PPGCB https://repositorio.ufpb.br/jspui/handle/tede/4098 2026-05-04T13:03:17Z 2026-05-04T13:03:17Z Silva, Josivan Bernardo da https://repositorio.ufpb.br/jspui/handle/123456789/37858 2026-03-12T06:07:17Z 2025-03-28T00:00:00Z

Título: Estrutura da taxocenose de lagartos em uma região de dunas no semiárido brasileiro: avaliando a influência de fatores históricos e ecológicos Autor(es): Silva, Josivan Bernardo da Orientador: Mesquita, Daniel Oliveira Abstract: Studies on taxocene structure seek to understand the mechanisms responsible for species organization in natural environments. Aspects such as species richness and abundance, organism distribution, and resource use are important elements of this structure and have been the focus of ecological studies. We investigated the structure of a lizard taxocene in a dune area of the Brazilian semi-arid and analyzed the influence of ecological and historical factors on this structure. The study was conducted in the municipality of Casa Nova-BA, in the São Francisco River region. We quantified the trophic and morphological niche of the lizards in the community and subjected these data to a niche overlap analysis, revealing the degrees of overlap between each pair of species, as well as the overall taxocene overlap. We used the null model proposed by Geange (2011) to test whether resource use in the taxocene differed from what would be expected by chance. We submitted the proportions of each food item consumed by each species, as well as the mean of each morphological variable, to a phylogenetic principal component analysis (pPCA) to identify the influence of ecological and historical factors on the lizard community. The niche overlap analysis revealed the absence of trophic structure, indicating a low niche segregation among species. Additionally, a greater influence of ecological factors on lizard diet was observed. This, along with the considerable overlap values found between several species pairs, suggests that recent competition may be influencing the structure of the taxocene. The niche overlap results in the morphological dimension showed that the community is structured, with species being grouped. Eight out of ten morphological variables were responsible for niche partitioning, and the highest overlaps occurred among closely related species. The pPCA results for morphology indicated a greater influence of historical factors on the Casa Nova taxocene, highlighting a set of morphological attributes that separate lizards into distinct niche dimensions, allowing them to occupy and explore different microhabitats. This morphological pattern is similar to that found in other studies on lizard taxocenes in Neotropical regions and points to strong niche conservatism. Editor: Universidade Federal da Paraíba Tipo: Dissertação

2025-03-28T00:00:00Z Silva Neta, Aldenir Ferreira da https://repositorio.ufpb.br/jspui/handle/123456789/37714 2026-02-25T06:08:07Z 2023-09-28T00:00:00Z

Título: Ecologia evolutiva do lagarto Brasiliscincus heathi (squamata: mabuyidae): filogeografia, autoecologia e parasitismo na Caatinga brasileira Autor(es): Silva Neta, Aldenir Ferreira da Orientador: Garda, Adrian Antonio Abstract: The Neotropical region has a long history of diversification and maintenance of biodiversity. However, the processes that shaped the origin and spatial patterns of lineages are still poorly understood. The group comprising the herpetofauna has been the focus of phylogeographic studies aimed at understanding evolution, speciation mechanisms, extinction, and changes in the distribution of organisms in tropical regions. The lizard genus Brasiliscincus includes three species restricted to South America: Brasiliscincus agilis, B. caissara, and B. heathi. The main taxonomic challenge for this genus has been establishing diagnostic characters, since most of the scale characters used show high overlap between species, making it difficult to define distribution limits, origin, and evolutionary history. Thus, we used phylogeographic inferences to understand the evolutionary history of the genus Brasiliscincus (B. agilis, B. caissara, B. heathi) occurring in the Caatinga and adjacent areas. In parallel, we investigated potential variations in ecological aspects of the lizard B. heathi, including diet, reproduction, sexual dimorphism, and parasitism, in relation to its geographic distribution in the Caatinga. We collected tissue samples covering the entire distribution of all three species, totaling 135 samples, and used mitochondrial genetic markers (COI and 16S) for genetic reconstruction through Bayesian and historical-demographic analyses. BAPS identified two populations of B. heathi: the first consisting of individuals distributed north of the São Francisco River, and the second south of the river, along with an additional unknown lineage associated with high-altitude regions in Bahia. We used four lineage delimitation methods, and except for ASAP, all others recovered six lineages within the complex. To infer aspects of the natural history and parasitism in B. heathi, we examined 293 individuals from 48 localities in the Caatinga. We identified 14 prey categories, with the index of relative importance ranging from 0.15 to 25.62. Random Forest analysis selected snout-vent length (SVL) and limb spacing as the most important variables for distinguishing sexes based on body shape. Regarding reproductive aspects, results show a positive relationship between female SVL and the number of embryos. In terms of parasitism, we found 339 endoparasites, with an overall prevalence of 57.44%. Mean abundance was 2.39 ± 0.31, range (0–21), and mean infection intensity was 4.79 ± 0.48 (1–22). North of the São Francisco River, we observed higher species richness (5 spp.), with Oochoristica sp. and Parafaringodon hispidus being the most prevalent. GLM models showed that SVL was the most important variable for endoparasite abundance across the entire sample, and Oochoristica sp. abundance was influenced by both sex and geographic group. Four species of endoparasites represent new records for the host. Editor: Universidade Federal da Paraíba Tipo: Tese

