Effects of constant and changing water temperature on sperm quality of the endangered Çoruh trout, Salmo coruhensis

Abstract

ABSTRACT In this study, the cumulative influence of male acclimation temperature on sperm quality of the Çoruh trout Salmo coruhensis was compared during the sperm production period. Broodstocks were kept in constant (12.8ºC), and changing (8.4ºC to 12.8ºC) water temperature using well water and stream water until first spawning and sperm quality traits were compared. 20 individuals three-year-old males with a mean weight of 2147 ± 647 g and a mean length of 56 ± 2 cm were used for the two groups in this study. Total sperm motility (%), progressive motility (%), sperm volume (ml), seminal plasma pH, osmolality (mOsm/kg), spermatozoa concentration (cells/ml), and spermatozoa duration (sec) were investigated. Total sperm motility (96.40% ± 25.06) and sperm volume (13 ± 5.97 ml) in the stream water group were significantly higher than in the well water group (82.68% ± 11.52 and 6.2 ± 2.48 ml) (P < .05). These results indicate that S. coruhensis prefers changing and colder stream water during the sperm production period to produce a good quality gamete.