THE ACUTE LETHAL TOXICITY OF HEAVY-METALS TO PERACARID CRUSTACEANS (WITH PARTICULAR REFERENCE TO FRESH-WATER ASELLIDS AND GAMMARIDS)

In static tests on the acute toxicity of metal salts to two fresh-water peracarids, Asellus aquaticus (L. ) (Isopoda) and Crangonyx pseudogracilis Bousfield (Amphipoda), 48 and 96 h LC//50 values were determined for Al(III), Cd(II), Cr(III), Cu(II), Fe(III), Hg(II), Mn(II), Ni (II), Pb(II) and Zn(II). Additional metals tested upon Crangonyx alone were Ag(I), Co(II), Cr(VI), Fe(II), Mn(VII), Mo(VI), Sn(II) and V(V). Of the metal salts tested on both species, Asellus was more sensitive to Al(III) and Mn(II) than Crangonyx, similarly sensitive to Cd(II), Fe(III) and Zn(II), and less sensitive to the remainder. Toxicity of metal salts which are unstable with respect to reduction or oxidation was found to be higher than that of the corresponding stable salts of the same metal. Previously published data on the acute toxicity of heavy metal salts to fresh-water, estuarine and marine amphipods and isopods are tabulated and discussed.