CONICET | Buscador de Institutos y Recursos Humanos

The characterization of sperm morphology and morphometry has been used as taxonomic and phylogenetic tool in different species of mammals due to its high diversity. Considering that these studies are very scarce in Primates, we contributed with a preliminary analysis of the sperm morphometry from one male of 5 Neotropical Primate species: Atelidae: Alouatta caraya (ACA), Ateles belzebuth (ABE), A. chamek (ACHA); Cebidae: Cebus libidinosus (CLI), C. nigritus (CNI). The spreads were performed from semen samples taken following a standardized protocol of electroejaculation. In some species a seminal coagulum was present (ABE, ACHA, CLI and CNI), therefore it was disaggregated by enzymatic (collagenase and trypsin) and mechanical treatment. Howel & Black and Buffered Giemsa staining were applied. The proportions measured in 100 spermatozoa of each species were: total length, head length, head width, acrosome length, midpiece length, midpiece width and tail length. The sperm head of Cebidae spermatozoa was wider and larger than the one of Atelidae spermatozoa. The mean head length and mean midpiece length was larger in the cebids than in the atelids (Mean±SD: 6.118 ±0.061 and 9.299±1.196 vs. 5.230±0.131 and 5.927±1.999, respectively). Among Cebidae, CNI presented a longer midpiece and a shorter acrosome length than CLI (10.145±0.054 and 3.364±0.097 vs 8.453±0.651 and 3.895±0.177, respectively). Among Atelidae, Ateles sp. spermatozoa showed a larger midpiece length than Alouatta sp. (7.064±0.388 vs 3.651±0.052). ABE spermatozoa were the longest (70.468±3.201), whereas ACA were the shortest (50.701±1.117). The data was compared with previous reports of non-human primates and discussed in a phylogenetic and reproductive framework.