Jc. Chen et Sy. Cheng, CHANGES OF OXYHEMOCYANIN AND PROTEIN-LEVELS IN THE HEMOLYMPH OF PENAEUS-JAPONICUS EXPOSED TO AMBIENT NITRITE, Aquatic toxicology, 33(3-4), 1995, pp. 215-226
The concentrations of oxyhemocyanin, protein and urea in the hemolymph
, and ammonia-N excretion of Penaeus japonicus (15.08 +/- 1.56 g) were
examined, after the shrimp had been exposed individually in 30 ppt to
0.01 (control), 5.12, 10.46, 20.57 and 50.86 mg/l nitrite-N at 25 deg
rees C for 24 h. Accumulation of nitrite-N and urea-N in the hemolymph
, and ammonia-N excretion of shrimp increased with increased ambient n
itrite-N over the entire range. Nitrite-N uptake occurred, and increas
ed with increased ambient nitrite-N in the range of 5.12-50.86 mg/l. E
xposure of P. japonicus to elevated nitrite-N-affected nitrogen metabo
lism, and decreased the oxyhemocyanin and the ratio of oxyhemocyanin/p
rotein. It is suggested that nitrite incorporated into the hemolymph o
f penaeids may decrease the oxygenation state of the hemolymph, and de
crease the fraction of oxyhemocyanin.