Sydney rock oyster Saccostrea commercialis
Distribution - Sydney rock oysters are endemic to Australia and inhabit sheltered estuaries and bays, from Hervey Bay in Queensland to Wingan Inlet in Victoria.
Size - Sydney rock oysters reach approximately 60g in 3 years, and have been known to live for up to 10 years.
Characteristics - They possess a smooth, thick shell with small teeth on the internal rim of the shell, generally near the hinge. The mantle edges and the adductor muscle scar are pale in colour.
Confusing species - The introduced Pacific Oyster (Crassostrea gigas) is now found throughout most of the range of the Sydney rock oyster. The Pacific oyster has a thin, rough shell with no hinge teeth on the upper shell, the mantle edges are black and the adductor muscle scar is purple/brown in colour.