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Variabilidade fenotípica e genética de Kinosternon scorpioides (Linnaeus, 1766)

2019-01-01T00:00:00Z

Título: Variabilidade fenotípica e genética de Kinosternon scorpioides (Linnaeus, 1766) Abstact: The Kinosternon scorpioides species is a small freshwater chelonian distributed throughout the Americas, and in Brazil mainly in the north and northeast regions. With the average goal of morphological and genetic changes in Brazil and Colombia, used as traditional and geometric morphometric techniques, in addition to molecular analyzes (mitochondrial and nuclear DNA). All samples sampled have phenotypic characteristics typical of the species, color, organization and quantity of chemical plates. Linear morphometry indicates that there is a statistical difference between sex, with males being narrower and shorter in relation to females, while geometric morphometry shows shape variation for each sex. In relation to the evaluation between the variations, from the geometric morphometry, these are organized in groups, selected according to the sampled geographic regions, those that are close to each other and share or even format. The genetic study indicates that Brazilians are different from Colombians, with an average genetic diversity of 3% (mtDNA). This variation was accompanied by the results of the microsatellites, with the FSt fixation index and initial coefficient, in addition to revealing what these statistics are structured, with low inbreeding rates. The results are important for the knowledge of the Brazilian species K. scorpioides, and other subsidiary studies on conservation and conservation.

Sistemática de leporinus (characiformes, anostomidae) a partir de ferramentas moleculares e morfológica

2024-04-12T00:00:00Z

Título: Sistemática de leporinus (characiformes, anostomidae) a partir de ferramentas moleculares e morfológica Abstact: The genus Leporinus includes around 80 valid species, grouping the largest number of species within the Characiformes order and being the most diverse within the Anostomidae family. The species are widely distributed in river basins in the Neotropical region, but it is a fact that it is difficult to understand the biodiversity of the genus Leporinus, i.e. the specific limit, because the morphological patterns are very similar between the species of this genus, as are the phenotypic characteristics observed in juvenile and adult individuals. This study used mitochondrial and nuclear genome sequences and morphological data to identify and provide the kinship relationships of the Leporinus species, thus contributing information that should be used in the species' management and conservation plans. The integrative study using morphological and molecular data made it possible to record Megaleporinus macrocephalus in the Maranhão river basins, representing an important extension of its distribution, which is now confirmed in the Itapecuru and Mearim river basins. The analysis of 157 Leporinus COI gene sequences from the Itapecuru, Mearim, Turiacu, Pericumã, Periá, Preguicas, Parnaíba and Tocantins river basins identified L. maculatus, L. unitaeniatus, L. affinis and L. piau (from the Parnaíba river) as distinct groupings corroborated by species delimitation methods, which revealed the presence of four distinct MOTUs corresponding to each of these species. The bPTP method restricted L. venerei to a single MOTU, pointing to the first occurrence of this species in rivers in Maranhão. There was also evidence of the separation of L. cf. friderici into two clades and the subsequent formation of different MOTUs, which is therefore consistent with the polyphyly of this species indicating the existence of cryptic diversity, as well as the configuration of L. cf. friderici and L. piau into two clades supporting the conclusion that the specimens of L. piau from Maranhão were misidentified. In the investigation of cryptic diversity in L. piau from the Maranhão and Piauí river basins, using mitochondrial and nuclear markers, two well-supported groups were observed, in which specimens from the Itapecuru, Mearim, Turiaçu and Pericumã rivers were assigned to an unnamed clade, representing relatively ancient diversification and probably hiding cryptic diversity. The second group included specimens from the Parnaíba and Mearim rivers, called L. cf. friderici sensu stricto, a group that diversified relatively recently and is more closely related to L. friderici from the type locality. The results confirmed the existence of a complex scenario of cryptic diversity in the Leporinus genus and the taxonomic inconsistencies found in this group of fish.

