Hélio Ricardo da Silva

Lagartos da Marambaia, um remanescente insular de Restinga e Floresta Atlântica no Estado do Rio de Janeiro, Brasil

Carvalho, A.L.G., Araujo, A.F.B. and Silva, H.R. Lizards of Marambaia, an insular remnant of Restinga and Atlantic Forest in the State of Rio de Janeiro, Brazil. Biota Neotrop. May/Aug 2007 vol. 7, no. 2. http:// www.biotaneotropica.org.br/v7n2/pt/abstract?inventory+bn03407022007. ISSN 1676-0603. This work presents the results of a survey of the lizard species that occur in Marambaia, RJ. Twelve species of lizards, distributed in seven families were registered. Teiidae is the richest family (3 spp.), followed by Gekkonidae (2), Scincidae (2), Tropiduridae (2), Gymnophthalmidae (1), Leiosauridae (1), and Polychrotidae (1). The lizard fauna of Marambaia is similar to that occurring in other localities in the southeastern coast of Brazil. Nevertheless, Marambaia harbors Cnemidophorus littoralis and Liolaemus lutzae, species restricted to restinga habitats in Rio de Janeiro State and considered under threat. The area also protects typical forest species, including the arboreal lizards Enyalius brasiliensis and Anolis cf. fuscoauratus. Forest and restinga are continuous in Marambaia and represent the richest habitats for lizards, comprising nine and eight species, respectively. The possibility of genetic variability loss due to the geographical isolation of the area, and the apparent difficulty of re-colonization in the case of local loss of diversity, added to environmental modifications caused by human activities, are worrying issues for the conservation of Marambaia herpetofauna.

Records of the rattlesnakes Crotalus durissus terrificus (Laurenti) (Serpentes, Viperidae) in the State of Rio de Janeiro, Brazil: a possible case of invasion facilitated by deforestation

This paper documents the presence of rattlesnakes, as an invasive species, in several municipalities of the State of Rio de Janeiro. As previous registers indicate, these snakes probably invaded at least the municipality of Valenca carried by floodwaters between the decades of 1950 and 1960. In the new environment, along the margins of the Rio Preto, these snakes were able to establish new populations in deforested areas turned into cattle grazing. The presence of rattlesnake in the municipality of Barra do Pirai, a municipality that has no border with Rio Preto, however, indicates that these snakes dispersal into new areas may be facilitated by open areas, represented by pastures, created after deforestations.

Frogs of Marambaia: a naturally isolated Restinga and Atlantic Forest remnant of southeastern Brazil

We report the results of a seven-year survey of the anurans of Marambaia, in the State of Rio de Janeiro, southeastern Brazil, where 24 species were recorded. The species represented nine families: Hylidae (10 species), Bufonidae (3), Leptodactylidae (3), Hylodidae (2), Microhylidae (2), Craugastoridae (1), Centrolenidae (1), Cycloramphidae (1), and Leiuperidae (1). We also present notes on the natural history and habitat usage by the anurans.

Life in bromeliads: reproductive behaviour and the monophyly of the Scinax perpusillus species group (Anura: Hylidae)

Several aspects of the reproductive behaviour of species of the Scinax perpusillus group (S. perpusillus, S. v‐signatus, S. littoreus, and three other not yet described species) obtained from direct field observations and nocturnal video filming are presented and evaluated. Males of the observed species have behavioural characters, including aspects of their call, that are indicative of territory defence. Vocalizations are elaborate and represent intra‐ and inter‐sexual communication mechanisms. Females present behaviour relating to the inspection of egg‐laying sites (bromeliad leaf‐tanks), reduced and partitioned clutch. This set of behaviours is not only indicative of a sophisticated control mechanism over egg laying and spermatozoid release, but also of the existence of a behavioural repertoire that probably originated in the ancestor of these species and could be considered a synapomorphy for this group of species. Furthermore, the behaviours described herein comprise a new reproductive strategy for frogs that reproduce in bromeliads.

Feeding ecology of Tropidurus torquatus (Wied) (Squamata, Tropiduridae) in two areas with different degrees of conservation in Marambaia Island, Rio de Janeiro, Southeastern Brazil

We compared the effects of habitat disturbance on the feeding ecology of two local populations of Tropidurus torquatus (Wied, 1820) in restinga habitats on Ilha da Marambaia, Southeastern Brazil. Both populations presented a relatively diverse diet and differ in the number (DMax = 0.22, DF = 2, p = 0.00) and volume of prey consumed (DMax = 0.82, DF = 2, p = 0.00). Ants were the most frequent and numerous preys in both areas, and plant matter and coleopterans were the most important alimentary items in volume. The population from the disturbed area presented a larger niche breadth for number of prey items consumed (Binum = 3.06) and volume (Bivol = 2.98), when compared to the other population (Bjnum = 2.44, Bjvol = 1.52). Niche overlap was higher for number of items consumed between the populations (Oijnum = 0.82) but lower for volume (Oijvol = 0.05). Our data suggest dietary differences between the two lizard populations, and these differences may be associated with environmental modifications. Our main hypothesis to explain the dietary differences is based in the Optimal Foraging Theory. However, the alimentary behavior, and consequently the diet of these lizards, seems to be constrained phylogenetically, with a pattern that may have evolved in the ancestor of all iguanids.

Leptodactylus ocellatus (Amphibia): mechanism of defense in the skin and molecular phylogenetic relationships.

