Marlon Almeida-Santos

Anurofauna of an Atlantic Rainforest fragment and its surroundings in Northern Rio de Janeiro State, Brazil

We carried out a study on the anurofaunal community from an Atlantic Forest fragment (Monte Verde mountains) and the surrounding area in Cambuci municipality, Rio de Janeiro State, Brazil, which constitutes one of the largest fragments remaining in the largely deforested landscape of the northern portion of the State. We combined three sampling methods: plot sampling, transects and pit-fall traps. We recorded twenty species of amphibians, of which only eleven were found within the forest fragment (and five of these also occurred in the surrounding matrix). Two of the species recorded in the present study (Crossodactylus sp. and Ischnocnema cf. parva) may represent undescribed taxa. Our records expand the distribution range of one species (Scinax trapicheiroi) to the north, and fill a geographic distribution gap for another one (Ischnocnema oea). The estimated overall density of frogs living in the leaf litter of the fragment (based on results of plot sampling) was 3.1 individuals/100 m², with Haddadus binotatus being the most abundant species (2.4 individuals/100 m²). Comparisons of our data with those of other studies suggest that anuran communities in forest fragments ca. 1,000 ha or smaller may be severely limited in their richness, and often include a large proportion of species tolerant to open areas, such as many hylids. Our results show the importance of increasing knowledge about the anurofaunal community of the northern portion of the State of Rio de Janeiro and preserve the forest remnants that still exist in the region.

Density and richness of leaf litter frogs (Amphibia: Anura) of an Atlantic Rainforest area in the Serra dos Órgãos, Rio de Janeiro State, Brazil

Data on species composition, richness, and density are presented for the leaf litter frog assemblage of an area of Atlantic Rainforest at the Serra dos Orgaos mountain range, in the state of Rio de Janeiro, southeastern Brazil. Three sampling methods were used: plot sampling, visual encounter surveys, and pitfall traps. The local assemblage of leaf litter frogs was composed of 16 species, with the direct-developing species, Euparkerella brasiliensis (Parker, 1926), being the most abundant. The estimated density of the local leaf litter frog assemblage based on plot sampling was 17.1 ind/100 m2 and the estimated overall leaf litter frog mass was 684.2 g/ha. The estimated density of leaf litter frogs at the present study is the highest currently reported for Atlantic Rainforest areas, which reinforces the idea of higher densities of leaf litter frogs in the Neotropical Region compared to the Old World tropics.

Ecology of the Brazilian Flea Frog Brachycephalus didactylus (Terrarana: Brachycephalidae)

Abstract Brachycephalus didactylus, a leaf litter frog endemic to the Brazilian Atlantic rain forest, is considered the worlds smallest tetrapod. Currently, there is little information about the ecology of this species. In this study, we estimated the population density and analyzed the diet, sexual dimorphism, and some reproductive aspects of two populations of B. didactylus in Rio de Janeiro State, Brazil. The estimated density was 4.0 and 1.2 ind/100m2, suggesting that this is not a locally rare species. However, collecting these frogs may be difficult because of their very small body size (< 11.0 mm SVL) and cryptic color pattern. Individuals from the two populations did not differ in body size, but females from one population were significantly larger than were males. In both populations, the most important food items consumed were Acari and Collembola, most of them measuring less than 1.0 mm in length. Females of the two populations had 3.6 ± 1.3 and 2.5 ± 0.8 mature oocytes averaging 1.6 ± 0.5 mm and 1.4 ± 0.5 mm in diameter, respectively. Frogs with direct-development generally deposit a relatively small number of eggs, and this trend is even more extreme in miniaturized species, such as B. didactylus, which probably lays one egg per clutch. Because the body size of females significantly influenced the mean diameter of oocytes, but not the number of oocytes per female, reproductive success is probably associated with the production of relatively large eggs and, consequently, larger froglets, which may confer an adaptive advantage.

Ecological aspects of the pumpkin toadlet, Brachycephalus garbeanus Miranda-Ribeiro, 1920 (Anura: Neobatrachia: Brachycephalidae), in a highland forest of southeastern Brazil

Brachycephalus garbeanus is an aposematic toadlet, endemic to the Atlantic Forest in the mountains of the state of Rio de Janeiro, southeastern Brazil. Information regarding the ecology of species in this genus is scarce, with no information on most species, including B. garbeanus. We provide ecological information about B. garbeanus, in particular regarding microhabitat use, sexual dimorphism in body size, and feeding habits. Our study was conducted in a montane area of the Parque Estadual dos Três Picos, the largest State park in Rio de Janeiro. Most of the B. garbeanus in the study area were found on the forest floor leaf litter. Females were larger on average than males. Brachycephalus garbeanus consumed a wide array of prey, comprising exclusively invertebrates and predominantly arthropods. There were seasonal differences in the diet composition, but mites and ants were important in both wet and dry seasons.

New host records for Amblyomma rotundatum (Acari: Ixodidae) from Grussaí restinga, Rio de Janeiro, Brazil

Amblyomma rotundatum Koch is a parthenogenetic tick usually associated with reptiles and amphibians. However, relatively few studies on occurrences of ticks in wild reptile populations in Brazil have been produced. The aim of this study was to analyze the presence of ticks associated with reptile species in the Grussaí restinga, in the municipality of São João da Barra, state of Rio de Janeiro, Brazil. Between December 2010 and January 2011, 131 individuals belonging to nine species of reptiles of the order Squamata were sampled: the lizards Tropidurus torquatus (n = 51), Hemidactylus mabouia (n = 25), Mabuya agilis (n = 30), Mabuya macrorhyncha (n = 6), Cnemidophorus littoralis (n = 5) and Ameiva ameiva (n = 10); and the snakes Philodryas olfersii (n = 2), Oxyrhopus rhombifer (n = 1) and Micrurus corallinus (n = 1). The only tick species found to be associated with any of the reptiles sampled was A. rotundatum. One adult female was detected on one individual of the lizard A. ameiva, one nymph on one individual of the lizard T. torquatus and four nymphs on one individual of the snake P. olfersii. This study is the first record of parasitism of A. rotundatum involving the reptiles T. torquatus and P. olfersii as hosts. Our results suggest that in the Grussaí restinga habitat, A. rotundatum may use different species of reptiles to complete its life cycle.