Comparative study on spermatological parameters and seminal plasma composition of Labeo rohita strains from Tamil Nadu, India

The fertilization success and seed quality of Labeo rohita from different locations show wide variation. The important reason for these variations is sperm quality. Spermatological parameters are considered to be the deciding factors of sperm quality. The present study envisages delineating the strain-specific variations in spermatological parameters and seminal plasma composition of L. rohita from three different locations (Manimuthar, Thanjavur and Mettur) of Tamil Nadu.

In the present study conducted during 2019, milt samples were collected from three different strains of Labeo rohita. The samples were analyzed for the spermatological parameters such as pH, volume, sperm density, spermatozoa motility and seminal plasma composition (Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl-) following standard protocols and the statistical comparisons were made.

Among the strains, the spermatozoa of Thanjavur strain exhibited best performance with highest motility duration (82.33±6.03 s) (p<0.025) and sperm density (2.526±0.25 × 10⁹ cells/ml). With regard to seminal plasma composition, the concentration of Na⁺ (113.64±4.97 mmol/L) and K⁺ (149.91±1.67 mmol/L) was the highest in Thanjavur strain. Mettur strain exhibited highest Ca²⁺ (1.24±0.06 mmol/L) content (p<0.01) besides its lowest Na⁺ concentration (51.28±3.52 mmol/L). The results revealed a significant correlation between ionic composition of seminal plasma and sperm motility. The increased motility duration in Thanjavur strain was due to increased K⁺ concentration. A synergistic effect of ions in controlling sperm motility was also observed as the higher Ca²⁺ concentration could sustain lowered Na⁺ concentration in Mettur strain.