Majallah-i ̒Ilmī-i Shīlāt-i Īrān (Jan 2008)
WATER OSMOLARITY EFFECT ON SPERMATOCRIT AND ITS RELATIONS TO SPERMATOZOAN COUNT IN MALE BREEDERS OF RUTILUS FRISII KUTUM IN THE SOUTH-WESTEN OF THE CASPIAN SEA
Abstract
The relationship between morphometric characteristics, motile spermatozoan percentage and sperm motility duration among male breeders of Rutilus frisii kutum in four different rivers (Shirud, Khoshkrud, Sefidrud and Chalevand) of the southwestern part of the Caspian Sea and water osmolarity, pH and temperature in four region of each river (estuary, river entrance to sea, artificial reproduction site and upstream) were considered. The mean motility duration time was 37.2±4.2, 41.4±3.9, 52.9±2.1 and 47.8±3.4 in the four rivers respectively. Also, the percentage of motile cells was found to be 49±4.1, 58.2±6.8, 74±4.8 and 68.1±5.9% for the rivers respectively. The mean osmolarity, temperature and pH were 71.7±66, 62.5±85.5, 40.2±34.2,36.7±34.4 mOsml/l, 14, 15, 13.6±0.2,14oC and 7.6±0.1, 7.2±0.1, 7.4±0.1 and 7.2±0.1 respectively. Our findings showed that there is a positive relationship between motile spermatozoan percentage and duration of motility. With the decrease in river water osmolarity from estuaries up to the river upstream, the motile spermatozoan. percentage and their duration increased. According to anadromous behaviour of the fish, with increasing distance from artificial breeding sites toward river upstream, quantity of spermatozoa and spermatozoan activity increased enhancing success in fertilization attempts.
