Crizanto Brito De-Carvalho

Bio: Crizanto Brito De-Carvalho is an academic researcher from Universidade Federal de Sergipe. The author has contributed to research in topics: Type locality & Ecological niche. The author has an hindex of 6, co-authored 15 publications receiving 110 citations.

Diet of Rhinella schneideri (Werner, 1894) (Anura: Bufonidae) in the Cerrado, Central Brazil.

Abstract: This study describes the diet of Rhinella schneideri based on the analysis of the stomach contents of 18 specimens from an area within the Cerrado, Central Brazil. We found 842 items belonging to 11 prey categories, including the plant material category. The most important prey categories for R. schneideri were Insect larvae, Coleopteran and Formicidae. Numerical and volumetric niche breadths of R. schneideri were 3.35 and 1.00, respectively. According to its diverse diet and abundance, R. schneideri may be considered a generalist and opportunist species.

História natural de Leptodactylus mystacinus e Leptodactylus fuscus (Anura: Leptodactylidae) no Cerrado do Brasil Central

Abstract: Aspects of the ecology of Leptodactylus mystacinus and Leptodactylus fuscus were investigated in an area of the Cerrado of Central Brazil The study included use of microhabitat, activity patterns, diet and, morphometry Observations were conducted between April, 2006, and February, 2007 The species are sexually dimorphic - females larger than males - and body size in L mystacinus is larger than that of L fuscus Both species preferred the ground surface (microhabitat) of wetland habitats with herbaceous vegetation close to lentic water bodies Leptodactylus mystacinus was observed most often in October and November (8:00-8:59 PM and 11:00-11:59 PM), and L fuscus in November and October between 7:00 PM and 8:59 PM The diet of both populations was based on Arthropoda, primarily Coleoptera, which was the most important order (IVI) Differences in the volumetric proportions of the categories of then preys used, and in the periods when they were most observed, are probably the factors that contribute the most to the coexistence of both species in the area Intersexual differences in the diet were observed in both species These differences were probably associated with the differential allocation of resources to the production of gametes or occasional differences in the use of space by the two sexes

Nicho ecológico e aspectos da história natural de Phyllomedusa azurea (Anura: Hylidae, Phyllomedusinae) no Cerrado do Brasil Central

Abstract: Aspects of the ecology and natural history of Phyllomedusa azurea were investigated in an area of Central Brazilian Cerrado between April, 2006, and February, 2007. Observations were conducted between 6:00 PM and 5:00 AM. The study focused on spatial, temporal, and trophic niches, morphometry and reproduction. Most animals were recorded vocalizing in places dominated by herbaceous vegetation and an open canopy. The main substrates used were bushes and trees, and animals were seen perched most often between 0.5 and 1.0 m of height. Spatial niche breadth was 2.91 and 3.83 for substrate and perch height, respectively. Most animal were sighted close to lentic water bodies, usually up to 0.50 m. It is possible that these characteristics are related primarily to the phylogeny of the genus and secondarily to the specific needs of the species and the local availability of resources. The bushes and trees were used by the species mainly as sites of vocalization and oviposition. Specimens of Phyllomedusa azurea was sighted most frequently between 8:00 PM and 9:00 PM. Estimated temporal niche breadth (activity period) was 4.68. Prolonged reproductive pattern was also observed predominantly in the months with higher temperature and higher humidity (September to February). The diet consisted of eleven items. The most important prey taxon for the females was Orthoptera (IVI = 63), whereas for the males, it was Araneae (IVI = 33). The breadths numeric and volumetric of the trophic niche, was respectively 1.80 and 1.16, for females, and 4.03 and 3.92, for males. Males and females differed in size (SVL) and mass, with the females being larger and heavier. The sizes of smaller reproductive individuals males and females were 34.64 and 40.33 mm, respectively. Differences in size may be related to different investments in reproduction by the two sexes.

