Cryptomya (Cryptomya) busoensis Yokoyama, 1922

Zhang, Jun-Long, Xu, Feng-Shan & Liu, Rui-Yu, 2012, The Myidae (Mollusca, Bivalvia) from Chinese waters with description of a new species, Zootaxa 3383, pp. 39-60 : 46

Cryptomya (Cryptomya) busoensis Yokoyama, 1922

Figure 4A

Cryptomya busoensis Yokoyama, 1922: 126 , pl. 7, figs. 1 & 2— Beets, 1950: 16; Habe, 1951: 75, pl. 12, figs. 1 & 2; Habe, 1961: 140, pl. 63, fig. 13; Habe, 1968: 205, pl. 63, fig. 13; Kuroda et al. 1971: 704, 463; pl. 121, fig. 7; Habe, 1977: 279, pl. 58, figs. 5 & 6; Xu, 1987: 438, fig. 1c; Darkina & Lutaenko, 1996: 79; Xu, 1997: 229; Lutaenko, 1999: 272 –273; Okutani, 2000: 1021, pl. 508, fig. 7; Kwon et al. 2001: 277, fig. 1133; Lutaenko, 2003: 26; Lutaenko et al. 2003: 168, pl. 5, fig. 10; Xu & Zhang, 2008: 257, fig. 811; Xu, 2008: 589; Lutaenko, 2005: 76.

Cryptomya (Cryptomya) busoensis M. Yokoyama, 1922 — Huber, 2010: 461 (text-fig.).

Material examined. MBM078482 (specimen broken into small fragments and not figured, therefore), South Yellow Sea, Station 3056 (35°N, 119°45’E), 45m, in mud, collected by Lv, on October 27th, 1958.

Distribution and habitat. Miocene to Recent. Yellow Sea, Lianyungang, China; Japan; Korea; Russia. Mud bottom in intertidal zone to 60m depth. Occurs in macrosymbiotic association with thalassinoidean shrimps ( Itani & Kato 2002; Nara & Kotake 1997; Nara et al. 2008).

Type locality. Otake, Chiba Prefecture, Honshu, Japan, Pleistocene.

Diagnosis. Length to 15 mm; shell laterally compressed, elongate; umbo low, situated subcentral; posterior area bound anteriorly by radial ridge; sculpture of thin commarginal lines; hinge of left valve with a large triangular chondrophore; pallial sinus not reaching further anterior than posterior adductor scar or lacking; pallial line continuous, obscure.

Remarks. This species was previously regarded as a synonym of C. californica ( Bernard 1983; Coan et al. 2000), but is now recognized as a distinct species distinguished by its smaller and more elongate shell ( Coan & Valentich-Scott 2012; Huber 2010).

Figures

FIGURE 4. A. Cryptomya (Cryptomya) busoensis Yokoyama, 1922 (from Xu, 1987: fig. 1 c). Scale bar = 5 mm. B – O. Cryptomya (Venatomya) elliptica (A. Adams, 1851). B – E. MBM 264725, length = 11.4 mm. B. Exterior of right valve. C. Exterior of left valve. D. Interior of right valve. E. Interior of left valve. Scale bar (B – E) = 5 mm. F – I. MBM 264726, length = 14.9 mm. F. Exterior of right valve. G. Exterior of left valve. H. Interior of right valve. I. Interior of left valve. Scale bar (F – I) = 5 mm. J – O. MBM 264727, length = 23.3 mm. J. Exterior of right valve. K. Exterior of left valve. L. Interior of right valve. M. Interior of left valve. Scale bar (J – M) = 5 mm. H. Hinge of left valve. Scale bar = 5 mm. O. Close up of surface sculpture. Scale bar = 5 mm.