CHARACTERISTICS OF THE SEMEN OF 3 ENDANGERED SPECIES OF GAZELLES (GAZELLA-DAMA-MHORR, GAZELLA-DORCAS-NEGLECTA AND GAZELLA-CUVIERI)

As part of a captive breeding programme for three species of endangere d gazelles (Gazella dama mhorr, G, dorcas neglecta and G, cuvieri) the semen parameters for each species were characterized. The volume of e jaculated semen varied widely within species (G, dama: 565-5569 mu l; G dorcas: 0-1454 mu l; G. cuvieri: 50-1411 mu l), as did sperm concent ration (G. dama: 14-1629 x 10(6) ml(-1); G. dorcas: 197-2836 x 10(6) m l(-1); G, cuvieri: 228-927 x 10(6) ml(-1). Sperm motility and viabilit y were high in the three species. G. dama had a significantly lower pr oportion of normal spermatozoa, with a significantly higher proportion having abnormal heads and midpieces and more spermatozoa with cytopla smic droplets. In addition, G. dama tended to have a lower proportion of spermatozoa with normal acrosomes. Sperm heads in G. dama and G, cu vieri were pear-shaped, whereas they were oval in G, dorcas. Spermatoz oa from G. cuvieri were the longest. These data were also analysed in the context of three hypotheses that could explain inter-species diffe rences in semen characteristics. Differences in testes size were due l argely to differences in body size between species. However, no semen characteristic could be explained by allometric relationships. The thr ee gazelle species differed in the intensity of sperm competition las measured by relative testes mass), a factor that could explain differe nces in the proportion of normal spermatozoa. Finally, although the th ree species have reached different levels of inbreeding, this factor d id not explain differences in semen characteristics in the population.