Some physiological and nutritional responses of common carp Cyprinus carpio juveniles to osmotic stress

Salinity Liver enzymes Plasma protein Growth FCR

Authors

  • Fatima A.M. Sultan Department of Fisheries and Marine Resources, College of Agriculture, University of Basrah, Basrah, Iraq.
  • Riyadh A. Al-Tameemi Department of Fisheries and Marine Resources, College of Agriculture, University of Basrah, Basrah, Iraq.
  • Salah M. Najim Department of Fisheries and Marine Resources, College of Agriculture, University of Basrah, Basrah, Iraq.
October 25, 2023

Downloads

The effect of salinity (<1, 7, and 15 ppt) on some physiological and nutritional parameters of common carp (Cyprinus carpio) juveniles was examined in two trials. In the first trial, the activity of the common liver enzymes (alkaline phosphatase ALP, Aspartate transaminase AST, and Alanine transaminase ALT) in the blood serum, and total plasma protein level on the 1st, 7th, and 14th day of exposure, using 90 fish (14.05±2.01g) were studied. In the second trial, the growth and feed efficiency performance (weight gain WG, relative growth rate RGR, specific growth rate SGR, and feed conversion ratio FCR), and apparent digestibility coefficients ADCs of dry matter, nutrients, and energy were investigated during ten ten-week rearing period using another 90 fish (15.71±1.59 g). The results showed that the activity of the ALP was increased significantly (P?0.05) with increasing salinity on the 1st day, and continued to the following 7th and 14th day periods. AST in 7 and 15 ppt showed significantly (P?0.05) higher activity levels compared with 1 ppt on the 1st day, similar differences were found on the 7th and 14th day for 15 ppt, but not for 7 ppt during the same periods. ALT exhibited significantly (P?0.05) higher activity in 7 and 15 ppt relative to <1 ppt during all periods. Total plasma protein fluctuated slightly (P>0.05) on the 1st and 7th day and decreased significantly (P?0.05) in 15 ppt only on the 14th day. Significantly (P?0.05) better specific growth rate SGR and feed conversion ratio FCR were observed in the lowest salinity (<1 ppt) while the worst in the highest (15 ppt). The ADCs of dry matter, nutrients, and digestible energy were decreased significantly (P?0.05) with increasing water salinity.