Publication Abstract

Acute toxicity of invermetin to the lugworm

J.E. Thain, I.M. Davies, G.H. Rae and Y.T. Allen

Ivermectin (22,23-dihydroavermectin B1a and B1b), as the commercial Premix for Pigs, was found to be acutely toxic to the marine sediment-dwelling polychaeteArenicola manna (10-day LC50 0.023 mg/kg dry weight of sediment, confidence limits 0.018 and 0.027 mg/kg). At all concentrations tested (i.e. 0.006 mg/kg and above), ivermectin reduced the rate of cast production. Prior exposure to 0.010 mg/kg or more reduced the rate at which A.marina was able to rebury in clean sediment. The results indicate that there is a clear case for the targeted field studies at marine salmon farming sites where permission may be given to use ivermectin to control ectoparasitic sea lice infections.

Reference:

J.E. Thain, I.M. Davies, G.H. Rae and Y.T. Allen, 1997. Acute toxicity of invermetin to the lugworm. Aquaculture 159: 47-52