Effects of a legume (Paseolus mungo) substituted diets on the development and protein content of the gonads of O. niloticus (L.)

Abstract

Substitution of fish meal in practical diets with readily available plant matter is commonly practiced in aquaculture industry in many developing countries. Leguminous plant products are the most commonly used plant ingredients. Oreochromis niloticus (L.) of two length groups (i.e., 4.0 - 6.0 cm and 7.5 - 10.5 cm) were fed twice daily with a control diet (CD) and two test diets, TD1 and TD2 containing 30%, 20% and 10% fish meal respectively, and total protein content of 28% by dry weight. The two test diets TD1 and TD2 contained 16% and 39% of Paseolus mungo, by dry weight. Sex ratio of experimental fish were maintained at 2: 1,9 After four weeks of feeding, gonads of experimental fish were removed for histological studies and chemical analysis. Ovaries of TD2 fed fish contained the largest vitellogenic oocytes while those of TD1 fed fish had the highest protein content. Testis of all three diets fed fish contained spermatogonia, spermatids and spermatozoa.