We examined physiological responses related to the survival, oxygen consumption and filtration rate of the blood cockle, Tegillaarca granosa as a result of salinity changes. The 44-day LS50 (median lethal salinity) at 10¨¬C for adult and juvenile was 15.8 (confidence limits 13.5-18.2 psu) and 16.2 (confidence limits 14.1-18.4 psu) psu respectively, whereas the 11-day LS50 at 25¨¬C for adult and juvenile was 16.8 psu (confidence limits 12.9-21.2 psu) and 22.4 (confidence limits 20.5-24.7 psu) psu respictively. In conditions of decreasing salinity, Oxygen consumption and filtration rates decreased or varied irregularly as salinity decreased. The results of this study could prove important in investigating causes of mass mortality and managing shellfish aquaculture farms.