Changes in Sperm Morphology, Morphometry, and Motility from the Epididymis to the Vas Deferens in Rheas (<i>Rhea americana</i>, Linnaeus, 1758)
Luana G. P. Bezerra,
Andréia M. Silva,
Artur P. Jurema,
Maiko R. T. Dantas,
Ana G. Pereira,
Moacir F. Oliveira,
Pierre Comizzoli,
Alexandre R. Silva
Affiliations
Luana G. P. Bezerra
Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
Andréia M. Silva
Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
Artur P. Jurema
Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
Maiko R. T. Dantas
Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
Ana G. Pereira
Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
Moacir F. Oliveira
Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
Pierre Comizzoli
Smithsonian National Zoo and Conservation Biology Institute, Washington, DC 20008, USA
Alexandre R. Silva
Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
The objective was to characterize morphological, morphometric, and ultrastructural changes in rhea spermatozoa between the epididymis and the vas deferens. Sperm samples were collected from the reproductive tracts of seven adult individuals and evaluated for sperm characteristics using brightfield microscopy as well as ultrastructural features using scanning electron microscopy (SM). Mean sperm count tended to increase in the vas deferens (378.0 ± 135.0 × 106) compared to the epididymis (201.0 ± 77.4 × 106). Percentages of motile sperm grew from 37.0 ± 4.9% in the epididymis to 58.5 ± 7.7% in the vas deferens. The proportion of normal spermatozoa was 75.6 ± 1.8% and most common defects were bent tails (9.7 ± 0.9%). However, these proportions were not different between epididymis and vas deferens. SM analysis revealed further features of rhea spermatozoa. Normal rhea spermatozoa were threadlike with an acrosome (0.95 ± 0.0 µm), head (7.53 ± 0.01 µm), midpiece (2.08 ± 0.01 µm), and tail (30.7 ± 0.06 µm). Lengths of sperm acrosome, head, midpiece, and tail were longer in the vas deferens compared to the epididymis. Our findings suggest that rhea spermatozoa undergo a maturation process during the passage from the epididymis to the vas deferens.
