Effect of Temperature on Acute Toxicity of Nitrite to Meagre, Argyrosomus regius (Asso, 1801)

Meagre, Argyrosomus regius, is a candidate marine fish species for aquaculture diversification, presenting a high economic value in the Mediterranean. Tolerance of juvenile meagre to nitrite (NO2-N) was determined relating to temperature. Fish (3.2 +/- 0.6g and 5.4 +/- 0.9cm) were exposed to different NO2-N concentrations in a series of acute toxicity tests by the static renewal method at three temperatures (18, 22, and 26C) at a pH of 8.0. Low temperature clearly increased tolerance to NO2-N (P<0.05). The 96-h median lethal concentration (LC50) values of NO2-N were 177.63, 139.55, and 49.61mg/L, at 18, 22, and 26C, respectively. The safe levels of NO2-N for juvenile meagre were estimated to be 17.7, 13.9, and 4.9mg/L at 18, 22, and 26C, respectively (P<0.05). This study indicates A. regius is more sensitive to nitrite than other marine fish species cultured in the Mediterranean.