Abstract

MONTES-PETRO, César et al. Testicular Maturity and Seminal Quality of Ichthyoelephas longirostris (Prochilodontidae) from the Middle Cauca River. Acta biol.Colomb. [online]. 2024, vol.29, n.3, pp.179-188.  Epub Sep 03, 2024. ISSN 0120-548X.  https://doi.org/10.15446/abc.v29n3.112600.

Ichthyoelephas longirostris is an endemic species of Colombia distributed in the Magdalena-Cauca and Rancheria basins that have been declared in danger of extinction. Knowledge of its bio-ecology, particularly its reproductive aspects, is limited. Therefore, the study aimed to determine the testicular maturity stage and seminal quality of I. longirostris from the Cauca River Middle. The testicular development was established through the morphological and histological description of males (n = 28, 0.78±0.14 Kg, 42.1±2.5 cm) captured monthly between August/2020 and October/2021 in the Cauca River Middle (Valdivia, Colombia). Furthermore, semen quality was evaluated in males kept in captivity (n = 8, 0.7 ± 0.1 Kg, 40.3 ± 1.3 cm) that matured, were induced with 4 mg carp pituitary extract/Kg weight, and six hours post-induction, the semen was collected and with a computer-assisted analysis system (CASA) the kinetics, concentration, and duration of sperm motility were evaluated. The I. longirostris testes are elongated paired saccular-shaped structures of unrestricted lobular type with cystic development that present four basic stages: immature, maturing, mature, and post-release/regression. Mean values of concentration (10546.4 ± 3344.0 spz/mL), total motility (95.2 ± 3.8 %), total progressivity (72.7 ± 15.3 %), curvilinear velocity (117.6 ± 21.8 µm/s), linear velocity (70.1 ± 14.3 µm/s) and duration of motility (39.5 ± 2.5 s) were estimated. The development of testicular maturity and seminal quality of I. longirostris is like those reported for other neotropical prochilodontids.

Keywords : gonads; motility; spermatocytes; spermatogonia; spermatozoa.

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