Tegillarca granosa ( Linnaeus, 1758 )

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) : -

9. Tegillarca granosa ( Linnaeus, 1758) ( Fig. 5 ; c & d)

1758. Arca granosa Linnaeus , 694

1844. Arca granosa Reeve , sp. 15

1844. Arca cuneata Reeve , sp. 37

1965. Arca granosa : Kundu, 40, pl.II, fig. 3a&b

1998. Arca granosa : Apte, 90

1988. Anadara (Tegillarca) granosa : Narasimham, 200-205 1998. Anadara granosa : Poutiers, 147

1998. Anadara (Tegillarca) granosa : Evseev & Lutaenko, 22 2010. Anadara granosa : Ramakrishna & Dey, 63

2017. Tegillarca granosa : Subba Rao, 62

Material examined: 1ex, Gopalpur (19°15.450’N and 084°54.557’E), 26-III-2007, coll. P. Yennawar ( MARC / ZSI M3566 ) ; 1ex, Gopalpur (19°15.259’N and 084°54.343’E), 27-III-2007, coll. P. Yennawar ( MARC / ZSI M3564 ) ; 1ex, Chandrabhaga (19°51.576’N and 084°06.409’E), 31-I-2008, coll. P. Yennawar ( MARC / ZSI M3565 ) ; 1ex, Jalda (Tajpur) (21°38.882’N and 087°38.094’E), 25-I-2008, coll. P. Yennawar ( MARC / ZSI M388 ) ; 6ex, Gopalpur (19°15.259’N and 084°54.343’E), 2-II-2008, coll. P. Yennawar ( MARC / ZSI M423 ) ; 1ex, Sagar Island (21°

37.508’N and 088° 04.405’E), 25-XII-2012, coll. P.C. Tudu ( MARC / ZSI M2840 ) ; 3ex, Chilka New Mouth (19° 39.486’N and 085° 31.050’E), 19-III-2013, coll. A. Mohapatra ( MARC / ZSI / M3644 ) ; 6ex, Kakinada (16° 54.492’N and 082° 14.370’E), 25-VI-2013, coll. A. Mohapatra & P.C. Tudu ( MARC / ZSI M3563 ) ; 1ex, Pulicat Lake (13˚25’ 27” N and 80˚19’ 26” E), 12-XII-2014, coll. P.C. Tudu ( MARC / ZSI / M4098 ) .

Description: Shell medium in size (L up to 50mm and H up to 41.3mm), equivalve, thick and solid. The shape of shell subtrigonal to globose, strongly inflated, to some extent length is more than high; antero-ventral margins widely arcuate, posterior margin slightly convex and rather elongated along the postero-ventral fold. Umbones strongly protruding, cardinal teeth area rather large. Radial ribs high, number of ribs 15-21; squarish in cross-section, roofed with unequal cross ridges of different height and widths, or with round or more or less squarish nodules; interspaces of ribs are U-shape and wider than ribs near the postero-ventral fold. Internal margin with strong crenulations; corresponding with the external radial ribs. Ligamental area trigonal in shape, with its maximum width under the beak, posterior part rather longer than the anterior part, chevron grooves unequal. Beak prosogyrate and tall.Hinge plate narrow and anterior series of teeth are shorter than the posterior series. No byssal gape. Periostracum greenish-pale to brownish in colour; thin and smooth. Outside of shell white in colour under periostracum, inner side white often tinged light yellow towards the umbonal cavity.

Distribution: In India; all maritime states including Andaman and Nicobar Island (Ramakrishna and Dey 2010), Elsewhere: Japan, Indonesia, East Africa, Vietnam ( Evseev and Lutaenko, 1998), China, Malaysia, Philippines, ( Evseev and Lutaenko, 1998; Poutiers, 1998), Singapore ( Tan & Woo, 2010), Indo-Pacific ( Subba Rao et al., 1992), Eastern Indian Ocean to tropical West Pacific ( Poutiers, 1998).

Remarks. According to Narasimham (1988), the number of radial ribs are 18-21, (21 st ribs is very faint); later Poutiers (1998) mentioned that ribs count is 15-20 and Evseev and Lutaenko (1998) stated that, number of radial ribs are 16-18, but in our specimens the range of ribs is 18-21, so, here we come to a conclusion, that the range of radial ribs is 15-21. This species is confused with another similar species T. nodifera ( Martens, 1860) , but having less number ribs, less number of nodules on ribs and less elongated shell compared to more ribs (19-23), more nodules and more elongated shell, in later one.

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.