The genus Cerithidea Swainson, 1840 (Gastropoda: Potamididae) in the Indo-West Pacific region Author Reid, David G. text Zootaxa 2014 3775 1 1 65 journal article 36884 10.11646/zootaxa.3775.1.1 c2c6d40e-39c0-477c-9bc2-8eae0c3dd816 1175-5326 285731 D9FF6080-0316-4433-ABB8-7D6D6F2BF24B Cerithidea sinensis ( Philippi, 1848 ) ( Figures 6 , 7A–L ) Cerithium (Potamides) sinense Philippi, 1848 : 19 –20 ( China ; 2 syntypes MNHN 25694, Fig. 7A, B ). Cerithium sinense — Philippi, 1849 : 18 , Cerithium pl. 1, fig. 15. Sowerby, 1855 : 886 , pl. 186, fig. 274. Cerithidea sinensis —H. Adams & A. Adams, 1854: 293. Adams, 1855 : 83 . Sowerby, 1866 : sp. 17, pl. 3, fig. 17. Mabille, 1887 : 158 . Yen, 1936 : 206 –207, pl. 17, fig. 29. Fan, 1989 : 37 –38, pl. 5, fig. 15. Ma, 2004 : 38 , pl. 016D, fig. 13 (map). Kojima et al ., 2006 : 525 –535, fig. 2h. Zhang, 2008 : 60 , fig. Li & Huang, 2012 : 152 , fig. Reid et al ., 2013 : figs 1 (phylogeny), 2 (map). Potamides (Cerithidea) sinensis — Tryon, 1887 : 164 –165, pl. 34, figs 97, 98. Cerithium (Cerithidea) sinense — Kobelt, 1890a : 68 –69, pl. 13, figs 8, 9. Cerithidea (Aphanistylus) sinensis —Casto de Elera, 1896 : 330 . Dautzenberg & Fischer, 1905 : 136 –137. Potamides (Aphanistylus) sinensis — Fischer, 1891 : 164 . Fischer & Dautzenberg, 1904 : 416 . Aphanistylus moreleti Wattebled, 1886 : 59 –60, pl. 4, fig. 5 (Thuan-an, dans la rivière de Hué, Annam [Thuan An, Hue, Vietnam ]; 4 syntypes MNHN 25687; 1 syntype MNHN 25688, Fig. 7J ). Potamides (Aphanistylus) moreleti — Fischer, 1891 : 164 . Fischer & Dautzenberg, 1904 : 416 . Cerithidea (Aphanistylus) moreleti — Dautzenberg & Fischer, 1905 : 138 –139. Cerithidea (Cerithidea) rhizophorarum — Cecalupo, 2006 : 147 , 239 (not A. Adams, 1855 ). Taxonomic history. There are two syntypes of Cerithium sinense in MNHN, respectively 18.6 mm ( Fig. 7B ) and 27.8 mm ( Fig. 7A ) in height; the latter is larger than either the dimension given in the original description (8 lines [ 17.4 mm ]; Philippi 1848 ) or the figure subsequently published by Philippi (1849: 18 mm ) . Nevertheless, the two are conspecific and were collected by Largilliert in China (as in the original description), so both are regarded as syntypes . Cerithidea rollei Kobelt, 1890b was based on shells said to come from China and figures by Kobelt (1890a) bear a superficial resemblance to C. sinensis . However, this is a synonym of Cerithideopsis scalariformis from the western Atlantic (see Excluded and doubtful species). Tryon (1887) first suggested the synonymy of C. moreleti with C. sinensis . Fischer (1891) listed both, but Dautzenberg & Fischer (1905) remarked on their close similarity, while provisionally retaining them as separate species. The records of C. charbonnieri from northern Vietnam in early French literature probably apply to C. sinensis (e.g. Mabille, 1887 ; Crosse & Fischer, 1890 ; see Range of C. charbonnieri ). Diagnosis. Shell: delicate, small, narrow, straight-sided, periphery rounded; sinuous apertural margin, weak anterior canal; 14–19 rounded axial ribs on penultimate whorl, ventrolateral varix often absent; no spiral sculpture above periphery; weakly lined pattern. China , northern Vietnam . COI GenBank HE680295 – HE680297 . Material examined. 25 lots. Shell ( Fig. 7A–L ): H = 16.7–28.6 mm . Shape narrowly elongate (H/B = 2.25–2.78, SH = 3.01–3.45); decollate, 6–7 whorls remaining; spire whorls rounded, suture distinct; spire profile almost straight; periphery rounded; delicate. Adult lip only moderately thickened and flared; rarely, 1–3 previous lips on final whorl ( Fig. 7I ); apertural margin sinuous in side view; weak anterior projection adjacent to shallow notch of canal. Sculpture on spire of straight to slightly opisthocline axial ribs, becoming slightly curved (opisthocyrt) and weak on final whorl, ribs rounded, ribs and interspaces of equal width, 14–19 ribs on penultimate whorl; spiral sculpture absent above periphery; base with 8–10 striae, of which 2 at periphery are slightly more prominent. Ventrolateral varix usually absent or indistinct; if present, at 90–140° (1 spec. with 2 varices, at 160 and 200°). Surface with very faint spiral microstriae on periostracum; shiny