Sensitivity to uranium of six species of tropical freshwater fishes and four species of cladocerans from Northern Australia

Abstract

AbstractThe toxicity of uranium to the tropical freshwater fishes —black‐banded rainbowfish (Melanotaenia nigrans), chequered rainbowfish (Melanotaenia splendida inornata), Mariana's hardy‐head (Craterocephalus marianae), delicate blue‐eye (Pseudomugil tenellus), reticulated perchlet (Ambassis macleayi), and purple‐spotted gudgeon (Mogurnda mogurnda) — and the cladocerans — Diaphanosoma excisum, Latonopsis fasciculata, Dadaya macrops, and Moinodaphnia macleayi — was measured under standard conditions in natural creek water. The fishes' 96‐h LC50s for uranium were 1.7 and 1.9 mg/L for 7‐ and 90‐d‐old black‐banded rainbowfishes, 2.66 and 3.46 mg/L for 7‐ and 90‐d‐old chequered rainbowfishes, 1.22 mg/L for Mariana's hardyhead, 0.73 mg/L for delicate blue‐eyes, 0.8 mg/L for reticulated perchlet, and 1.11 and 1.46 mg/L for 7‐ and 90‐d‐old purple‐spotted gudgeon. The cladocerans' 24‐h LC50s for uranium were 1.0 mg/L for Diaphanosoma excisum, 0.41 mg/L for Latonopsis fasciculata, 1.10 mg/L for Dadaya macrops, and 1.29 mg/L for Moinodaphnia macleayi. Larval purple‐spotted gudgeon, reticulated perchlets, and Moinodaphnia macleayi were identified as the most suitable species for toxicity testing.