l-Arginine Improves Sperm Motility in Threatened Coruh Trout Salmo coruhensis (Teleostei: Salmonidae)

l-arginine is a versatile amino acid and precursor of nitric oxide that provides protection for preventing free radical damage. Herein, experiments were designed to clarify the effect of l-arginine supplementation on the sperm motility of a threatened trout, Coruh trout Salmo coruhensis. Activation solution was supplemented with levels of 0 mM (Control), 2 mM, 4 mM, and 8 mM l-arginine, and motility and survival of sperm cells were assessed. The selected concentrations were determined according to results of our preliminary experiments. The sperm motility rates at l-arginine concentrations of 0, 2, 4, and 8 mM were 73.33 ± 5.77%, 76.67 ± 5.75%, 80.01 ± 0.01%, and 90.00 ± 0.05%, respectively; notility durations were 21.67 ± 2.08, 32.33 ± 3.79, 32.67 ± 1.15, and 37.00 ± 6.38 s, respectively. Significant effect of l-arginine supplementation was determined on the percentage and duration of motile spermatozoa (p < 0.05). The maximum increment was evoked at the greatest concentration (8 mM). Here, we showed that l-arginine supplement can improve sperm motility of S. coruhensis.