Effects of chromium(VI) and vanadium(V) on the lifespan of fish

The effect of chromium(VI) on the lifespan of laboratory-reared guppies (Poecilia reticulata) has been studied both in the absence and in the presence of the antioxidant d-mannitol, and it has been compared with that produced by vanadium(V). The three substances used as additives exhibited either a weak (d-mannitol), a moderate (chromate) or an acute (vanadate) toxicity to fish. Vanadate, with LC50 (7 days)=3.84×10−5 mol/L, was about ten times more toxic than chromate, with LC50 (7 days)=3.42×10−4 mol/L as a single additive and 4.27×10−4 mol/L in the presence of d-mannitol. An increasing effect on the maximum lifespan of males was observed when the additives studied were used at low concentrations, either alone or in a binary combination, following the sequence: vanadate (14%)