mean difference between A. scabra and A. oranica consisted in having a fourth spiral (always) in the subsutural area of A. oranica, which is rarely found in A. scabra. In addition, Tringali (2001) indicated that the original description and figure of A. oranica given by Pallary (1900: 322, pl. 7, Fig. 4) was inadequate and still unclear and, due to this fact, A. oranica might be a synonym of A. sculptilis but not of A. scabra. Tringali (2001) also underlined that the figure of A. oranica provided by Gofas (1990: 130, Fig. 58) did not belong to A. oranica. He also stated that the figure of A. scabra in the study by van Aartsen et al. (1984) belongs to A. sculptilis (Monterosato, 1877) instead of A. scabra. In this study, we agree with Tringali’s opinion about the original description of A. oranica, which is insufficient and requires improvement.

Distribution. Mediterranean Sea (van Aartsen 1982c, Gofas et al. 2011). Turkish coasts: Levantine Sea (Buzzurro and Greppi 1996) and Aegean Sea (van Aartsen and Kinzelbach 1990).

Alvania testae (Aradas and Maggiore, 1844)
(Fig. 5K, L)

Rissoa testae Aradas and Maggiore, 1844

Mean dimensions (11 specimens and 2 shells): 2.26 (±0.05) × 1.22 (±0.03) – 1.42 (±0.03) mm [1.9 × 1.0 – 1.2 mm; 2.5 × 1.4 – 1.5 mm].

Remarks. Alvania testae is characterized by its shell shape. The shell is narrow and conical with 5-6 convex teleoconch whorls. Its protoconch is paucispiral. Aperture is roundish and outer lip opisthocline.

Distribution. Atlantic Ocean and Mediterranean Sea (Hoenselaar and Goud 1998, Gofas et al. 2011). Turkish coasts: Levantine Sea (Bitlis Bakır et al. 2012), Aegean Sea (Demir 2003, Öztürk et al. 2008) and Sea of Marmara (Ostroumoff 1896, Demir 2003).

Alvania marmarisensis n. sp.
(Figs 6A-F, 7A-E)

Type material and type locality: Holotype (ESFM-GAS/2014-10): Marmaris, 99 m, Aegean Sea; H: 3.3 mm, W: 1.9 mm, BWH: 2.2 mm. Paratypes: 11 specimens (ESFM-GAS/2014-10).

Mean dimensions (20 specimens): 2.96 (±0.08) × 1.84 (±0.03) – 2.07 (±0.04) mm [2.3 × 1.6 – 1.7; 3.5 × 2.1 – 2.4 mm].

Etymology. The name of the species is derived from the name of the area (Marmaris) where the specimens were found.

Description. Shell (holotype): Conical in shape, not very solid, with 4.5 less convex teleoconch whorls. Protoconch (holotype) is paucispiral (~1.25 whorls) and its nucleus diameter is about 0.150 mm. It has irregular spiral lines with rounded micro papillae in the interspaces.

Teleoconch (holotype) has four spirals on the penultimate whorl, 15 axial ribs in the last whorl, 4 spiral cords above the aperture, and 5 spirals on the base. The suture is deep, with a slope between the first and second spiral cords in the penultimate and last whorls. It has small granules at the intersections of the axial ribs, with spiral cords on the teleoconch whorls. There are also fine growth lines on the teleoconch. The aperture is large and ovate. The outer lip is thickened, with 7 internal denticles. It is light-brown coloured, while the apex is often darker. The soft parts and operculum were not examined.

Remarks. Among the species distributed along the Turkish Aegean coast, A. marmarisensis has some similarities with A. beanii, A. geryonia and A. mamillata (Fig. 7). However, it differs from A. beanii and A. geryonia in the number of protoconch whorls and rounded irregular micro papillae. The teleoconch whorls of A. beanii are more convex and have a greater number of axial ribs (24-26) and spiral cords (6-7). Alvania geryonia has a differently shaped teleoconch, with nearly flat whorls, and 5 spirals on the penultimate whorl. The protoconch of A. marmarisensis is also similar to that of A. mamillata (Verduin 1986: 28, Fig. 3; Oliver et al. 2015: 114, Figs 9, 10, 12, 13), but differs from A. mamillata in being more rounded and having large micro papillae on the protoconch whorls. On the other hand, A. mamillata has a more solid shell and a higher number of axial ribs on the last teleoconch whorl (14-20), and coarser granules at the intersections of the axial ribs with the spirals.