Abundance of Callicebus barbarabrownae (Hershkovitz 1990),(Primates: Pitheciidae) and other nonvolant mammals in a fragment of arboreal Caatinga in northeastern Brazil

Abstract: Abstract The semi-arid Caatinga of the Brazilian northeast is a fragile, poorly known scrubland biome, which suffers increasing anthropogenic impacts. While 143 mammal species are known from the biome, few data are available on community composition or population parameters. In the present study, a 115-ha fragment of arboreal caatinga was surveyed in northern Sergipe in 2009 using standard line transect procedures. Total transect length was 133 km, and density estimates were calculated using sighting functions. Additional information on the occurrence of mammalian species was collected non-systematically. Nine species, including three carnivores, were confirmed in the study area, but only three were recorded in the surveys, two of which [the critically endangered blond titi, Callicebus barbarabrownae (Hershkovitz 1990), and the rock cavy, Kerodon rupestris (Wied-Neuwied 1820)] are endemic to the Caatinga. The third species was the common marmoset, Callithrix jacchus (Linnaeus 1758). C. jacchus and K. rupestris were relatively abundant, with estimated densities of 169.7 and 116.7 individuals per km2, respectively, but C. barbarabrownae was rare, and the local population was estimated to contain only five individuals, i.e., approximately four individuals per km2. If typical, densities this low would probably threaten the viability of C. barbarabrownae populations at most, if not all sites in which the species still occurs.

First record of Siphonops paulensis Boettger, 1892 (Gymnophiona: Siphonopidae) in the state of Sergipe, northeastern Brazil

Abstract: Siphonopidae is represented by 25 caecilians species in South America. In Brazil, Siphonops paulensis is found in the states of Maranhao, Rio Grande do Norte, Bahia, Tocantins, Goias, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Sao Paulo, Rio de Janeiro, Rio Grande do Sul, and in the Distrito Federal. Herein, we report the first record of Siphonops paulensis in the state of Sergipe, Brazil, Simao Dias municipality. This record significantly expands the distribution of the species in northeastern Brazil.

Big, Bad, and Beautiful: Phylogenetic Relationships of the Horned Frogs (Anura: Ceratophryidae)

Abstract: The horned frog family, Ceratophryidae, currently comprises three genera and 12 extant species, distributed from the Caribbean lowlands to the Pampean grasslands. Horned frogs are fossorial species that are remarkable in terms of their adult and larval morphology, karyotype, behavior, and other aspects of their biology. In this paper we present a molecular phylogenetic analysis with the goals of: (1) ex- ploring the relationships among the species of Ceratophryidae; (2) studying the evolution of polyploidy; (3) studying the evolution of cocoon formation and larval development duration associated with surviving in semiarid environments; and (4) reviewing the ceratophryid fossil record that could be relevant as calibration points in molecular divergence estimations. The analysis included 11 of the 12 extant species and, when possible, multiple exemplars per species, as well as multiple outgroups. Sequence data were obtained on seven mitochondrial and six nuclear genes for up to 8200 bp per specimen. Our results indicate that the individual monophyly of Ceratophrys and Lepidobatrachus is well corroborated. The monotypic Chacophrys is recovered as the sister taxon of Lepidobatrachus, but with Jackknife frequency < 50%. Lepidoba- trachus asper is the sister taxon of L. laevis + L. llanensis. Relationships within Ceratophrys are congruent with an earlier proposal, with a clade composed of the species possessing a dorsal bony shield (Ce. aurita, Ce. cranwelli, Ce. joazeirensis, and Ce. ornata), and another clade composed of Ce. stolzmanni, Ce. calcarata, and Ce. cornuta. Unlike earlier proposals, the octoploid species (Ce. aurita, Ce. joazeirensis, and Ce. ornata) are not monophyletic, as the diploid Ce. cranwelli, and Ce. ornata are sister taxa. This result implies an ambiguous optimization of ploidy levels, with either a single origin of octoploidy with a subsequent reversal to diploidy, or two independent origins of octoploidy being equally parsimonious; both alternatives are quite unusual from the perspective of chromosome evolution. Our results suggest that ceratophryids diversified in semiarid environments and three independent events resulted in three species subsequently occupying temperate or tropical humid areas. This early diversification in semiarid areas explains the retention of characteristics associated with these environments (like the production of a cocoon of dead skin during estivation, and possibly an accelerated larval period and development) in species present in humid areas. A revision of the fossil record of this family of frogs indicates that there are only two fossil remains that could serve as calibra- tion points for molecular clock estimation, but a number of issues associated with them preclude their use.

