Systematic Classification

Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Pterioida
Family: Ostreidae
Genus: Crassostrea
Species: Crassostrea sp.
Chinese name: 蠔仔
Characteristic Features

Shape very irregular but commonly elongate. Surface roughened by irregular growth lamellae. Adductor muscle impression closer to ventral margin than to hinge. Lower valve usually cupped and upper valve generally quite flat and smaller. Color gray; interior white.

Habitat

On rocks, in intertidal, shallow waters; also found in mangrove swapms.
Size

Varies ~ 50 - 100 mm (shell length).
Distribution

Numerous in temperate and tropical seas.
Commercial
fishery		 Economically important. The common species Crassostrea gigas, commercial Pacific Oyster, is extensively cultivated in the Deep Bay area.