Solelucina koumacia, Glover & Taylor, 2007

Glover, Emily A. & Taylor, John D., 2007, Diversity of chemosymbiotic bivalves on coral reefs: Lucinidae (Mollusca, Bivalvia) of New Caledonia and Lifou, Zoosystema 29 (1), pp. 109-181 : 126-127

publication ID	https://doi.org/ 10.5281/zenodo.5392295
DOI	https://doi.org/10.5281/zenodo.5468546
persistent identifier	https://treatment.plazi.org/id/039087F4-FFD0-6A30-13F6-FD86FB9CD6C6
treatment provided by	Marcus
scientific name	Solelucina koumacia
status	sp. nov.

Treatment

Solelucina koumacia View in CoL n. sp.

( Figs 6E View FIG ; 10 View FIG ; 11 View FIG )

TYPE MATERIAL. — Holotype: 1 sh, L 14 mm, H 9.9 mm, T 3.2 mm ( MNHN).

Paratypes: New Caledonia, Baie de St Vincent , stn 163, 22°12’S, 166°08’E, 15 m, 3 sh, L 17.1 mm, H 11.2 mm GoogleMaps ; L 21.0 mm, H 15.2 mm; L 14.4 mm, H 9.6 mm ( MNHN). — New Caledonia, Touho, Grand Récif Mengalia, 20°45.2’S, 165°16.3’E, intertidal, stn 1245, 1 sh, L 17.4 mm, H 12.0 mm ( MNHN). — Loyalty Islands, Lifou , Baie du Santal , stn 1463, 20°55.05’S, 167°03.35’E, 20-30 m, 5 sh, L 15.4 mm, H 10.6 mm GoogleMaps ; L 13.5 mm, H 9.0 mm; L 11.8 mm, H 8.5 mm; L 12.3 mm, H 9.3 mm; L 9.3 mm, H 6.8 mm ( BMNH 20050571 ) .

TYPE LOCALITY. — New Caledonia, stn 98, Île Ouen, Baie du Prony, 22°36’S, 166°32’E, 15 m.

ETYMOLOGY. — Koumacia , derived from the locality Koumac, New Caledonia.

MATERIAL EXAMINED. — Koumac. 8 stn, 0-120 m, 35 v, 4 live.

Touho. 1 stn, 0 m, 1 live.

Lifou. 10 stn, 4-45 m, 147 v, 15 live.

Chesterfield Islands. CORAIL 2, stn DW 04, 20°52’S, 161°37’E, 64 m, 1 v. — Stn DW 28, 20°28’S, 160°56’E, 78 m, 1 v. — Stn DW 32, 19°25’S, 158°49’E, 55 m, 1 sh. — Stn DW 60, 19°15’S, 158°57’E, 45 m, 3 v. — Stn DW 85, 19°12’S, 158°57’E, 32 m, 1 v. — Stn DW 87, 19°06’S, 158°60’E, 31 m, 1 sh. — Stn DW 91, 19°03’S, 158°55’E, 43 m, 2 v. — Stn DW 146, 19°47’S, 158°16’E, 44 m, 1 sh, 1 v. — Stn DW 147, 19°37’S, 158°14’E, 25 m, 2 v. — Stn DW 160, 19°46’S, 158°23’E, 35-41 m, 1 sh, 1 v.

Other New Caledonia. LAGON, stn 293, Grand Récif du Sud, 22°42’S, 166°41’E, 20 m, 4 v. — Stn 341, 22°49’S, 166°46’E, 19 m, 1 v. — Stn 544, 22°51’S, 166°49’E, 25 m, 1 sh, 1 v. — Stn 98, Île Ouen, Baie du Prony, 22°36’S, 166°32’E, 15 m, 2 v. — Stn 163, Baie de St Vincent, 22°12’S, 166°08’E, 15 m, 3 sh. — Stn 218, 15 m, 21°52’S, 165°46’E, 1 sh. — Stn 49, secteur de Nouméa, 22°19’S, 166°14’E, 10 m, 1 sh. — Stn 1015, secteur de Poum, 20°10’S, 163°52’E, 25 m, 1 sh.

HABITAT. — Intertidal to 50 m, sandy reef platforms and seagrass.

DISTRIBUTION. — Western Pacific: Chesterfield Bank, New Caledonia, Loyalty Islands.

DESCRIPTION

Shell medium size H to 18.8 mm, L to 23.3 mm, elongate oval in outline, longer than high H/L 0.7, posterior margin blunt, anterior margin rounded, moderately inflated T/L 0.2. Posterior dorsal margin straight, long, sloping, with slightly extended dorsal margin. Anterior dorsal margin shorter, rounded. Posterior dorsal area demarcated by one or two low ridges. Umbones low, located anterior of centre. Periostracum, thin, fibrous, buff coloured. Juvenile shell to around 2.5 mm shell height with 11 or 12 thin, low, widely, but regularly spaced, commarginal lamellae ( Fig. 11A View FIG ). Protoconch flat (170 µm), PI large, PII a narrow rim. Adult shell smooth, glossy, with fine growth increments. Shell colour creamy white, often with up to 10 prominent, pink-orange, radial rays, that are solid or interrupted ( Fig. 10 View FIG ). Lunule elongate, lanceolate, usually symmetrical. Escutcheon prominent, long, deep. Lunule and escutcheon areas glossy and often coloured dull orange. Ligament external, short. Hinge plate thin, RV with single cardinal, and a socket, anterior lateral low elongate, posterior lateral a low ridge. LV with single cardinal, lateral teeth absent. Anterior adductor muscle scar short, reniform, detached from pallial line for 1/4 of length. Anterior pedal retractor scar distinct. Posterior adductor scar short, reniform. Pallial line entire, broad. Shell outside pallial line glossy white to pale orange. Shell margin smooth. Shell interior glossy, sometimes slightly ridged and thickened, white to pale yellow.

Anatomy

Observations on a rehydrated body show this bivalve has typical lucinid features – ctenidia with thick single demibranchs only, highly reduced labial palps, a large foot and two posterior apertures. The exhalant aperture has a short eversible tube and there is a short length of mantle fusion ventral to inhalant aperture.

REMARKS Myrtea pseudocorbis Nicklés, 1952 , from West Africa, has a similar elongate shell, hinge teeth and adductor muscle but differs in the prominent concentric lamellae over all the shell.