Contribuições à sistemática do gênero Artibeus Leach, 1821 (Chiroptera, Phyllostomidae) com base em dados morfológicos e moleculares: implicações para evolução e conservação

2025-06-25T00:00:00Z

Título: Contribuições à sistemática do gênero Artibeus Leach, 1821 (Chiroptera, Phyllostomidae) com base em dados morfológicos e moleculares: implicações para evolução e conservação Abstact: The genus Artibeus has been the subject of extensive debate regarding its systematics, which remains complex and controversial, primarily due to insufficient information and significant variation across different taxa within the group. This study integrates two complementary approaches to investigate the taxonomy, systematics, and population dynamics of Artibeus in Brazil. The first part of the research employs an integrative analysis using morphological, molecular, and geometric morphometric data to elucidate intra- and interspecific relationships among species of the genus. In this study, we generated two datasets: one based on molecular species delimitation using the barcode region (COI) and another incorporating cranial size and shape data analyzed through Geometric Morphometrics (GM) methods. The species delimitation results identified molecular operational taxonomic units (MOTUs) that align with the morphological identification of the species. GM analyses revealed significant inter- and intraspecific variation in cranial size and shape among Artibeus species. The combined results suggest a lack of a strong phylogenetic signal driving skull variation. This finding indicates that historical ecological factors may have played a key role in shaping cranial morphology, acting as selective pressures across geographic space and contributing to intraspecific variation in Artibeus planirostris. The second part of the study investigated the population genetic structure of A. planirostris using mitochondrial markers with extensive sampling. Our findings reveal substantial genetic differentiation among populations, with limited gene flow, particularly in peripheral regions compared to northern South America. This suggests that local adaptations, shaped by specific environmental pressures and Pleistocene climatic fluctuations, may have influenced the dispersal and colonization capacity of A. planirostris in these areas. These findings support the hypothesis that isolation by distance may also contribute to the observed distribution pattern. The demographic history of A. planirostris indicates a recent population expansion during the Late Pleistocene, approximately 50,000 to 60,000 years ago.

Biomarcadores em Ucides cordatus (Linnaeus, 1763), desenvolvimento de bio-ontologia e aplicativo para monitoramento de impactos ambientais em regiões portuárias do Maranhão

2024-11-25T00:00:00Z

Título: Biomarcadores em Ucides cordatus (Linnaeus, 1763), desenvolvimento de bio-ontologia e aplicativo para monitoramento de impactos ambientais em regiões portuárias do Maranhão Abstact: This study aimed to use biomarkers in Ucides cordatus (Linnaeus, 1763) as a basis for the development of a bio-ontology and an application to monitor environmental impacts in port regions of Maranhão. In 2021, male specimens of U. cordatus (caranguejo-uçá) were captured quarterly in the mangroves of the Port Complex of São Luís - MA (through the bracing technique) at two different points: P1 located between two ports in the industrial region of São Luís (where there is an intense flow of small and large vessels, due to port and fishing activities); P2 which is close to an important fishing and tourist port in the region subject to human interference (effluents, solid waste and vessel engine oil). Biometric measurements were recorded from the specimens and the gills and hepatopancreas were extracted for histological analysis and enzyme activity (catalase – CAT and glutathione S-transferase – GST). Gills, hepatopancreas and edible tissue of the crabs were also collected for analysis of metals (Al, As, Cd, Cu, Cr, Fe, Pb, Mn, Ni and Zn). In the field, water and sediment samples were collected for analysis of the content of metals and other elements (Al, As, Cd, Cu, Cr, Pb, Hg, Mn, N, Ni, P and Zn). The results for the abiotic parameters showed values in accordance with the legislation for both areas. Al, P, Mn and Zn were found at levels above those permitted in the water. All elements found in the sediment were higher in P1. In general, the elements in the tissues were concentrated in the order: Fe>Al>Zn>Cu>Mn>Ni>Cr>Pb for point P1 and Al>Fe>Zn>Cu>Mn>Ni>Cr>Pb for point P2. Changes in CAT and GST activities were found in crabs from both areas, with the gills showing the highest activity (p < 0.05), as they were in direct contact with the contaminant (acute response). The results showed higher values of histological lesions in P1, but it was observed that the damage to the organ was similar between the areas. The lesions classified as irreversible were found in large numbers in organisms captured in P1, compromising the functioning of the organ and the health of the organisms residing in this region. More severe histological changes were observed in the hepatopancreas, with the organ best demonstrating the history of contamination. The biomarker information served as a basis for the construction of the bio-ontology with the biomonitor species. The evolution of the ontology has helped to connect concepts, facilitating the understanding of the stress of the estuarine environment where port activities are located. This reinforces the usefulness of the bio-ontology for environmental monitoring in port regions. The Crab Monitor software was created and will act to better share and access information, in a more effective approach to biomonitoring of port regions with native species. Based on the results obtained, it is concluded that the bio-ontology and the Crab Monitor software can assist in the continuous and predictive monitoring of port and industrial regions.