Alvania marmarisensis n. sp. is also morphologically similar to some other Mediterranean species, (i.e. Alvania dalmatica Buzzurro and Prkic, 2007, Alvania dianiensis Oliverio, 1988, Alvania hallgassi Amati and Oliverio, 1985 and Alvania oliverioi Buzzurro, 2003). The new species differs from Alvania dalmatica, A. dianiensis, A. hallgassi and A. oliverioi in the features of its protoconch and teleoconch, geographic distribution and depth ranges (Table 3). Alvania marmarisensis has 1.15-1.25 protoconch whorls, which are ornamented with 5-6 interrupted spiral threads with micro papillae in the interspaces, whereas A. dalmatica has 1.3-1.5 protoconch whorls bearing 6-7 spiral threads of the same thickness, with no papillae in the interspaces (Buzzurro and Prkic 2007: 6, Figs b, c). In addition, the new species has more spiral cords on the penultimate whorl (4 spirals against 3 in A. dalmatica) and on the last whorl (8-9 spirals against 5-9 spirals in A. dalmatica), but the number of denticles inside the outer lip of A. marmarisensis is smaller (6-7) than that of A. dalmatica (7-11). The colour of A. marmarisensis is light brown without coloured stripes as in A. dalmatica.

A. marmarisensis differs from A. hallgassi in having fewer axial ribs on the last whorl (13-17 against 15-40) and no coloured stripes on the whorls. Apart from the differences in the teleoconch, A. marmarisensis has a lower number of protoconch whorls (1.15-1.25 against 1.5 in A. hallgassi) bearing micro papillae in the interspaces between the spirals, which are smooth in A. hallgassi (Amati and Oliverio 1985: 34, Figs 1, 2).

Alvania marmarisensis also differs from A. oliverioi in having a higher teleoconch (h=2.3-3.5 mm against h=1.54 mm) and a small number of axial ribs on the last whorl (13-17 against 39-40). The protoconch of A. oliverioi consists of 1.4 whorls with 4-5 weak spirals and regular micro papillae on the whorls (Buzzurro 2003: 44-45, Figs 2-4) (Table 3).

The protoconch of A. marmarisensis is similar to that of A. dianiensis, except for the protoconch whorls (1.5) (Oliverio 1988: 120, Figs 2-7). Alvania marmarisensis is also larger (h=2.3-3.5 mm) and has a higher number of teleoconch whorls (4-4.5) than A. dianiensis (h=2-2.4 mm and 3.2 whorls). Alvania marmarisensis also bears a higher number of spiral cords on the last whorl (8-9 against 6-7), and 4 spirals against 3 spirals above the aperture. There are four spirals on the penultimate whorl in A. marmarisensis against 3 spirals in A. dianiensis. The other difference between the aforementioned two species regards the microsculpture of the teleoconchs; A. marmarisensis has only fine growth lines contrary to fine spiral striae in A. dianiensis (Oliverio 1988, Romani 2014).

There are also differences in the distribution areas and bathymetric ranges among A. marmarisensis and similar species (Table 3). With the exception of A. marmarisensis and A. dalmatica, all of the mentioned species were collected from infralittoral depths. Alvania marmarisensis was found at a depth of 99 m along the Aegean Sea coast (Marmaris) and Alvania dalmatica was recorded from the coasts of Croatia, Greece and the Adriatic Sea at depths ranging from 40 to 90 m (Buzzurro and Prkic 2007, Romani 2014). As regards the species that are similar to A. marmarisensis, A. dianiensis was reported from the Tyrrhenian, Ligurian and Adriatic Seas, from algal beds at depths ranging from 18 to 48 m (Oliverio 1988, Romani 2014), whereas Alvania hallgassi was described from infralittoral depths of the Ionian Sea (down to 20 m) (Amati and Oliverio 1985). This last species was also reported from Sicily, the Adriatic Sea, the Tyrrhenian Sea and the coasts of Cyprus (Oliverio et al. 1986, Cecalupo and Quadri 1996, Romani 2014). Alvania oliverioi was found along the Cypriot coastline at a depth of 4 m (Buzzurro 2003).