Effect of Sperm Sac (Testis) in Cryopreservation Protocol of Milt (Spermatozoa) of <i>Clarias Gariepinus</i>

Abstract

This study was carried out to assess the adequacy of cryopreservation protocol of milt (spermatozoa) of Clarias garipenus , using the sperm sac (testis) intact with the objectives of evaluating the milt for percentage live, motility and mass activity for a period of seven days at -20°C. Semen samples (milt) were collected from mature male broodstocks of Clarias gariepinus of 14 months old and weighing 1.5 kg. There were two groups comprising test and control groups. Test group comprising of the sperm sac was dipped in Na-Citrate and placed in a properly labelled container and preserved at -20°C while control group comprised of milt extended in Na-Citrate dispensed into seven insulin syringes, properly labelled and stored at 4°C. These were observed for a period of seven days and percentage motility, percentage live as well as mass activity of spermatozoa of these samples were recorded. Student’s t test was used in analyzing the data. Results showed statistically significant difference (p<0.05) in motility, percentage live and mass activity between test and control groups, with test group showing mean percentage motility, percentage live and mass activity of 24.29±76%, 24.29±76% and 1.14±1.8 respectively while the control showed values of 48.57±65%, 48.57± 65% and 2.0±1.0 respectively. It was concluded that use of the sperm sac at -20°C can only be adopted within three days of collection from the fish. It was recommended that farmers adopt the protocol only for a short term period to eliminate the frustration of artificial spawning failure due lack of good semen to complete the synchronous reproductive process.