Crassostrea Sacco, 1897

Lam, Katherine & Morton, Brian, 2004, The Oysters Of Hong Kong (Bivalvia: Ostreidae And Gryphaeidae), Raffles Bulletin of Zoology 52 (1), pp. 11-28 : 15-16

Crassostrea Sacco, 1897

Crassostrea Sacco, 1897: 15 ; Dall, 1898: 671; Hirase, 1930: 41; Stenzel, 1971: N1128-N1131; Torigoe, 1981: 304, 325; Harry, 1985: 152, 156; Coan et al., 2000: 216.

Dioeciostrea Orton, 1928: 320 .

Type species. – Crassostrea virginica, Gmelin, 1791 , by original designation.

Description. – Size varies among species and populations and can be up to 60 cm in height. Outline is variable among individuals but is usually high, slender and spatulate. Shell rough externally with many nonappressed, irregularly spaced growth squamae which are either simple or frilled along their free ends. Rounded radial ribs on some individuals, more common on left than on the right valve and tend to end as undulating ventral shell margins. Chambers are common. Well-developed umbonal cavity on left valve. No chomata. Adductor muscle scar close to postero-ventral valve margin. Ligamantal area on left valve well-developed with dense growth foliations. This always give rise to a well-developed, convex resilifer and ligamantal area on the right valve. Nonincubatory. Cosmopolitan.