Biologia reprodutiva de Pithecopus gonzagai (Anura, Phyllomedusidae) no Nordeste do Brasil

Abstract

Reproduction is a component of species biology that shapes the morphology of individuals, influences predation and defense behavior, acts on the choice of living habitats, and acts on the physiology of species. Therefore, the objective of this study is to describe the reproductive pattern of the species Pithecopus gonzagai, to characterize the histological aspects of the gonads, the body growth rates, and their relationships with seasonal variations. This study was carried out at the Tapacurá Ecological Station (EET) - PE and at the Olho D'água da Bica Forest Garden (HFODB) - PB. Monthly nocturnal expeditions were conducted between the period of February 2018 to January 2019 at EET and between the months of August 2020 to July 2021 at HFODB. Captured animals were euthanized by overdosing 5% anesthetic, had their Cloacal Rostrum Length measured using a digital caliper and weighed with precision scales. The gonads, livers, and fat bodies were removed, measured at their greatest rectilinear length with a digital pachymeter, and weighed with an analytical scale. The body masses of the gonads, livers and fat bodies were used to calculate the body condition factor, gonadosomatic index, hepatosomatic index and liposomatic index, respectively. The gonads were subjected by a classical histological protocol and embedded in paraffin. Sectioned at 5.0 μm and stained in H/E. Qualitative analysis was obtained using a conventional microscope coupled to a digital imaging system. The density and volume of the final cells of spermatogenesis were calculated: spermatids I, spermatids II and spermatozoa. To quantify the density of profiles, fields were counted in a test area with 0.044 mm² for each animal. The final result (mm²) was acquired after using the average for each profile and applying the formula: QA = Ʃperfis/AT. The monthly rainfall data were acquired through the database of the Waters and Climate Agency of Pernambuco and the Executive Agency Center for Water Management of the State of Paraíba. As for the data on temperature and relative humidity, they were acquired using a Thermo-Hygrometer in the areas where the animals were collected in each monthly expedition. A total of 42 individuals of P. gonzagai were collected in the TSE and 64 in the HFODB. Through the results obtained for the values of K1, IGS, IHS and ILS over the months sampled, for both populations, there was no significant relationship with precipitation in their respective study areas. Germ cells showed significant relationship for females in HFODB. The processes of gonadal growth and weight, weight of livers and fat bodies, as well as spermatogenesis and gametogenesis. They showed a positive relationship with precipitation in their respective study areas. Although there was no statistically significant relationship. We conclude that the reproductive activity of the species Pithecopus gonzagai is classified as potentially continuous.