Acute toxicity of organotin compounds to the larvae of the rock shell, Thais clavigera, the disk abalone, Haliotis discus discus and the giant abalone, Haliotis madaka

Acute toxicity tests of tributyltin (TBT) and triphenyltin (TPT) were conducted on hte larvae of the rock shell, Thais clavigera, the disk abalone, Haliotis discus discus and the giant abalone, Haliotis madaka. For the rock shell larvae, the LC50 values (based on the nominal concentrations) were 8.4 μg (24 h) and 5.6 μg (48 h) TBT/IL; 8.6 μg (24 h) and 4.6 μg (48 h) TPT/L. For the disk abalone larvae, the 48 h LC50 values were 5.4 μg TBT/L and 1.4 μg TPT/L. For the giant abalone larvae, the LC50 values were 3.9 μg (24 h) and 1.2 μg (48 h) TBT/L; 2.4 μg (24 h) and 1.5 μg (48 h) TPT/L. Some effects on swimming behavior (e.g. unusual swimming behavior or low swimming activity) and irregular movement of cilia due to atrophy of velum compared to that in the control, as well as stripping out of the larvae from the shell, were observed even at lower concentrations than the LC50 values. From these experimental results and actual organotin concentrations in Japanese inshore waters, TBT pollution may have adversely affected the recruitment of the rock shell, the disk abalone and the giant abalone in heavily polluted areas.