Improving sperm quality of large South American catfish using trehalose-based activating solutions

Leiarius marmoratus, Zungaru jahu, and Phractocephalus hemioliopterus are large South American catfish species of high commercial and environmental value. This study aimed to evaluate the effect of trehalose solutions at different concentrations (25, 50, 75, and 100 mM), used as activating media, on sperm kinetic parameters over time (10 to 60 seconds post-activation). Sperm from L. marmoratus (n = 4), Z. jahu (n = 2), and P. hemioliopterus (n = 4) were collected following hormonal induction. A pooled sperm sample per species was activated with trehalose solutions and distilled water (control). Sperm kinetics were assessed using a Computer Assisted Sperm Analyzer (CASA). Mean sperm volumes were 0.78 ± 0.17 mL for L. marmoratus, 0.5 ± 0.2 mL for Z. jahu, and 2.4 ± 0.9 mL for P. hemioliopterus. In L. marmoratus, 50 and 75 mM trehalose solutions significantly improved motility duration, percentage, velocity, and progression compared to water. Similarly, 50 and 75 mM trehalose prolonged Z. jahu sperm motility, particularly after 40 seconds, although no significant effect was observed in the first 30 seconds. For P. hemioliopterus, higher trehalose concentrations (75 and 100 mM) increased sperm velocities and progression while reducing motility; thus, distilled water and lower trehalose concentrations (25 and 50 mM) solutions proved more effective. Trehalose solutions containing 50 and 75 mM are recommended for L. marmoratus and Z. jahu sperm activation. For P. hemioliopterus activating sperm, distilled water is better indicated, and trehalose solutions containing more than 50 mM should be avoided.