Abstract

SANCHEZ-LORIA, O.L. et al. Influence of sexual interactions on vitellogenesis in Salvator merianae females in captivity. Rev. agron. noroeste arg. [online]. 2021, vol.41, n.2, pp.107-114.  Epub Sep 26, 2023. ISSN 0080-2069.

In oviparous reptiles, follicular growth and vitellogenesis are influenced by environmental, social, and hormonal factors. The aim of this study was to test the effect of male presence, mating or other signals, on the follicular development and behavior of Salvator merianae females. The study was carried out with S. merianae females from the Experimental Hatchery of Facultad de Agronomía y Zootecnia (Universidad Nacional de Tucumán). Social and reproductive behaviors were observed in females in the presence of males (in hatchery, reproductive families or sexual isolation), and in the absence of males (in groups or individually). Proportion of vitellogenic cycles, development and growth rate of ovarian follicles and copula-follicular size relationship were determined. The females in reproductive families behaved normally, without attempts to escape or aggressions among them, with a significantly higher percentage of vitellogenic cycles (80 %) and with a follicular growth rate higher than that of the 3 groups in sexual isolation. The 87.5 % of the females receptive to the male, copulated with sonographically vitellogenic follicles. The 64 % of the females isolated sexually close to males, performed vitellogenic cycles. In the group of females without males, females isolated individually showed a certain degree of aggressiveness and 47 % showed vitellogenesis; while females in isolated groups were aggressive and attempted to escape, with 31 % of them undergoing vitellogenesis. The results indicated that, although the male acts as an “enhancer” of vitellogenesis, the initiation of this process is independent of its presence. Regarding behavior, deprivation of individuals of the opposite sex seems to increase aggressiveness and decrease ovarian development, particularly in group-isolated females.

Keywords : Argentine black-and-white tegu; Sexual isolation; Ovarian follicles; Ultrasonography; Animal sexual behavior.

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