Gynogenesis of Pengba Fish Osteobrama belangeri (Valenciennes, 1844): Comparative Analysis on Use of Conspecific and Heterospecific UV‐Irradiated Sperm

Gynogenesis has wide application in genetic improvement program for the generation of inbred line, mapping population, monosex population, and conservation. In the present study, embryonic development in gynogenesis of Pengba (Osteobrama belangeri [O. belangeri]) was analyzed to evaluate the efficacy of using conspecific and heterospecific sperm. For the selection of suitable sperm donor, three heterospecific males (Tilapia, Rohu, and Java barb) were experimented with no UV irradiation and thermal shock. The result showed high fertilization rate in case of Rohu and Java barb thus, they were omitted from further gynogenesis, in view of possibilities of producing hybrid offspring. For gynogenesis study, three experiments were conducted; first, conspecific as well as heterospecific sperm (Tilapia) were used to fertilize Pengba eggs (UV-irradiated sperm of Pengba and thermal shock to maintain diploidy) and the fertilization, hatching and survivability rates were recorded as 18%-20%, 5%-6%, and 2%-3%, respectively. Fertilization rate in Tilapia sperm without UV irradiation and thermal shock and UV-irradiated sperm of tilapia and thermal shock to maintain diploidy experiments was recorded as 4%-5%. However, hatching did not occur in either of the cases. Our results form the first report of gynogenesis in O. belangeri using conspecific and heterospecific sperm, which will be helpful in its genetic stock improvement programme and ensure conservation of native stock as well as better production in aquaculture.