Sperm Morphology Assessment in Captive Neotropical Primates.

Area of Science:

• Primate reproductive biology
• Spermatozoa morphology
• Comparative andrology

Background:

• Establishing normative sperm standards is crucial for assessing reproductive health in diverse species.
• Neotropical primates exhibit unique biological characteristics that necessitate species-specific evaluations.
• Previous studies have often relied on subjective methods, limiting comparative accuracy.

Purpose of the Study:

• To evaluate and compare sperm morphology across four neotropical primate species: Callithrix jacchus, Callimico goeldii, Alouatta caraya, and Ateles geoffroyi.
• To establish a basis for normative sperm standards by analyzing morphological traits and morphometric parameters.
• To investigate the utility of subjective and objective sperm analysis methods.

Main Methods:

• Analysis of 80 ejaculates from the four primate species.
• Application of subjective World Health Organization (WHO-2010) standards and Sperm Deformity Index (SDI) criteria.
• Utilization of objective computer-assisted sperm morphometry analysis (CASMA) and subpopulation sperm determination (SSD) methods.

Main Results:

• Significant interspecies differences (p < 0.01) were observed across all evaluated methods (WHO-2010, SDI, CASMA, SSD).
• Multiple significant positive and negative correlations were found between sperm morphological traits and morphometric parameters (p ≤ 0.046).
• Pronounced sperm morphological variation exists among the studied neotropical primate species.

Conclusions:

• The study highlights substantial sperm morphological variation among the four neotropical primate species.
• The strong relationship between morphological and morphometric parameters supports the use of objective analysis.
• Objective methods can enhance the reliability of comparative studies and aid in establishing valid normative sperm values for neotropical primates.