PROPEAMUSSIIDAE  

Cyclopecten acutus

Grau, 1959

Figure(s)

 

rv                     Holotype                     lv

Original name   Cyclopecten acutus Grau, 1959
Autoreference   Grau, 1959: 31, pl. 10, fig. 2.
Reference   Grau, G., 1959. Pectinidae of the eastern Pacific. Allan Hancock Pacific Expeditions, vol. 23: i-viii, 1-308, 57 pls. University of Southern California Press, Los Angeles.
Type data

  Holotype (pr: H 3.75 mm, L 3.75 mm, D 1.50 mm) Hancock Foundation (now in Natural History Museum of Los Angeles County, Los Angeles) (LACM 1746).Type locality: LACM 38-233 [ex AHF BS-584], W Colombia, Cauca Dept., off N-side of Isla Gorgona, 03*1'N, 78*11'W, 59 m, alive, 24.ii.1938 (RV "Velero" III).

Description

  Shell up to ca. 4 mm high, fragile, opaque, weakly inflated, left valve slightly more convex than right valve, subcircular, slightly inequivalve, equilateral, auricles equal in size, unequal in shape, internal ribs lacking, umbonal angle ca. 90 degrees, colour left valve white or yellow-white with streaks or blotches of yellow or yellow-brown, right valve white or yellow-white, margin colourless and transparent.

  Left valve and right valve a few prominent rows of commarginal lamellae in early growth stage, disc nearly smooth with extremely faint commarginal ridges. Auricles of left valve with numerous faint radial ridges. Anterior auricle of right valve with delicate commarginal lamellae.

Byssal notch shallow, byssal fasciole and ctenolium lacking.

Distribution

 

 

West Colombia (TL), Ecuador

Habitat  Living lower littorally and upper bathyally on soft bottom assemblages.