Rearing in hypersaline inland ground saline water affect growth and osmoregulatory responses of Common carp (Linnaeus 1758)

Abstract

Abstract To examine the culture suitability of common carp in inland saline by evaluating the growth as well as osmoregulatoryresponses,one hundred eighty Cyprinus carpio juveniles (15.9 ± 0.05g) were randomly distributed in four experimental groups in triplicate following completely randomiseddesign T1(0 ppt), T2 (5 ppt), T3 (10 ppt) T4 (15 ppt). Complete mortality occurred in the group reared at 15 ppt within 7 days. Further, with three groups (salinities: 0, 5, 10 ppt)the experiment was continued for 60 days.The weight gain percentage, specific growth rate, protein efficiency rateand feed efficiency ratiowere lowest (P<0.05)in the groups reared at 10 ppt compared to 0 and 5 ppt. Similarly, highest expression of IGF-1was observed at 0 ppt followed by 5 ppt. Serum ions concentration as well as serum and water osmolality was increased significantly at 10 ppt compared to 0 ppt and 5 ppt. Na,K-ATPase alpha subunitwas non-significantly increased from 0 to 5 ppt but its value was significantly higher at 10 ppt. Serum glucose and cortisol were independent on salinity (0-10 ppt). the studies revealed that common carp can tolerate salinity upto 10 ppt, however at 5 ppt highest salinity upto which species can grow without any adverse effect on their internal physiology was found and suitable for growth.