CHANGES IN SUBLETHAL EFFECTS AND LEAD ACCUMULATION IN ACANTHOPAGRUS LATUS UNDER VARIOUS LEAD CONCENTRATIONS AND SALINITIES

Abstract

This study investigated the sublethal concentration of lead and calcium levels in yellowfin seabream juvenile (Acantho-pagrus latus) (4.367 ± 0.470 cm; 1.408 ± 0.478 g) following exposure to a series of lead concentrations at various salinities (0 per mille, 9 per mille, 17per mille, 25per mille and 34per mille). Yellowfin seabream juveniles exposed to 17per mille salinity were the most tolerant to lead. After 96-h, the 50% lethal concentration (LC_(50)) values were 0.33, 1.43, 3.78, 2.32 and 1.46 mg Pb^(2+)/L following exposure to 0per mille, 9per mille, 17per mille, 25per mille and 34per mille salinities, respectively. The 6-, 12-, 24-, 48- and 96-h LC_(50) for fish exposed to 17per mille salinity were 124.67, 33.02, 10.40, 5.15 and 3.78 mg Pb^(2+)/L, respectively. The lead levels in fish body increased with increasing ambient lead concentrations in each acclimated salinity. Fish juvenile exposed to 17per mille salinity had the lowest lead accumulation compared with other exposure salinity exposures. The calcium levels decreased with decreasing salinity exposure and increasing ambient lead concentrations. The fish juvenile exposed to low salinity had a Pb^(2+)/Ca^(2+) ratio that was significantly higher than the high salinity experimental group with the same lead concentration exposure. In conclusion, the lead toxicity and accumulation of the fish juvenile were affected by salinity concentrations.