Journal of the Marine Biological Association of India

Salinity tolerance, survival, behaviour and weight changes of the wedge clam Donax cuneatus.

Volume 18 Issue 3

P. M. Talikhedkar and U. H. Mane

Abstract

The wedge clam, Donax cuneatus tolerates salinity dilution upto 22.05 %„. In the medium having less than 18.9 %„ salinity value, the wedge clams show erratic behaviour and 100% mortality occurred at 9.45 %„ salinity at the end of 10 days of experiment. The time of opening of the valves of the wedge clam progressively increased with increase in salinity irrespective of the nature of transfer (sudden or gradual).

On shelling the body of the wedge clam, more weight was lost in the injured than in the non-injured clam, but the mechanism of fluid loss in both the cases was the same. The wedge clams prevented from opening and closing their valves lost weight both in air and water due to the secretion of body fluids. The weight loss in wedged open clams was found to be directly proportional to the dilution of the seawater (31.5%„), whereas the weight changes in intact clams showed no definite correlation with the dilution of the seawater

Date : 31-12-1976