The prolonged starvation has many effects on the physiological and morphological processes in fish and interferes them with the ability to absorb nutrients and caloric intake. The aim of present study was to investigate the effect of long-term starvation and posterior dietary administration of commercial synbiotic consisting fructoligosaccharide (FOS) which used in combination with Enterococcus, Lactobacillus, Bifidobacterium and Lactococcus spp. for evaluation on some blood biochemical parameters and histological characteristics of common carp liver. Experimental fish after 5 months starvation period were subjected to the following feeding protocols: continuous starvation until 60 day (ST), re-feeding (FS) with dry composed diet (Aqua 1032 Swim) and refeeding with composed diet and synbiotic (FSS) for the following 60 days. Blood samples were used for analysis of the following plasma parameters: total protein, albumin, globulin, urea, creatinine, cholesterol, AST, ALT, glucose and serum for thyroid hormones. Histology analyses were performed on the carp liver samples. During the experimental period, fasting and refeeding were influenced significant on studied biochemical parameters, except glucose and urea. Also, the statistically largest (P <0.001) difference was observed in albumin and cholesterol values after refeeding. Our results reveal the changes in values of biochemical parameters during long-term starvation and refeeding with synbiotic and indicate signs of structural alterations of the liver in common carp.

The acute phase response (APR) is a nonspecific reaction of fish to disturbances in homeostasis. The aim of present study was to investigate quantitative changes that occur in the concentration of acute phase proteins (APPs) in the blood of commercial size common carp (Cyprinus carpio L.) exposed to organophosphate insecticides within the month of April during ameliorative activities. Parameters examined were fibrinogen (Fib), ceruloplasmin (Cp) as a positive APPs and albumin (Alb) as a negative APP. Histological sections of the hepatopancreas and kidneys from 25 fish have been examined. The hepatopancreas was chosen for this investigation as it is the primary site of acute phase protein synthesis. APP parameters plasma fibrinogen (P<0.05) registered a significantly increased and albumin (P<0.05) exhibited statistically declined in treated group. Based on the data acquired in this study, it was concluded that, the carp do not exhibit a strong APP synthesis during the early stages of an APR after spraying with organophosphate insecticides. The results from this study show that the concentrations of fibrinogen are not significantly increase as well as the levels of ceruloplasmin remained unchanged.