Sperm Morphology Assessment in Captive Neotropical Primates

The main objective of this study was to evaluate sperm morphology in four neotropical primate species to compare the sperm morphological traits and the sperm morphometric parameters as a basis for establishing normative sperm standards for each species. Data from 80 ejaculates collected from four primate species, Callithrix jacchus, Callimico goeldii, Alouatta caraya and Ateles geoffroyi, were analysed for detection of sperm morphological alterations using subjective World Health Organization (WHO-2010) standards and Sperm Deformity Index (SDI) criteria, objective computer-assisted sperm morphometry analysis (CASMA) and subpopulation sperm determination (SSD) methods. There were multiple differences (p < 0.01) observed among primate species in values obtained from WHO-2010, SDI, CASMA and SSD sperm analysis methods. In addition, multiple significant positive and negative correlations were observed between the sperm morphological traits (SDI, Sperm Deformity Index Head Defects, Sperm Deformity Index Midpiece Defects, Sperm Deformity Index Tail Defects, Normal Sperm, Head Defects, Midpiece Defects and Tail Defects) and the sperm morphometric parameters (SSD, Area (A), Perimeter (P), Length (L), Width (W), Ellipticity, Elongation and Rugosity) (p ≤ 0.046). In conclusion, our findings using different evaluation methods indicate that pronounced sperm morphological variation exists among these four neotropical primate species. Because of the strong relationship observed among morphological and morphometric parameters, these results suggest that application of objective analysis methods could substantially improve the reliability of comparative studies and help to establish valid normative sperm values for neotropical primates.