The determination and use of condition index of oysters

Oyster condition measures should be standardized through use of Hopkins’ formula: Condition Index = (dry meat weight in g) (100)/(internal cavity volume in cm³). Cavity volumes, previously measured chiefly as capacity by a water displacement method, may be determined by subtracting the weight in air of the oyster’s valves from the weight in air of the intact oyster (both in g). This method is valid because the effective density of cavity contents is close to 1g per cm³. The technique is simple and time-efficient and could promote more widespread use of oyster condition studies.