Bradypus variegatus Schinz (1825), popularly known as common sloth, is a wild
mammal of wide distribution, extending from Central America to South America.
However, studies on the reproductive biology of these animals are scarce,
which are necessary to assist in basic and applied research for effective actions
of conservation medicine. In addition, the lack of information on the occurrence
of this species in the state of Tocantins makes it impossible to carry out actions
in wildlife management. Thus, the objective of this work was to survey the
occurrence of the species in the region of Legal Amazon, and to describe and
estimate the population of ovarian follicles of B. variegatus. In order to study the
occurrence of the B. variegatus species, an informational survey was carried
out with the CETAS de Araguaína - TO, a questionnaire survey, and walks in
the microregions of the state of Tocantins and Pará.For the study of morphology
and estimation of ovarian follicles, 4 ovaries were used which were
histologically processed, stained in HE, Masson's Trichrome and PASHematoxinin, and analyzed under a light microscope at 400x. Descriptive and
chi-square statistics were performed at 5% probability. Eight specimens were
observed, 1 in Pará and 7 in Tocantins. Regarding the results of the
questionnaire on the occurrence of the species, 44% of respondents stated that
currently there is difficulty in visualizing the species, consequent to anthropic
actions. On the ovarian morphology, the analysis showed that the ovaries
presented cortex, where ovarian follicles were found in different stages of
development: primordial, primary, secondary and tertiary, dispersed in dense
unformed conjunctive; and the medullary region, internal, formed by loose
vascular connective tissue. In B. variegatus ovaries the follicular population was
estimated in 5,103.3 follicles, being 89% primordial, characterized by granulosa
cells covering the oocyte containing a large nucleus; 7.0% of primary follicles,
which had already had formation of the zona pellucida; 3.0% of secondary
follicles, with several layers of granulosa cells, zona pellucida and developing
inner teak. The tertiary follicles (1.0%) were characterized by the production of
follicular fluid stored in the antrum, in addition to the presence of the teas. No
preovulatory follicles were observed in the ovaries studied. Thus, the records of
B. variegatus in the CETAS - Araguaína, as well as the field observation confirm
the occurrence of the Legal Amazon species. In addition, it was concluded that
common sloth has ovarian morphology similar to that described for other
domestic and wild mammals, presenting for the first time an estimate of
follicular population for this species in Araguaína.
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