Evaluation of Semen Quality Indices in Cultured and Wild Broodstock of Clarias gariepinus: Implications for Aquaculture Reproduction and Broodstock Management

Abstract

Abstract

African catfish (Clarias gariepinus) is an economically important aquaculture species in Nigeria, and sustainable hatchery production depends partly on the availability of suitable male broodstock and good-quality semen. This study compared selected semen quality parameters of cultured and wild male C. gariepinus to assess differences associated with broodstock source. Six sexually mature males, comprising three (3) cultured and three (3) wild individuals, were examined. Semen was obtained through testicular extraction following dissection. The evaluated parameters included gonad weight, gonadosomatic index (GSI), milt volume, sperm motility, sperm concentration, sperm viability, sperm morphology, and semen pH. Descriptive comparisons indicated that wild broodstock had higher mean gonad weight (5.33 ± 1.20 g), milt volume (2.72 ± 0.10 mL), and sperm concentration (5.82 ± 0.23 × 10¹⁰ sperm cells mL⁻¹) than cultured broodstock, which recorded 3.50 ± 0.76 g, 2.58 ± 0.17 mL, and 5.56 ± 0.11 × 10¹⁰ sperm cells mL⁻¹, respectively. The percentage of active spermatozoa was also numerically higher in wild fish (69.17 ± 7.77%) than in cultured fish (63.33 ± 14.00%). Semen pH was 7.00 in both groups. Wild broodstock recorded a higher mean proportion of morphologically normal spermatozoa (88.00 ± 2.16%) than cultured broodstock (76.80 ± 12.95%). The reported statistical analysis, however, indicated no significant differences between the groups (P > 0.05). Qualitative characteristics, including semen colour, viscosity, and liquefaction time, varied between the two sources. These findings indicate that both cultured and wild broodstock produced measurable quantities of testicular semen with broadly comparable characteristics under the conditions investigated. Further studies involving larger numbers of broodstock and controlled fertilisation trials are necessary to determine whether the observed differences influence fertilisation success, hatchability, and larval performance. This study provides preliminary information that may contribute to broodstock evaluation and management in African catfish aquaculture.