Effect of salinity stress on neurosecretory cells, protein and free amino acid content and rate of ammonia excretion of the prawn Penaeus indicus H Milne Edwards

Stress induced changes resulting from salinity exposure are sought in the neurosecretory cells of different neuroendocrine centres, in protein and free amino acid content in haemolymph, muscle. and hepatopancreas, and in rale of ammonia excretion in the prawn Penaeusindicus. Prawns acclimated to low saline medium (S . 10%0) when uansferred to rugh saline medium (5 .. 4Q%.o) showed liule change in their neurosecrelOry cell histologY'. However, protein and free amino acid content in haemolymph. muscle. and hepatopancreas increased considerably. Simultaneously, the rate of ammonia excretion was reduced. Prawns acclimated 10 high salinity medium when transferred 10 low salinity exhibited changes in the above parameters in reverse to those findings in the former experiment. The probable reasons for such changes are discussed