Serum levels of macro minerals (trace elements) in some local fresh water fishes during breeding period

Abstract

The role of macro minerals (trace mineral elements) in biological systems has been described in several animals. However, the knowledge in fish is mainly limited to iron, copper, manganese, zinc and selenium as components of body fluids, cofactors in enzymatic raactions, structural units of non- enzymatic macromolecules, etc. Investigations in fish are comparatively complicated as both dietary intake and water borne mineral uptake have to be considered in deterging the mineral budgets. The importance of trace minerals as essential ingredients in diets, although in small quantities, is also evident in fish. Serum levels of some important macro minerals such as sodium (Na+), potassium (K+), calcium (Ca),phosphorous and magnesium (Mg) have been studied in four freshwater fishes collected from a local market as these fishes are edible fishes and are extensively purchased by the local public in the Kalaburagi city. These minerals play significant role in accumulation of nutrients, osmoregulation, homeostasis and other physiological activities of the fish particularly during breeding period. The blood serum level of these macro minerals determined in four local fresh water fishes are, Labeo rohita, Catla catla, Cirrhana mrigala and Pangusius becocurti. The results of macro mineral concentration level were compared among them and it is indicated that there is difference. The serum sodium level in all the four types of fishes is at higher level in comparison to other minerals. The variation and the order of concentration of minerals in all four types of fishes found to be as: sodium> potassium> phosphorous> calcium> magnesium. The aquatic body in which these fishes are harbored has required mineral concentration needed for various physiological activities in the process of nutritional absorption, osmoregulation and homeostatic mechanisms. Hence, the levels of blood serum macro minerals found in these fishes are though lesser during breeding period in the present study are considered to be in normal levels as reported in other fishes.