Effects of the herbicide alachlor on larval development of the mud crab,Rhithropanopeus harrisii (Gould)

The effects of the herbicide alachlor, in both technical grade and commercial product form (Lasso), were tested for acute toxicity on larvae of the estuarine crabRhithropanopeus harrisii. The generalized effect is a reduction in survival and a lengthening of developmental time with an increase in concentration. The LC₅₀ values were inversely proportional to exposure time and ranged from 10 to 27 mg l^?1. Lasso was slightly more toxic than technical grade alachlor.