ABSTRACT

 The realization of the full potential of aquaculture in developing countries has been militated among other factors by essentially expensive fishmeal component of fish feed. As a result, inexpensive novel legumes, which abound in the tropics are being investigated to serve as a replacement for fishmeal. However, these legumes have anti-nutritional factors that militate against their use. Various processing methods to improve the nutritional value of such legumes are therefore being studied. Jackbean (Canavalia ensiforenis (L) DC) is one of such legumes. Experiments were carried out in two phases to study the effect of processing methods and inclusion levels on the general cerfennance of G!orias gariep inns, Heterebranc/s iongi2lis arid catfish hybrid (Ii. long/iBLs x C. gwriepmnus), which are important farmed fish. The first phase of the study involved the response of the three c!ariicl fingerlings to diets containing jackbean seed meal (JLM in a factorial experiment. The factors wme three levels of processing tl,pes and seven levels of substitution of fishmeal by jackbean seed meal in two replications. Data was collected at the commencement of the exeeriment and bPweekly on weight for 56 days. Growth and feed utilization parameters were computed therefrom. Data was also Collected on protein and fat content of the fish at tIne commencement and at the end of the exuerinnenr. in the second phase of the study, haeniatoiogical and ilistological attributes of pa f the three clarfids were investigated in a factorial experiment, The factorsi afrd two levels oferocessing, method and seven levels of sebstitotion of fshnnml been seed meal in two afions. The results showed that of the three c!ariids used (Ce/r:; gaeiepinus Burcheli, I 822; .Hrohranchus /O1i/iIiS VaL 1840 and their hybrid had the best growth response with respect to inclusion levels ofjackbeaa seerl meal. This is fbiiov'ed by