Accumulation of nitrite in hemolymph of Penaeus japonicus

Abstract

Penaeus japonicus (12.2 to 16.7 g) were exposed individually in 25 ppt salinity seawater to 2, 4, 8 and 20 mg nitrite-N I - I at 20 ± | 0 C; additional trials were run using 5, 20 and 50 mg nitrite-N I -l . Hemolymph nitrite values for control (unexposed) shrimp weighing 12.15 ± 0.62 g and 16.69 ± 2.98 g were 0.152 ± 0.003 and 0.109 ± 0.015 ug nitrite-N ml —1 respectively. Hemolymph nitrite-N of shrimp exposed to 2 mg nitrite-N ml -l was significantly higher (p < 0.01) than that of controls after V2 h exposure. Hemolymph nitrite-N of shrimp increased with increasing seawater nitrite-N. Hemolymph nitrite-N displayed a positive linear relationship with time, whereas seawater nitrite-N was negatively related to time. Shrimp exposed to 2, 4 and 20 mg nitrite-N | -1 accumulated nitrite-N in hemolymph up to 2.291, 6 088 and 25.060 ug ml - respectively, after 16 h, while seawater nitrite-N declined to 0.089, 0.118 and 0.257 mg I