Effects of Common Hatchery Practices on Artificial Fertilization Success in African Catfish (Clarias gariepinus): Sperm Activation Media and Post-stripping Egg Storage Duration

Abstract

In African catfish hatchery systems, post-stripping egg storage duration may vary among operators, and different additives are sometimes used empirically for sperm activation during artificial fertilisation. This study assessed the effects of post-stripping egg storage duration and sperm activation media on sperm motility characteristics and fertilisation success in C. gariepinus. Three egg storage durations (11, 38, and 71 min) and four sperm activation media (borehole water, sugar–salt borehole water, sugar borehole water, and saline borehole water) were evaluated with three replicates. Regarding sperm motility characteristics, borehole water resulted in the highest motility rate (83.3 ± 5.8%), whereas salt-containing activation media produced the lowest values (10.0 ± 8.7% and 4.0 ± 1.7%). However, no significant relationship was observed between sperm motility parameters (motility rate, duration, and intensity) and fertilisation rate (P > .05). Egg storage duration had a significant effect on fertilisation rate, regardless of the sperm activation medium used. Fertilisation rates decreased progressively with increasing storage duration, with the highest values recorded after 11 min of storage (87.7 ± 3.2 - 95.0 ± 1.0%), intermediate values after 38 min (78.67 ± 2.08 - 85.67 ± 4.93%), and the lowest values after 71 min (70.67 ± 0.58 - 78.00 ± 3.00%). Overall, egg storage duration explained a greater proportion of the variation in fertilisation success than sperm activation medium. These findings provide scientific support for optimising artificial fertilisation practices in African catfish hatcheries. Further studies integrating hatching success and larval survival are needed to evaluate the effects of these practices on fry production performance.