Differential Sensitivity to Vegetable Tannins in Planktonic Crustacea from Alpine Mosquito Breeding Sites

The differential capability to detoxify dietary tannins from the leaf litter of the vegetation surrounding alpine mosquito communities was experimentally investigated in different strains of planktonic crustacean taxa (Daphnia pulex, Simocephalus vetulus, and Eucypris virens) associated with the culicine populations. Tannic acid, used as an experimental standard, had differential biocidal effects in strains associated with various surrounding vegetation with different phenolic contents. Such a differential sensitivity to tannic acid was correlated with qualitative and quantitative features of cytochromes P-450, esterases, and glutathione Stransferases activities measured in these strains. This suggests that these enzymes are involved in the detoxification of vegetable tannins by these crustacean taxa. Contribution of cytochromes P-450, esterases, and glutathione S-transferases in the resistance of Crustacea to those xenobiotics was also implied by the synergistic effect in vivo of piperonyl butoxide and S,S,S, tributyl phosphorotrithioate on the toxicity of tannins.