where periostracum worn away. Colour: fawn to pale brown; 0–2 narrow brown bands above periphery; almost always a strong brown band just below periphery, sometimes another adjacent to columella; periostracum olive brown; bands visible within aperture. FIGURE 7. A–L, Cerithidea sinensis . M–V, C. charbonnieri . A, B, Cerithium sinense Philippi, 1848 , syntypes, China (MNHN 25694). C, D, Shanghai, China (NHMUK 20130235). E–I, L, Hai Phong, Vietnam (USNM 207877; E–H views of same specimen). J, Da Nang, Vietnam (NHMUK 1901.12.12.175). K, Aphanistylus moreleti Wattebled, 1886 , syntype, Huan An, Hue, Vietnam (MNHN 25687). M–R, Tapi River estuary, Surat Thani, Thailand (NHMUK 20100424; N, R and O–Q views of two specimens). S, Lubok Antu, Sarawak, Malaysia (NHMUK 20130236). T, U, Cerithium unicarinatum Metcalfe, 1852 , syntype, Borneo (NHMUK 20130226). V, Cerithium charbonnieri Petit de la Saussaye, 1851, syntype, Borneo (MNHN 25689). Photography credits: A, B, K, V, MNHN. Animal: Head and foot cream with grey mottling; snout with two transverse black bands, tip yellow; tentacles yellow at base with black stripe across eye; edge of foot mottled yellow; mantle edge pale grey (based on ethanolpreserved specimens). Range ( Fig. 6 ): Asian mainland from Yellow Sea to N Vietnam . Records: China : Liaoning to Jiangsu ( Ma, 2004 ); Shanghai ( NHMUK 1867.5.18.14); Ningbo ( ANSP 18093); Un-Long, Kowloon, Hong Kong ( USNM 516424). Vietnam : Haiphong ( NHMUK 1893.12.8.120; USNM 207877; MNHN ) ; Nam Dinh, Tonkin ( MNHN ); Da Nang ( NHMUK 1901.12.12.175; MNHN ; ZMB ). Ma (2004) reported this species to be restricted to northern China , but records are here extended south to Vietnam . Pilsbry (1895) recorded it from the Yaeyama Islands at the southern end of the Ryukyu chain, but all other records are from continental coasts, so this is considered unlikely and could refer to small specimens of C. moerchii . Habitat and ecology. Yen (1936) reported it to be very common in brackish water at a river mouth (Shantung Peninsula). The type locality of Aphanistylus moreleti is the Hue River, where Wattebled (1886: 59) noted that it was “fairly common”. Records from southern China and Vietnam are scarce, suggesting that it may be less frequent there. It has not been recorded if this species climbs on vegetation, but its range in the north of China lies beyond that of mangrove trees. Remarks. This species is well known in the Chinese literature, but not elsewhere, and is scarce in western museum collections. Specimens from the extreme south of the range at Da Nang and Hue in northern Vietnam are smaller ( Fig. 7J, K ) than the typical form from China ( Fig. 7A–D ), but the two appear to integrade at Haiphong in northern Vietnam ( Fig. 7E–L ). The southern form was recognized as C. moreleti by some early twentieth century authors (see Synonymy). Apart from size, there are no consistent differences in the shells of northern and southern forms, but their conspecificity needs to be tested with molecular data. There is geographical overlap with C. tonkiniana over much of the range. Dautzenberg & Fischer (1905) considered tonkiniana to be a variety of C. sinensis and the two names have been confused on some museum samples. The shell of C. tonkiniana is larger (to 38.1 mm ), more solid, has a strong ventrolateral varix and 5 weak spiral ridges above the periphery (if not eroded; Fig. 13 N–Y); the ventrolateral varix and spiral ridges are absent in C. sinensis . It is unclear if the two differ ecologically, but C. sinensis possibly occurs in habitats of lower salinity. Comparison with the two most closely related congeners, C. balteata and C. charbonnieri , is discussed in the Remarks on C. balteata . Another potamidid that is broadly sympatric with C. sinensis is Cerithideopsis largillierti . The latter species is not decollate, has more rounded whorls, the axial ribs are more numerous (20–26 on penultimate whorl), the basal cords are more pronounced, the aperture is more strongly sinuous in side view and is not flared, the periostracum is thicker with strong, slightly bristly striae and the living animal is black with yellow tip to the snout and yellow tentacle bases.