DOI: 10.3897/zoologia.38.e53004

Authors: Tailise M. Dias, Cynthia P.A. Prado, Rogério P. Bastos

Abstract: Anuran males and females adopt different reproductive and behavioral strategies in different contexts. We investigated the reproductive ecology and territorial behavior of the treefrog Boana goiana (B. Lutz, 1968) from the Brazilian Cerrado. We hypothesized that competitor density/proximity would increase the behavioral responses of B. goiana males, and that mating would be assortative. We also tested if the number of eggs correlates with female size and if there is a trade-off between clutch size and egg size. We conducted two territoriality experiments to test the effects of male size, competitor proximity and competitor density. Larger males called more in the presence of a second male. In the second experiment, the largest males emitted more calls and the distance to the nearest male increased as resident males called more. In both experiments, the number of calls was influenced by either male size or spacing between males. Some males behaved as satellites, probably to avoid fights. Our analyses indicate that females choose males with similar sizes to their own, corroborating our hypothesis of size-assortative mating. We found no relationships between female size and clutch size/volume, and between egg size and number of eggs per clutch. We also report multiple spawning for this species. The low incidence of physical combats and the spacing pattern indicate that this species relies almost solely on calls to resolve contests, which could be explained by low motivation, or simply because males avoid combats to decrease injury risks. Thus, acoustic or even multimodal communication seems crucial for social interactions of B. goiana.

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DOI: 10.3897/zoologia.37.e54148

Authors: Antonio Olimpio de Souza, Seixas Rezende Oliveira, Gardênia Proto Dias, Rogério Pereira Bastos, Alessandro Ribeiro de Morais

Abstract: Bioacoustics is an effective way of recording detailed data during population surveys and monitoring. In the present study, we used an automated digital recorder (ADR) to describe the temporal variation in the calling activity of Scinax fuscomarginatus (Lutz, 1925) in central Brazil. We also evaluated the role of climatic variables (air temperature and precipitation) on calling activity by using a Generalized Additive Model (GAM). We conducted the recordings at five ponds in the Cerrado savanna of Rio Verde Municipality, in Goiás state between November 2013 and October 2014. The analysis of the 43.2 hours of acoustic recording showed that S. fuscomarginatus has a prolonged breeding pattern. The ADR provides a fine-scale description of the nocturnal calling pattern, as well as the oscillations between the rainy and dry seasons. The results of the analytical model also indicate that calling patterns were related to minimum (but not maximum) air temperatures and precipitation, which may be related to their reproductive and thermoregulatory requirements. Based on these findings, we conclude that the ADR method has potentially valuable applications for the collection of data on the natural history of anuran species, as well as supplying important insights for conservation initiatives.

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DOI: 10.3897/zoologia.36.e29356

Authors: Pedro Brito, Cíntia P. Targueta, Walquíria Arruda, Fernanda Santos, Rogério Bastos

Abstract: The anuran skin characteristically has different types of glands, most of which are microscopic and are spread throughout the skin. Some species have specialized regions where glands agglomerate, forming macroglands. The description of the external morphology of Ololygon centralis (Pombal & Bastos, 1996) revealed the presence of an inguinal gland. Ololygon centralis is the only species of the genus that has a macrogland. The present study found these inguinal macroglands to be present only on male specimens, thus characterizing it as a sexually dimorphic skin gland. Microscopic analysis revealed that these glands are composed of many syncytial units involved by myoepithelial cells. The center of the syncytium is full of a proteinaceous secretion with a basic pH and the absence of sugar residues. Similar glands observed in other anuran species have been associated with pheromone production, suggesting that the inguinal glands described for O. centralis males may have a similar function.

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DOI: 10.3897/zoologia.34.e20176

Authors: Henrique Alencar Meira da Silva, Thiago Silva-Soares, Lycia de Brito-Gitirana

Abstract: The integuments of ten treefrog species of two genera from Scinaxnae – O. angrensis (Lutz, 1973), O. flavoguttata (Lutz & Lutz, 1939), O. humilis (Lutz & Lutz, 1954), O. perpusilla (Lutz & Lutz, 1939), O. v-signata (Lutz, 1968), Scinax hayii (Barbour, 1909), S. similis (Cochran, 1952), O. trapicheroi (Lutz & Lutz, 1954) and S. x-signatus (Spix, 1824) – were investigated using conventional and histochemical techniques of light microscopy, and polarized light microscopy. All integuments showed the basic structure of the anuran integument. Moreover, the secretory portions of exocrine glands, such as serous merocrine and apocrine glands, were found to be restricted to the spongious dermis. Lipid content occurred together with the heterogeneous secretory material of the glands with an apocrine secretion mechanism. In addition, clusters of these apocrine glands were present in the ventrolateral integument of some species. Melanophores were also visualized in all examined hylids. However, the occurrence of iridophores, detected through polarized light microscopy, varied according to the species. The Eberth-Katschenko layer occurred in the dorsal integument from both genera, but it was only present in the ventral integument of O. albicans, O. angrensis, O. flavoguttata, O. perpusilla and O. v-signata. Although the integument of all treefrogs showed the same basic structure, some characteristics were genus-specific; however, these features alone may not be used to distinguish both genera.

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DOI: 10.3897/zoologia.34.e20477

Authors: Laura Gomez-Mesa, Juliane Pereira-Ribeiro, Átilla Colombo Ferreguetti, Marlon Almeida-Santos, Helena G. Bergallo, Carlos Frederico D. Rocha

Abstract: Presented is the first information on the ecological and reproductive aspects of the treefrog, Aparasphenodon brunoi Miranda-Ribeiro, 1920, living in ombrophilous forest areas of the Atlantic Rainforest, Brazil. We recorded the species’ daily activity and over the course of a year, population density during the year, microhabitat usage, diet, and some reproductive features (quantity, diameter and mean mass of oocytes, mean reproductive effort of female). Field sampling was conducted monthly from June 2015 to July 2016. Searches for treefrogs were systematic, using visual encounter surveys along 14 plots RAPELD long term research modules established in the forest. For each captured individual, we recorded the hour, microhabitat used, and perch height. The diet of the population was ascertained based on 15 individuals collected outside the study plot areas. Treefrogs used seven different types of microhabitats in the forest but the preferred microhabitats were tree-trunks and lianas. The amount of accumulated rainfall and air temperature interacted to explain the number of A. brunoi individuals active throughout the year. The reproductive strategy for females of this comparatively large arboreal frog in the ombrophilous forest is to produce clutches with a large number (900.8 ± 358.1) of relatively small-sized eggs. We conclude that in the ombrophious forest of the Vale Natural Reserve, A. brunoi is a nocturnal arboreal treefrog active throughout the year but activity increases during the wet season as a result of increased precipitation. In the forest, treefrogs tend to perch mainly on tree-trunks and lianas about 1 m above ground, where it feeds preferably on relatively large bodied arthropod prey. When living in the ombrophilous forest of the Atlantic rainforest, A. brunoi may change some features of its ecology (e.g. marked difference in the use of bromeliads) compared to when living in restinga habitats.

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