IMMUNOHISTOCHEMICAL STUDY ON THE EFFECT OF CHROMIUM CHLORIDE HEXAHYDRATE SUPPLEMENTATION ON COMMON CARP (Cyprinus carpio L.) FINGERLINGS CHALLENGED WITH Aeromonas veronii AND COLD STRESS

IMMUNOHISTOCHEMICAL STUDY ON THE EFFECT OF CHROMIUM CHLORIDE HEXAHYDRATE SUPPLEMENTATION ON COMMON CARP (Cyprinus carpio L.) FINGERLINGS CHALLENGED WITH Aeromonas veronii AND COLD STRESS

Ahmed Ali Ahmed

Department of Fish Health and Management, Central Laboratory for Aquaculture Research, Agriculture Research Center, Egypt.

ABSTRACT

Cold stress is a main threat on fish in both nature and aquaculture. It can induce oxidative stress in various fish. While the exact role of oxidative stress in cold-caused mortality is still unknown. This study showed that cold exposure induced oxidative stress in common carp fingerlings liver and intestine, which may lead to mortality. The aim of this study was to determine the antioxidant and anti-apoptotic effects of chromium chloride on cold tolerance in common carp fingerlings via assessment of immunohistochemical heme oxygenase 1, caspase 3 expression in liver and intestine. In two months’ feeding trial, fish fed with experimental diets containing chromium chloride Hexahydrate (0, 0.3, 0.5 and 0.6 mg kg-1) during winter. In the current study, the common carp fingerlings which were fed with chromium chloride 0.3 mg kg-1(2^nd group) showed weak caspase 3 expression and strong heme oxygenase 1 expression in both liver and intestine with lower cold-caused oxidative stress and tissues damage, and showed higher cold tolerance. Evaluation of growth performance revealed improved performance parameters than other groups. These results confirmed possible antioxidant, anti-apoptotic and beneficial effects of chromium chloride on common carp fingerlings in a dose dependent manner. Also, the lowest mortality rate detected in 2^nd group insists on antioxidant value of chromium chloride hexahydrate. While, the 4^th group (0.6 mg kg-1) showed strong caspase 3 expression and weak heme oxygenase 1 expression in both liver and intestine. The present study concluded that reduction of oxidative stress will increase cold tolerance and challenge the infections of Aeromonas veronii in common carp fingerlings fish.

Keywords:
common carp, fingerlings, cold stress, Chromium Chloride Hexahydrate.