Hemolymph osmolality, acid-base balance, and ammonia excretion of Penaeus japonicus bate exposed to ambient nitrite

Penaeus japonicus Bate (11.43 +/- 1.41 g) were exposed individually in 30 ppt seawater to 0.01 (control), 0.07, 0.37, 0.72, and 1.43 mmol/L nitrite-N at 25 degrees C for 24 h. Concentrations of hemolymph osmolality, acid-base balance, and ammonia-N excretion were examined. An increase in the ambient nitrite concentration significantly increased nitrite uptake, ammonia excretion, and hemolymph PO2, and decreased hemolymph pH, PCO2, TCO2, HCO3-, and osmolality. It is concluded that incorporation of nitrite-N in the hemolymph of P. japonicus following exposure to ambient nitrite-N affects its acid-base balance, ammonia excretion, and osmoregulation.