Physiological Responses of African Catfish (clarias gariepinus) to Water-Borne Ferric Iron: Effects on Thyroidal, Metabolic and Hydromineral Regulations
Keywords:Catfish, Clarias gariepinus, Ferric Iron, Osmoregulation, Thyroid, Fish.
AbstractWith a view to understand the mechanism associated with the tolerance of excess water-borne iron, thyroidal, hydromineral and metabolic responses were studied in the freshwater African catfish Clarias gariepinus after exposing them to nominated concentrations (6.2 and 62 Î¼M) of ferric iron [Fe(III)] for 48 hr. Plasma triiodothyronine (T3) and thyroxine (T4) concentrations and the indices of metabolic and hydromineral regulations were analyzed in the iron-treated fish. Plasma T4 (P<0.001) and T3 (P<0.05) decreased in catfish after Fe(III) treatment. On the contrary, an elevated (P<0.001) plasma T4 occurred in the fish kept for recovery in clean freshwater after iron-treatment. A significant (P<0.01) hyperglycemia was observed in 62 Î¼M Fe(III)-treated fish whereas plasma urea concentration remained unchanged. Ouabain-dependent Na+, K+-ATPase activity increased (P<0.05) in the branchial tissue of 6.2 Î¼M iron-treated fish but decreased in the renal (P<0.05), intestinal (P<0.01) and hepatic (P<0.01) tissues. Plasma Na+ and PO42- decreased (P<0.05), whereas plasma K+ and Ca2- increased (P<0.05) after Fe(III) treatment. Our results indicate that despite the modification in the metabolic and hydromineral regulation, water-borne Fe(III) suppresses the thyroid activity, and withdrawal of Fe(III) activates the thyroid function in African catfish, thus supporting the hypothesis that thyroid hormones are involved in iron handling in fish.
Download data is not yet available.
Metrics Loading ...
How to Cite
Subhash Peter, M. C., Leji, J., Rejitha, V., Ignatius, J., & Peter, V. S. (2008). Physiological Responses of African Catfish (<i>clarias gariepinus</i>) to Water-Borne Ferric Iron: Effects on Thyroidal, Metabolic and Hydromineral Regulations. Journal of Endocrinology and Reproduction, 12(1), 24–30. Retrieved from https://informaticsjournals.com/index.php/jer/article/view/2081