Blood biochemistry fluctuations as influenced by feed provision in juvenile Snow trout (Schizothorax zarudnyi)

This study aimed at determining blood biochemical parameters with potential diagnostic value to assess the nutritional status for healthy Snow trout, Schizothorax zarudnyi. For this purpose, three treatment groups of Snow trout (average weight, ۶۵.۹±۵.۳ g) were kept unfed for ۲۴ h, ۷ and ۱۴ days. During the experiment, a natural photoperiod was adopted, water temperature was maintained at ۲۳.۲±۱.۱ °C, pH at ۷.۸±۰.۲, dissolved oxygen at ۷±۰.۴ mg L-۱ and ammonia concentration was kept around zero mg L-۱. Fish in all treatment groups were fed twice a day, to apparent satiety. At the end of the trial, the levels of glucose; triglyceride; cholesterol; total protein; inorganic phosphorus; calcium; magnesium; triiodothyronine (T۳); thyroxin (T۴); alkaline phosphatase (ALP); aspartate aminotransferase (AST); Alanine aminotransferase ( ALT ) and lactate dehydrogenase (LDH) were determined using standard clinical methods. The results showed that glucose (۷۱.۸±۶.۶۴-۱۳۸.۶±۱۳.۰۲ mg dl-۱), AST (۶۳.۵۳±۱۲.۱۷-۱۳۰.۴۱±۲۳.۰۴Ul-۱) and T۴ (۶.۴۶±۰.۸۸-۱۱.۶۹±۱.۱۶ ng ml-۱) levels were significantly affected by the starvation period (p<۰.۰۵). T۳ levels remained relatively stable during the first week of starvation (۲.۳±۰.۲۵-۲.۳۹±۰.۳۱ ng ml-۱) and then significantly decreased (۱.۷۷±۰.۱۶ ng ml-۱) in the second week of starvation (p<۰.۰۵). Triglycerides levels increased during the first week of starvation (۱۴۷.۴۰±۱۶.۶۲ to ۱۹۹.۳۱±۳۱.۴۲ mg dl-۱) and decreased significantly (p<۰.۰۵) in the second week (۱۶۳.۷۰±۲۴.۶۳ mg dl-۱). These results suggested that in healthy Snow trout juveniles, glucose, AST and T۴ levels are responsive to starvation.

Keywords:

Blood biochemistry , Thyroid hormone , Enzymes activity , Schizothorax zarudnyi , Starvation