Salinity tolerana, lethal lower salinity and mortality rates in different salinity treatments of the small (15-20 mm APM) and large (30-35 mm APM) venerid clam, Paphia malabari~a were studied. The studies revealed that on sudden exposure from a pre-acclimation salinity of 22 ppt, both the size groups could tolerate a salinity range of 12 ppt to 40 ppt. The lethal lower salinity was determined based on 5Wo mortality. It was seen that larger clams are more tolerant to lower salinities. Between 20 ppt and 30 ppt both the size groups recorded no mortality. Observations on the conditioning time showed the fastest conditioning between 20 'ppt and 30 ppt Large clams conditioned faster in lower salinities and vice versa in higher salinities.

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