Catillopecten, Iredale, 1939

Dijkstra, Henk H. & Maestrati, Philippe, 2008, New species and new records of deep-water Pectinoidea (Bivalvia: Propeamussiidae, Entoliidae and Pectinidae) from the South Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 77-114 : 99

Genus CATILLOPECTEN Iredale, 1939

Catillopecten Iredale, 1939: 347 , 370. Type species (by original designation): Pecten murrayi Smith, 1885 ; Challenger stn 184, east of Cape York, northern Australia, 12˚8’S, 145˚10’E, 2561 m.

Synonym:

Bathypecten Schein-Fatton, 1985: 491 . Type species (by original designation): Bathypecten vulcani Schein-Fatton, 1985 ; Central East Pacific, Cyana dive 33, 12˚48’80”N, 103˚56’60”W, 2620 m.

DIAGNOSIS. — Shell thin, translucent, flattened, inequivalve, left valve slightly more convex than right valve, left valve smooth or undulated, unsculptured or sculptured with weak commarginal lamellae, weaker on right valve, auricles nearly equal in size, unequal in shape, posterior auricles not delimited from disc. Byssal notch well-developed and rather deep, byssal fasciole very narrow or absent. No ctenolium.

DISTRIBUTION. — Atlantic, Indian, western and eastern Pacific Oceans; live in bathyal and abyssal depths (Waller 1984: 214).

REMARKS. — According to Schein (1989: 81) Bathypecten differs from Catillopecten mainly by having a weakly commarginally undulated left valve. However, examination of specimens in BMNH, MNHN, ZMA and ZMUC reveals that this undulation is highly variable and even absent from some specimens. This phenomenon is also recognized in Delectopecten and Hyalopecten in which the sculpture is highly variable or absent. Material of Bathypecten and Catillopecten varies from smooth to undulated without macro- or microsculpture or with weak commarginal sculpture on the left and right valve. Other characters (size, fragility, convexity, byssal notch, hinge line, coloration, cristallography) are very similar in these two genera.

Indo-Pacific species of Catillopecten are:

Catillopecten knudseni (Bernard, 1978) from the northeastern Pacific with a bathymetric range of 220-2900 m (most frequently 2700-2900 m).

Catillopecten squamiformis (Bernard, 1978) from the northeastern Pacific (2030-2884 m).

Catillopecten graui (Knudsen, 1970) from the eastern Pacific (3270-3670 m).

Catillopecten vulcani ( Schein-Fatton, 1985) from the Eastern Pacific Rise (2620 m).

Catillopecten translucens (Dautzenberg & Bavay, 1912) from Indonesia (1301 m).