In freshwater and aquaculture contexts, hybridization between the Oreochromis species has recently increased in frequency. The purpose of this study was to assess the development of the gonadal / gametes in crossings between hybrids of Oreochromis niloticus and Oreochromis andersonii crossed (X) with hybrids of Oreochromis niloticus and Oreochromis macrochir. Nine males and eighteen female brooders, weighing an average of 180±0.32g, were first conditioned by keeping the males and females apart for a month. They were then fed a commercial diet at a body weight of 5%. In a completely randomized setup, the sexes were paired in a 1 x 2 m hapa at a 1:1 sex ratio and the process was repeated three times.
The results indicate that the crosses between the hybrids did not breed after mixing the sexes for a period of six weeks. When subjected to laboratory analysis, three males out of nine had partial gonadal development, whilst six males had no gamete development and a single male developed full gonads. Female brood stock did not develop any gonads. The study demonstrates that the development of gametes in Oreochromis hybrids is unpredictable.
The results points to hybrids fecundity rate reduces with generation and sterility sets in, in the subsequent generations.
Therefore, this study advises farmers not to consider choosing brood stock from such batches from the generation of hybridization.
It is imperative to regularly replace broodstock in aquacultural facilities as hybrids are produced to enhance growth rates and for consumption thereby increasing economic productivity.