ISSN 2167-0447
International Journal of Agricultural Sciences ISSN 2167-0447 Vol. 5 (3), pp. 426-434, May, 2015. © International Scholars Journals
Full Length Research Paper
Seasonal variations in the mineral composition of some commercially important fish species of Lake Victoria- Tanzania
*Abdulkarim, B.1, 2, Bwathondi, P.O.J.2 and Benno, B. L.2
1Department of Biology, Umaru Musa Yar’adua University, Katsina State Nigeria
2Department of Aquatic Sciences and Fisheries, University of Dar es salaam, Tanzania. *Corresponding Author. Email: [email protected]
Abstract
Seasonal variations in the mineral compositions of three commercial fish species; Lates niloticus, Oreochromis niloticus, Rastrineobola argentea from Lake Victoria were determined using standard method and procedures. Calcium, potassium, phosphorus, sodium and magnesium were significantly higher (p<0.05) during the wet season, while zinc was significantly (p<0.05) higher during the dry season and no significant differences (p>0.05) in the contents of manganese, copper and iron were observed in L. niloticus. Calcium was higher in the wet season but not significantly different. Potassium, phosphorus, sodium, magnesium and zinc were significantly higher (p<0.05) during the wet season, while manganese and iron were significantly (p<0.05) higher during the dry season and copper was unaffected by the seasons in O. niloticus. Calcium, potassium, phosphorus, magnesium, zinc and iron were significantly higher (P<0.05) in wet season, while sodium, manganese and copper were unaffected by seasons in R. argentea. The three species were found to be good sources of dietary minerals such as calcium, phosphorus, iron, copper and zinc which could be recommended to pregnant women, lactating mothers and infants for normal growth and good health. The high levels of the essential minerals during the wet season indicated that the species could be desirable during this period.
Key words: Fish species, Lake Victoria, mineral composition, seasonal variations, Tanzania.