The spontaneous reproduction of tilapia : an opportunity or a handicap for the development of African aquaculture ?
1996
Lazard, Jérôme | Legendre, Marc
The year-round, spontaneous and continued reproduction of tilapia in captivity was initially regarded as an unexpected asset for African aquaculture development, but it was quickly found to be a serious handicap when farming the fish in ponds due to the resulting population. Various techniques have overcome this obstacle. The reproductive efficiency of tilapia has advantages and disadvantages for the supply of fry to fish farmers. Among the advantages is the possibility for fish farmers to produce their own fry; among the disadvantages is the difficulty to control the broodstock quality. The low number of eggs in each spawning requires the use of a large number of broodstock and the asynchrony of spawnings makes the simultaneous production of large quantities of graded fry difficult. Finally, the control of undesirable reproduction in farming involves the use of monosex populations. These issues are analyzed and discussed in relation to development strategies, microeconomics and the identification of research themes that can be developed to improve the different options. The data for three species of tilapia (Oreochromis niloticus, Sarotherodon melanotheron and Tilapia guineensis) are compared to the data for two species of African catfish of the family Clariidae (Clarias gariepinus and Heterobranchus longifilis) that require induced reproduction techniques, but are far more fertile. (Résumé d'auteur)
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