Effects of Sucrose and Some Cryoprotectants on Post-Thaw Sperm Quality (Spermatozoa Motility) and Fertilization of the Mesopotamian Catfish (S. triostegus, H. 1843)

Abstract

Effects of Sucrose and some Cryoprotectants on Post-Thaw Sperm Quality (Spermatozoa Motility) and Fertilization of the Mesopotamian Catfish (S. triostegus, H. 1843)

 Ahmet İlker Mermer¹, Zafer Doğu²

 ¹Şanlıurfa Agriculture and Forestry Provincial Directorate, İmambakır M., 702nd S. No: 6, Haliliye/Şanlıurfa, TÜRKİYE
²Department of Aquaculture, Bozova Vocational School, Harran University, 63850, Bozova, Şanlıurfa, TÜRKİYE

Abstract

 This study was conducted to investigate the effects of cryoprotectants such as sucrose and Dimethyl sulfoxide (DMSO), Methanol, and Methylglycol, along with a glucose diluent, on the post-thaw spermatozoa motility and fertilization of Silurus triostegus larvae in the Atatürk Dam Lake. The 4-5 year old S. triostegus used in the study were caught from the Atatürk Dam Lake in Şanlıurfa province. Post mortem, the examinations of sperm samples taken from S. triostegus through abdominal massage were conducted in the laboratories of the Fisheries Department at Harran University Bozova Vocational School. After the examination, those with 80% and above motility and spermatozoa density of 9.00-14.00 X 10⁹/ml were selected. Sperms were diluted at a ratio of 1/3 with a glucose sperm diluent containing 5% Dimethyl sulfoxide (DMSO), Methanol, or Methylglycol as one of the cryoprotectants, and 50 mM sucrose, 20% egg yolk, and 0.3 M glucose at 4 ºC. The control group sperm diluent used was a glucose sperm diluent containing 10% DMSO, Methanol, or Methylglycol, 50 mM sucrose, 20% egg yolk, and 0.3 M glucose. After the sperm was diluted, it was subjected to equilibration at 4 °C for 10 minutes. After being frozen in liquid nitrogen vapor for 12 minutes, it was stored in liquid nitrogen (-196 °C). After thawing, the spermatozoa motility rate was highest in the DMSO group at 30.00±3.51% (P<0.05). The highest fertilization rate was also found in the DMSO+Sucrose group (20.33±1.52) (P<0.05). In the sucrose control group, fertilized eggs (% 0.0±0.00) could not be detected. The study findings indicate that the glucose sperm diluent containing 5% DMSO and 50 mM sucrose is suitable for spermatozoa motility and fertility in S. triostegus after dissolution.

Key Words: Silurus triostegus, Sperm, Freezing, Sucrose, Cryoprotectant

 *: This study is a part of the master's thesis titled " Effects of Sucrose Added to Diluent In Cryopreservation of Mesopotamian Catfish (S. triostegus, H. 1843) Semen Quality After Thawing " by the first author.