RESUMO
BACKGROUND: In order to preserve the genetic diversity of cichlid fish in gene banks, it is necessary to use certain extenders to maintain the integrity of spermatozoa cells during cooling. OBJECTIVE: To evaluate the effects of different extenders on the quality parameters of cooled semen of Geophagus brasiliensis. MATERIALS AND METHODS: Semen samples were collected from seven adult fish and diluted with five extenders: Beltsville Thawing Solution (BTS™), Hanks' Balanced Salt Solution (HBSS), Tris-glucose, Ginsburg's Fish Ringers, and Phosphate buffered Saline. All parameters were evaluated in fresh semen samples and after cooling at 4°C at 0, 24, 48, and 96 h to evaluate cell viability (membrane integrity, DNA, and mitochondrial functionality) and motility rate and weather motility. RESULTS: The BTS and Tris-glucose resulted in the best outcomes (P<0.05) in terms of membrane integrity assessments (35.1% and 30.9%, respectively), DNA integrity (71.6%; 75.7%), mitochondrial function (26.9%; 28.0%) and motility rate (8.6%; 8.6%), respectively, for semen cooled to 4°C for 96 h. However, the 48-h period motility after cooling in BTS was superior to all other treatments. CONCLUSION: BTS and Tris-glucose can be considered as the best extenders for the cold storage of Geophagus brasiliensis spermatozoa.