2023-09-28T00:00:00Z Santana, Erika Flávia Crispim de https://repositorio.ufpb.br/jspui/handle/123456789/37677 2026-02-21T06:06:04Z 2020-10-30T00:00:00Z

Título: Comunidades bentônicas recifais do Atlântico Sul Ocidental: estrutura, distribuição espacial e influência de variáveis ambientais Autor(es): Santana, Erika Flávia Crispim de Orientador: Francini Filho, Ronaldo Bastos Abstract: Brazilian reefs are unique in the world due the high abundance of fleshy macroalgae and turf algae and low richness of reef-building corals. Environmental (e.g. seawater temperature, light availability) and spatial drivers (e.g. depth, offshore distance) are responsible for structuring the benthic marine communities. It is believed that shallow to mesophotic reefs are differently influenced by abiotic drivers, particularly light and temperature, which limit/modify the organisms’ occurrence and abundance on reefs. While few Brazilian corals prefer shallow waters with high temperatures and direct incidence of light, but most of them show preference for turbid waters and deeper zones, as they uptake attenuated light. Considering this, the present study used powerful classifications tools to address the following aims: 1) to identify and boundary discrete shallow benthic communities (0-30m) in coastal and oceanic reefs, as well as identifying their main environmental drivers, 2) to determine the threshold (i.e. transition) between shallow and deep benthic communities (30- 60m), using the Brazilian oceanic islands as a model and 3) to understand the influence of local biotic (i.e. contact interactions) and environmental factors on the large-scale patterns of basal bleaching (i.e. out of years with anomaly) of the three most abundant and important reef-building corals in Brazil Siderastrea spp., Mussismilia hispida e Montastraea cavernosa. As a result, benthic communities and environmental variables (remote-sensing data) were obtained for 18 sites (14 coastal and 4 oceanic), representing the most complete database of abundance of benthic reef organisms for Brazil. Ten distinct benthic communities were identified for both coastal and oceanic reefs, which are dominated by turf algae and fleshy macroalgae. The turbidity was the main environmental driver responsible for the two types of shallow reef communities: i) in warm waters reefs (dominated by macroalgae), ii) another with turbid water (dominated by turf algae). Geographical drivers also influenced the distribution of shallow and mesophotic benthic communities. Depth and temperature had a significant influence on the distinction between shallow reef and mesophotic benthic communities at the oceanic islands, with five distinct communities being identified. The threshold between the shallow and deep communities was 12.5 m, and no significant changes were recorded up to 30 m depth, as previously indicated. The highest incidence of coral bleaching occurred in shallow and well-illuminated (euphotic) oceanic reefs, corroborating the preference of the most corals for shaded coastal and/or deep habitats. The results showed that the use of classification tools is useful for studies of benthic reef communities along the large spatial scales and for understanding the environmental drivers governing them. In addition, they provide important data on the health of Brazilian corals in years without thermal anomalies, which represent an important baseline for future assessments of the impacts caused by mass bleaching events in the Southwestern Atlantic reefs. Editor: Universidade Federal da Paraíba Tipo: Tese

2020-10-30T00:00:00Z Silva, Ricardo Marques da https://repositorio.ufpb.br/jspui/handle/123456789/37646 2026-02-18T06:05:52Z 2019-05-29T00:00:00Z

Título: Filogeografia, limites específicos e história evolutiva de duas espécies de anuros no domínio da Caatinga Autor(es): Silva, Ricardo Marques da Orientador: Garda, Adrian Antonio Abstract: Unveil the patterns and processes of diversification of the Neotropical biota has been the challenge of biogeographers for decades. With the rise of molecular methods, phylogeography is a powerful method that combines genetic data and the biogeography of organisms. Among herpetofauna, aquatic dependence and low dispersive capacity are requirements attributed as a justification for amphibians not having a wide distribution. In this context, biologically distinct species, but with a similar distribution may respond differently to the same historical-demographic processes and environmental barriers. Thus, we used phylogeographic inferences to compare the evolutionary history of Corythomantis greeningi and Rhinella jimi in the Caatinga and adjacent areas. We collected tissue samples covering the entire distribution of both species and used a multilocus approach, sequencing mitochondrial and nuclear genes (five for C. greeningi and four for R. jimi). We use genetic, historical- demographic reconstructions and ecological niche modeling for both species. We obtained 98 sequences for C. greeningi and 135 for R. jimi. Bayesian mitochondrial gene tree reconstruction recovered structure only for C. greeningi, associated with the Espinhaço Mountain Range. Population assignment recovered three populations for C. greeningi with sharing of haplotypes between two of them, while R. jimi recovered only a widely distributed population. We tested the populations of C. greeningi using coalescent delimitation methods (BPP) and found that the population associated with Espinhaço is a new species of Corythomantis. The same analysis attested to the taxonomic validity of R. jimi, but haplotypical reconstructions showed sharing of haplotypes between R. jimi and two phylogenetically close species: R. marina and R. diptycha. We tested six diversification scenarios with approximate Bayesian computation for Corythomantis and the best model indicates divergence of the new species at the beginning of the Pliocene, and population expansion and gene flow among C. greeningi populations. Historical-demographic inferences also showed population changes in R. jimi during the Pleistocene. Finally, we describe a new species of Corythomantis restricted to the Espinhaço Chain. The new species substantially differs from C. greeningi genetically, morphologically and acoustically. Editor: Universidade Federal da Paraíba Tipo: Tese

2019-05-29T00:00:00Z