Amphibian antimicrobial peptides have been known for many decades and several of them have already been isolated. However, the number of species investigated is still small. Herein, we report on the skin secretions of Leptodactylus ocellatus, which were extracted by mild electrical stimulation and its semi-preparative reverse-phase chromatography was resolved in more than 30 fractions. Among these fractions, two novel antimicrobial peptides were isolated and their amino acid sequences determined by de novo sequencing. The ocellatins-5 and -6 (21 and 22 amino acid residues, respectively) are amidated at the C-terminus. Ocellatins inhibited the growth of reference strains of both Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) with minimal inhibition concentration values in the range of 32-128 microg/mL. The amino acid sequence of the peptides shows structural similarity with members of the antimicrobial peptides found in the skin secretion of other leptodactylid frogs. This observation is consistent with the hypothesis that many frog skin antimicrobial peptides are related evolutionarily, having arisen from multiple duplications of an ancestral gene that existed before the radiation of the different species.

A new species of Phyllodytes (Anura, Hylidae) from southern Bahia, Brazil

T HE genus Phyllodytes is composed of small species of treefrogs having odontoids on the mandible, a unique character among hylids. The species occur in eastern Brazil and Trinidad, in regions of open vegetation, where they call from, and breed in, bromeliads. Tadpoles develop in accumulated rain water in these plants. During a field trip to a region in southern Bahia, Brazil, we explored an area with a high density of bromeliads and collected a distinctive species of the genus Phyllodytes. In this paper, we describe this new species and present a description of the tadpole and notes on its habits and habitat. The abbreviations used in the account below

Uma nova espécie de Hylodes Fitzinger da Serra da Mantiqueira, Minas Gerais, Brasil (Anura: Hylodidae)

We describe a new species of Hylodes Fitzinger, 1826 from Serra Negra, Municipality of Santa Barbara do Monte Verde, State of Minas Gerais, southeastern Brazil. The new species is a member of the Hylodes lateristrigatus group, characterized by the following combination of traits: small size, snout truncated in dorsal and in lateral views, upper surface of finger discs without well developed scutes, dorsum and dorsal portion of thigh light olive-brown with dark blotches, and dark stripes in the thighs. The new species is distinguishable from the other species of the group by details of the advertisement call, and because its the first species registered for the genus that besides calling during the day, also calls at night. This is the first record of nocturnal call for the genus. Descriptions of vocalizations and information on natural history are provided. We also present a discussion on a possible patter of distribution of the genus relating to the highlands and todays drainage systems.

Patterns of parasitism by Eutrombicula alfreddugesi (Oudemans) (Acari, Trombiculidae) in three species of Tropidurus Wied (Squamata, Tropiduridae) from Cerrado habitat of Central Brazil

This study concerns the patterns of parasitism by the larvae of Eutrombicula alfreddugesi (Oudemans, 1910) on three species of Tropidurus Wied, 1820 from Cerrado habitats of Central Brazil: T. oreadicus Rodrigues, 1987 (n = 97), T. itambere (n = 85) and T. torquatus (Wied, 1820) (two samples n = 75, n = 23). The highest prevalence value was observed in T. itambere (88.2%), followed by T. oreadicus (87.6%), and T. torquatus (17.3% and 65.2%). The most important sites of infestation were the mite pockets and skin folds, especially on the neck and inguinal region. Tropidurus itambere Rodrigues, 1987 was the most heavily parasitized species (mean intensity of infestation: 36.67 ± 41.09), followed by T. oreadicus (15.38 ± 21.08), and T. torquatus from Unai, Minas Gerais (12.13 ± 21.09). The lowest intensity of infestation was found in T. torquatus from urban and periurban areas of Brasilia, Distrito Federal (1.97 ± 5.43). The analysis did not indicate differences in intensity of infestation between sexes for any of the species. Differences in the patterns of parasitism among the three lizard species may be related to the morphological and numerical variation of the skin folds (especially mite pockets), to the degree of conservation of the hosts habitats, and to selective processes related to reduction of damage to the hosts bodies, to the evolution of mechanisms of decreasing illness transmission by parasites, or even to some behavioral traits of the lizards.

Phylogenetic systematics of egg-brooding frogs (Anura: Hemiphractidae) and the evolution of direct development

Egg-brooding frogs (Hemiphractidae) are a group of 105 currently recognized Neotropical species, with a remarkable diversity of developmental modes, from direct development to free-living and exotrophic tadpoles. Females carry their eggs on the back and embryos have unique bell-shaped gills. We inferred the evolutionary relationships of these frogs and used the resulting phylogeny to review their taxonomy and test hypotheses on the evolution of developmental modes and bell-shaped gills. Our inferences relied on a total evidence parsimony analysis of DNA sequences of up to 20 mitochondrial and nuclear genes (analyzed under tree-alignment), and 51 phenotypic characters sampled for 83% of currently valid hemiphractid species. Our analyses rendered a well-resolved phylogeny, with both Hemiphractidae (sister of Athesphatanura) and its six recognized genera being monophyletic. We also inferred novel intergeneric relationships [((Cryptobatrachus, Flectonotus), (Stefania, (Fritziana, (Hemiphractus, Gastrotheca))))], the non-monophyly of all species groups previously proposed within Gastrotheca and Stefania, and the existence of several putative new species within Fritziana and Hemiphractus. Contrary to previous hypotheses, our results support the most recent common ancestor of hemiphractids as a direct-developer. Free-living aquatic tadpoles apparently evolved from direct-developing ancestors three to eight times. Embryos of the sister taxa Cryptobatrachus and Flectonotus share a pair of single gills derived from branchial arch I, while embryos of the clade including the other four genera have two pairs of gills derived from branchial arches I and II respectively. Furthermore, in Gastrotheca the fusion of the two pairs of gills is a putative synapomorphy. We propose a revised taxonomy concordant with our optimal topologies.