Comparative sensitivity of embryo-larval toxicity assays with African catfish (Clarias gariepinus) and zebra fish (Danio rerio)

Embryo-larval toxicity tests with the African catfish (Clarias gariepinus) were conducted with five chemicals (Cr, Cd, Zn, NaPCP and malathion) and th ree environmental samples. The sensitivity of the 5-day assay was compared to that of the 12-day embryo-larval toxicity tests with the zebra fish (Dan io rerio). The ratios of the C. gariepinus and D. rerio LC50 values ranged from 0.4 for Cr to 8.9 for Zn. The ratios of subchronic values ranged from 0.25 for NaPCP to 3.1 for Cd indicating a more comparable sensitivity of th e two species. For the three sediment pore waters, the ratios were 0.6, 1.1 , and 2.4 and the subchronic values were identical for the two species. The results suggest that, considering the short-test duration and its sensitiv ity, the 5-day embryo-larval tests with C. gariepinus may be a potential al ternative for short-term embryo-larval toxicity testing with fish. (C) 2001 by John Wiley & Sons. Inc.