Lucinoma atalantae, Cosel, 2006

Cosel, Rudo von, 2006, Taxonomy of tropical West African bivalves. VI. Remarks on Lucinidae (Mollusca, Bivalvia), with description of six new genera and eight new species, Zoosystema 28 (4), pp. 805-851 : 830-832

publication ID	https://doi.org/ 10.5281/zenodo.4689802
DOI	https://doi.org/10.5281/zenodo.4892981
persistent identifier	https://treatment.plazi.org/id/666D2443-3E4B-FFB5-07D0-FA3FB544CA5E
treatment provided by	Felipe
scientific name	Lucinoma atalantae
status	sp. nov.

Treatment

Lucinoma atalantae n. sp.

( Figs 15C, D View FIG ; 16 View FIG )

TYPE MATERIAL. — Holotype:W of Mauritania, 20°32’N, 18°36’W, 2042 m, dredged RV Atalante, EUMELI 4, stn CP 16, 5.VI.1992, an alcohol preserved spm ( MNHN). GoogleMaps

Paratypes: same locality, 2 sh. ( MNHN).

TYPE LOCALITY. — Cape Verde Basin, W of Cap Blanc, Mauritania.

ETYMOLOGY. — Named after the RV Atalante, from which the type material was taken.

OTHER MATERIAL EXAMINED. — Mauritania. W of Cap Blanc, 20°41’N, 18°33’W, 2114 m, dredged RV Atalante, EUMELI 2, stn CP 03, 5.II.1992, 3 spm, 1 adult, 1 juv. sh. (MNHN). — 20°33’N, 18°35’W, 2003 m, dredged RV Atalante, EUMELI 2, stn CP 04, 5.II.1992, 1 juv. sh. (MNHN). — NW of Cap Blanc, 20°58.9’N, 18°13.6’W, 2112-2160 m, RV Discovery, stn 9133#5, 25.II.1976, 2 spm, 2 sh. (BMNH). — Same locality, 20°57.0’N, 18°11.0’W, 2110-2130 m, RV Discovery stn 11540, 2.IX.1987, 1 spm (BMNH).

DISTRIBUTION. — Only known from the Cape Verde Basin.

DESCRIPTION

Shell to 29mm long, rather solid, variable in outline and sculpture, subcircular (length/height ratio between 1.1 and 1.2), compressed.Anterior margin rather narrowly rounded, posterior margin more or less conspicuously truncated, occasionally slightly sinuous, with rounded corners.Ventral margin convex, nearly semi-circular. Beaks just in front of the vertical midline.

Exterior with numerous, very fine, irregular growth lines and commarginal lamellae which in juvenile specimens are very close-set and evenly spaced, in adult and subadult specimens they are more irregularly and wider spaced, obsolete or entirely missing. Earlier part of the valves often eroded. Posterior area delimited by gently rounded posterior angle, anterior angle absent. Lunule sunken, with rather thick layer of periostracum on it. Escutcheon long and very narrow, ligament slightly sunken.

Hinge plate moderately broad, with two well developed cardinal teeth in each valve; posterior cardinal in the left valve rather thin and laminar. Laterals more or less indistinct. Diverging part of anterior adductor scar long. Inner margin smooth.

Valves white. Periostracum very strong, yellowish brown, on the earliest parts of the valve thinner to obsolete.

Measurements are provided in Table 7.

BIOTOPE

In soft sediment, most probably mud, found between 2003 and 2160 m.

REMARKS

Lucinoma atalantae n. sp. is distinguished from L. vestita , the most similar species, by its larger size, the thinner and slightly longer valves, the narrower hinge plate and the sculpture. Lucinoma atalantae n. sp. shows dense commarginal lamellae on the earlier part of the valve whereas L. vestita is smooth. Juveniles of L. atalantae n. sp. are closer in outline to L. vestita but the narrower hinge line and the presence of commarginal lamellae remain distinguishing features. Both species have a different depth preference: L. vestita on the shelf slope at about 600 m, L. atalantae n. sp. much deeper, at about 2000 m. The two species have been taken at their type localities only, and we do not know their actual distribution range. Apart from an Indo-West Pacific species (under description by Cosel & Bouchet) which was found at 2570 m, L. atalantae n. sp. is the deepest-recorded lucinid species.