Establishing the hypoosmotic swelling test for sperm analysis in collared peccaries (Pecari tajacu) / Estabelecimento do teste hiposmótico para a análise de sêmen de catetos (Pecari tajacu)

Soluções hiposmóticas com diferentes concentrações (0, 50, 100, 150, 200mOsm/L) foram testadas para a avaliação funcional da membrana espermática de catetos (n=13). Foi verificado que o número de espermatozoides reagidos diminuía (P<0,05) de acordo com o aumento da osmolaridade do meio. A maior porcentagem (71,8%) de espermatozoides reagidos, bem como a menor variação nas respostas osmóticas, foi detectada com o uso de água destilada (0mOsm/L) (P<0,05), a qual também apresentou a menor variação nos resultados, de acordo com os erros padrão verificados. Em conclusão, a água destilada aparenta ser uma solução adequada para o uso no teste hiposmótico para sêmen de catetos.

Assessment of sperm survival and functional membrane integrity of the six-banded armadillo (Euphractus sexcinctus).

The objective was to evaluate sperm survival in the six-banded armadillo, using a thermoresistance test, and to compare sugar solutions with varying osmolarities to analyze the integrity of the functional sperm plasma membrane in this species. Twelve ejaculates were obtained from four mature males by electroejaculation and evaluated for sperm motility, vigor, live sperm, and morphology. Sperm survival was evaluated during a thermoresistance test at 34 °C (the body temperature of this species). The functional integrity of the plasma membrane was evaluated by means of the hypo-osmotic swelling test (HOST), using solutions of varying osmolarities (0, 50, 100, and 150 mOsm/L). During the thermoresistance test, at each evaluation, there was a reduction (P < 0.05) in mean values for sperm motility, sperm vigor, and percentage of live sperm (no movement was observed at 360 min). Sperm survival varied among individual armadillos (P < 0.05). In two individuals, sperm vigor was significantly enhanced when semen was diluted in Tris extender. The response of armadillo sperm to the HOST varied among individuals (P < 0.05). On average, maximal values (P < 0.05) of reactive sperm (59%) were detected with 50 mOsm/L solution; furthermore, this concentration had the largest significant positive correlation (r = 0.84) to live sperm percentage. In conclusion, six-banded armadillos had significant individual variation with regard to sperm survival in a thermoresistance test at 34 °C; in some individuals, sperm survived until 360 min. The use of a 50 mOsm/L fructose solution was recommended for conducting a HOST in this species.