Seminal composition and semen quality are the important determinants in assessing the reproductive performance of different fishes. This study was carried out to evaluate the seminal composition and sperm quality of Barbonymus gonionotus. The seminal plasma contained 17.2 ± 0.34 mmol/l, 20.9 ± 0.48 mmol/l, 0.72 ± 0.04 mmol/l, 3.8 ± 0.2 mmol/l, and 1.49 ± 0.02 g/dl of Na+, K+, Ca++, Mg++, and total protein, respectively. The physical spermatological parameters, such as sperm volume, sperm motility, motility duration, sperm density, osmolality, and pH values were 1.55 ± 0.15 ml, 89 ± 2%, 391.9 ± 8.5 s, 2.8 ± 0.2 × 1010 /ml, 400.6 ± 5.1 mmol/kg, and 8.75 ± 0.10, respectively. In correlation matrix, the K+ (R2 = 0.39, P < 0.01) and Ca++ (R2 = 0.27, P < 0.05) ions and osmolality (R2 = 0.29, P < 0.05) showed significant positive correlations with sperm motility. Similarly, fertilization rate significantly influenced by sperm motility (R2 = 0.26, P < 0.05) and K+ (R2 = 0.30, P < 0.05) and Ca++ (R2 = 0.26, P < 0.05) ions. Also, osmolality significantly and negatively correlated with Mg++ (R2 = 0.33, P < 0.05) and sperm motility duration (R2 = 0.28, P < 0.05). Therefore, based on this results, it can be concluded that seminal plasma ions, K+ and Ca++ and osmolality are the key factors for the determination of sperm quality of silver barb, and these parameters could be considered during standardization of artificial fertilization or cryopreservation technique of silver barb spermatozoa.
Keywords: Barbonymus gonionotus; Osmolality; Plasma ion; Silver barb; Spermatozoa motility.