Acute Toxicity of Agricultural Pesticides to Embryo-Larval and Juvenile African Catfish Clarias gariepinus

Acute toxicities of Tihan 175 O-TEQ, as well as its active ingredients flubendiamide and spirotetramat, and of Thionex 350 EC (active compound endosulfan) were measured for embryo-larval and juvenile stages of the African catfish Clarias gariepinus to assess risks of pesticide use in the cotton basin in Benin (West Africa). For embryo-larval stages, Tihan was more toxic (LC50 48h 20 ppm) than Thionex (LC50 48h 56 ppm), and flubendiamide was more toxic (LC50 48h 2.0 ppm) than spirotetramat (LC50 48h 8.44 ppm). All decreased hatching rates. Tihan and spirotetramat disturbed larval swimming coordination; flubendiamide induced tail cleavage. For juvenile fish, Thionex was more toxic (LC50 96h 0.22 ppm) than Tihan (LC50 96h 8.8 ppm), and flubendiamide (LC50 96h 4.7 ppm) was more toxic than spirotetramat (LC50 96h 6.0 ppm). Eggs were more resistant than juvenile fish to all tested pesticides except flubendiamide. Although Thionex was more toxic to juvenile fish, replacing Thionex with Tihan may be undesirable for survival of eggs and larvae.