Evaluation of induced spawning on oocyte characteristics and serum biochemistry of African catfish (Clarias gariepinus)

The effects of induced spawning using salmon gonadotropin-releasing hormone analogue (GnRHa) and domperidone proprietary drug (ovaprim) injected (0.4 ml/kg) intramuscularly on oocyte characteristics, sex hormones, thyroid hormones, and serum biochemical response were evaluated at 0, 12, 24, and 36 h post-induction. Twenty-eight 8 months old female Clarias gariepinus were used. At the designated hour, 7 of these fish were randomly selected for sampling. The response to the induction of spawning using ovaprim was time-dependent. The onset of response was observed from 12 h for increase in GSI, oocyte flotation, and oocyte diameter. The mean diameter of the different categories of the oocytes was significantly higher than those of the control at 24 h post-induction. Spawning was associated with a significant increase in serum estrogen and calcium level from 12 h post-induction. Furthermore, induction of spawning resulted in significantly higher serum levels of cholesterol, testosterone, and triiodothyronine as well as significantly higher activities of ALT and AST at different time-points. However, the BUN and serum levels of chloride and sodium were significantly lower compared with the control. From this study, the time for stripping of roe for optimal spawning outcome may be between 12 and 24 h. © 2019, Springer-Verlag London Ltd., part of Springer Nature.