Mosambicarca erythraeonensis (Jonas, 1851)

Tudu, Prasad Chandra, Yennawar, Prasanna & Mohapatra, Anil, 2019, First report of two ark shells, Anadara consociata (E. A. Smith, 1885) and A. troscheli (Dunker, 1882) (Arcidae: Anadarinae) from Indian waters with notes on morpho-taxonomy of some related species from east coast of India, Records of the Zoological Survey of India 119 (1) : -

8. Mosambicarca erythraeonensis (Jonas in Philippi, 1851)

( Fig. 5 ; a & b)

1997. Anadara erythraeonensis : Al-Khayat, 486

2010. Anadara erythraeonensis : Ramakrishna & Dey, 62

2006. Anadara (Mosambicarca) erythraeonensis : Lutaenko, pl.2, fig.D-E, pl.3, fig.A-D

Material examined: 2ex, Tuticorin (08°47.575’N and 078°09.636’E), 9-IX-2014 ( MARC / ZSI M4146 ) .

Description: Shell medium size (L up to 63mm and H up to 42mm), equivalve, solid, equilateral, obliquely ovate and elongate in outline at posteriorly, posterior margin less rounded; anterior margin convex, smoothly rounded ventrally, ventral margin narrower towards posterior. Umbones inflated, situated rather anteriorly, cardinal area narrow and elongate. Radial ribs 38-39 in number, ribs twice as wide as their interspaces, at least half of the anterior ribs are bisected with narrow and light groove, this groove is less deep than interspaces, arcuated in cross section and ornamented with irregular smaller ridges. Ligamental area less triangular, without ligamental grooves, its maximal wide situated posterior of the beaks. Beak prosogyrate and medium in height; slightly depressed in their middle part, hinge plate thickened, hinge series equal to each other, with the centre posterior of the beaks. No byssal gape. Periostracum brown in colour squamated, long cilia in the ventral side with coarse and velvety structure. Outside of shell white in colour covered with periostracum, inner side white and light yellow or whitish yellow in the umbonal cavity.

Distribution: In India: Tamil Nadu state (Ramakrishna and Dey, 2010); Elsewhere: Qatar ( Al-Khayat, 1997), throughout Indo-Pacific (Ramakrishna and Dey, 2010).

Remarks: This species shows resemblance with A. antiquata ( Linnaeus, 1758) but outline structure at posterior margin nearly straight, extending along the postero-ventral corner and radial ribs is solid as compared to less straight and rounded and radial ribs narrowly grooved in M. erythraeonensis (Jonas in Philippi, 1851).

Figures

Figure 5. a-b,Mosambicarca erythraneonensis (Jonas in Philippi, 1851), a-exterior of left valve, b- interior of left valve, c-d, Tegillarca granosa (Linnaeus, 1758); c- exterior of right valve, d- internal view of right valve; e-f, T. nodifera (Martens, 1860); e-exterior of left valve, f- interior of left valve; g-h, T. rhombea (Born, 1778); g-exterior of left valve, h-interior of left valve.