Sperm analysis

There is genetic evidence that the two species of Brazilian grey Mazama, Mazama gouazoubira and Mazama nemorivaga, belong to different genera. This study identified significant differences that separated them into distinct groups, by analysing characteristics of the spermatozoa and ejaculate of both species. The characteristics that most clearly differentiated between the species were ejaculate colour, white for M. gouazoubira and reddish for M. nemorivaga, and sperm head dimensions; the area and width were the main variables that distinguished these species. Multivariate analysis of sperm size and sperm head format data accurately discriminated the two species (discrimination between two groups) with low error identification (0.0021), while the individuals analysed (discrimination between 5 groups) formed three groups (error identification = 0.16): group 1, individuals of M. nemorivaga; group 2, individuals of M. gouazoubira; and group 3, a single individual of M. gouazoubira. The results obtained in this work corroborate the hypothesis of the formation of new genera, and subspecies, for species of grey Mazama. Moreover, the low-cost and easily applied method described herein can be used as an auxiliary tool to identify subspecies or sibling species of other taxonomic groups.