Cyclopecten capeverdensis Dijkstra & Goud, 2002
DIJKSTRA, H. H. & J. GOUD. 2002. Pectinoidea (Bivalvia, Propeamusidae & Pectinidae) collected during the Dutch CANCAP and MAURITANIA expeditions in the south-eastern region of the North Atlantic Ocean. CONCAP-Project contribution Nº 127. Basteria, 66: 31-81, figs. 1-77. [p. 42, figs. 27-32]
2002 Cyclopecten capeverdensis Dijkstra & Goud, 2002
H. H. Dijkstra & J. Goud, 2002, figures 27-32.
|
«Type material. — Holotype RMNH 92568, 13 paratypes RMNH 92569, HD.
Type locality. — CANCAP-VII: 7.038; Cape Verde Islands, SE of Chima; 14°57'N 24°38'W depth 410-460 m, yellow-grey calcareous sand and shell gravel with some basaltic pebbles; van Veen grab; 24.viii.1986. Material examined. — Canary Islands: 4.159. Cape Verde Islands: 6.006; 6.010; 6.017; 6.093; 6.149; 7.003; 7.004; 7.037;7.038; 7.039; 7.049; 7.100; 7.129; 7.177.
Distribution. — So far only known from the Canary Islands and the Cape Verde Islands, 28°40'N-14°53'N, 25°06'W-17°59'W, 100-610 m.
Description. — Shell up to c. 7 mm in height, fragile, opaque to semi-transparent, interior nacreous, semi-orbicular, somewhat higher than wide, inequivalve, equilateral. Left valve somewhat reticulated. Right valve commarginally sculptured. Auricles inequal. Prodissoconch c. 150 m. Left valve covered with delicate commarginal lamellae, more widely spaced near umbonal area. Irregularly arranged radial riblets, somewhat more prominent on the postero-marginal area, commence at 1.5 mm of the umbonal top and extend to the ventral margin. Anterior auricle more prominently sculptured with commarginal lamellae than posterior auricle. Right valve with closely spaced, regularly arranged commarginal lamellae, very weak in early ontogeny and more prominent in late ontogeny, and somewhat spiny on the postero-marginal area. Anterior auricle strongly developed with commarginal lamellae, which extend to antero-dorsal margin in a scaly sculpture, and some radial riblets, more prominent near the suture. Posterior auricle weakly sculptured with fine, closely spaced commarginal lirae. Hinge line straight. No internal riblets, except a small posterior auricular lira. Resilifer triangular. Cardinal crura strongly irregularly striated. Byssal notch small; no ctenolium. Measurements holotype: H 6.9 mm, W 6.7 mm, D 1.1 mm. Discussion. — Cyclopecten simplex Verrill, 1897, from the tropical western Atlantic and Cyclopecten ambiannulatus Schein, 1989 from the boreal and temperate eastern Atlantic are most closely related to C. capeverdensis. C. simplex has a weaker and more delicate sculpture on the left valve, sometimes rather smooth or only covered with minute irregularly spaced radial riblets. The cardinal crura is slightly broader. C. cancellatus is only sculptured with commarginal lamellae on the left valve and lacks auricular lirae. Etymology. — The present species is named after the Cape Verde Islands.» HENK H. DIJKSTRA & J. JEROEN GOUD, 2002
|