Drivers of individual niche variation in coexisting species

Abstract: Although neglected by classic niche theory, individual variation is now recognized as a prevalent phenomenon in nature with evolutionary and ecological relevance. Recent theory suggests that differences in individual variation across competitors can affect species coexistence and community patterns. However, the degree of individual variation is flexible across wild populations and we still know little about the ecological drivers of this variation across populations of single species and, especially, across coexisting species. Here, we aimed to (a) elucidate the major drivers of individual niche variation in natural communities and (b) to determine how consistent this variation is across coexisting species and communities. We analysed natural patterns of individual-level niche variation in four species of coexisting generalist frogs across a wide range of tropical communities. Specifically, we used gut contents and stable isotopes (δ13 C and δ15 N) from frog species and their prey to quantify individual niche specialization. Then, we combined data on local community structure, availability of prey, phylogenetic relationships and predator-prey size models to test how this variation is related to four ecological factors which are predicted to be key drivers of individual specialization: intraspecific competition, interspecific competition, ecological opportunity (i.e., diversity of resources) and predation. We found that the degree of individual trophic specialization varied by up to ninefold across populations within the same species. This sizable variation in trophic specialization across populations was at least partially explained by gradients of density of competitors (both conspecifics and heterospecifics) and intraguild predation. However, the specific relationships between individual specialization and these ecological gradients were strongly species-specific. As consequences, the identity of the species with more individual variation changed among sites and there was typically no spatial correlation in the degree of individual specialization across coexisting species. Our results show that individual niche specialization within and across species can be strongly context-dependent and that hierarchies of individual variation among coexisting species are not necessarily consistent across communities. Recent theory suggests that this pattern could lead to concurrent changes in competitive interactions across sites and thereby could play a key role in species coexistence at the landscape level. Our results suggest that individual variation across and within coexisting species has the potential to affect not only species coexistence at local communities, but also regional diversity patterns.

Diet of Rhinella schneideri (Werner, 1894) (Anura: Bufonidae) in the Cerrado, Central Brazil.

Abstract: This study describes the diet of Rhinella schneideri based on the analysis of the stomach contents of 18 specimens from an area within the Cerrado, Central Brazil. We found 842 items belonging to 11 prey categories, including the plant material category. The most important prey categories for R. schneideri were Insect larvae, Coleopteran and Formicidae. Numerical and volumetric niche breadths of R. schneideri were 3.35 and 1.00, respectively. According to its diverse diet and abundance, R. schneideri may be considered a generalist and opportunist species.

Diet of two sympatric Phyllomedusa (Anura: Hylidae) species from a cacao plantation in southern Bahia, Brazil

Abstract: Abstact. We studied the diet of two sympatric species of leaf-frogs, Phyllomedusa rohdei and P. burmeisteri, captured in a cacao plantation in the Atlantic forest domain of southern Bahia, using stomach-flushing. The most important prey categories for P. rohdei were Araneae, larval Lepidoptera and Orthoptera, while for P. burmeisteri: Araneae, Coleoptera and larval Lepidoptera. Other items frequently flushed out of the frogs were plant remains, mites and skin. The snout-vent-length of the frogs was not correlated with the length and number of prey items. Our results suggest that both leaf frog species studied are opportunistic sit-and-wait predators with a high overlap in prey categories.