Tributyl tin oxide (TBTO) has been recognised as a serious health haza
rd. Edible green mussel Perna viridis was highly sensitive to TBTO (LC
50/28 d = 0.28 mug.l-1). The oyster species Saccostrea cucullata on th
e other hand possessed good tolerance to TBTO (LC50/28 d = 10 mug.l-1)
. Fouling mussel Mytilopsis sallei has been found to show very high to
lerance to TBTO (LC50/28 d = 13 mug.l-1). It was also observed that th
e amount of TBTO determined as inorganic tin, bioaccumulated by P. vir
idis and S. cucullata were inversely proportional to the concentration
s of TBTO to which they were exposed.