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Autoalelopatia da polpa funicular de um cacto colunar que ocorre em diferentes ecossistemas do Nordeste do Brasil

2026-01-08T16:36:23Z

Título: Autoalelopatia da polpa funicular de um cacto colunar que ocorre em diferentes ecossistemas do Nordeste do Brasil Autor(es): Santos, Bruno de Santana Abstract: The funicular pulp of fruits present in some Cactaceae is known to inhibit the germination of their own seeds. Furthermore, it has been reported in the literature that fruits can produce toxic or deterrent metabolites, often found in higher concentrations and diversities than in other plant organs, thus being able to prevent the germination of their own seeds. However, it has not yet been described in the literature how environmental conditions can influence the dynamics of this autoallelopathic effect. Therefore, the general objective of this dissertation was to evaluate the autoallelopathy of the funicular pulp of a columnar cactus that occurs in different ecosystems of Northeastern Brazil. We used as a study model the species Pilosocereus catingicola (Gürke) Byles & Rowley subsp. salvadorensis (Werderm.) Zappi (Cactaceae), which occurs in areas of Caatinga, a semiarid region of Northeastern Brazil; and in areas of Restinga, in the Brazilian coastal region. Furthermore, this columnar cactus species produces its fruits in the dry and rainy seasons. To achieve the general objective of this dissertation, this work was divided into two chapters. In the first chapter, the objective of the work was to perform the metabolite profile of the mucilaginous funicular pulp of the fruits of P. catingicola subsp. salvadorensis using the non-targeted metabolomics technique by Gas Chromatography coupled to Mass Spectrometry. The results for this chapter, it was possible to note 135 metabolites belonging to 19 chemical families. In addition, it was possible to conclude that environmental conditions directly influence the metabolism of the funicular pulp of the fruits of P. catingicola subsp. salvadorensis in different ecosystems, with the variations observed here being related to seasonality, resulting in differences between populations of the same species. In the second chapter of this dissertation, the objective of the work was to evaluate how seasonality and the ecosystem of occurrence influence the autoallelopathy exerted by the funicular pulp of the fruits of P. catingicola subsp. salvadorensis on the germination behavior of its seeds. The results for this chapter showed that the seeds produced in the rainy season, in both populations, presented higher germinability, shorter germination time and greater synchrony, with less uncertainty and variation in the germination process. However, the extracts of lower polarity (AcOEt and Hex) negatively influenced the germination behavior as the concentrations increased during the rainy season, for both populations. Therefore, we can conclude for this chapter that the effect of autoallelopathy is dynamic in nature, being influenced by the fruit production seasons and the ecosystem in which these populations are inserted. The results found in this dissertation provide a comprehensive view of the metabolic responses of this species to environmental conditions, highlighting its adaptive capacity and the role of seasonal conditions in directing its metabolism. In this context, extractions performed with different organic solvents revealed significant variations in the concentrations of compounds between seasons and populations, demonstrating that seasonality not only regulates metabolic synthesis, but also influences the distribution and predominance of metabolites, adjusting them to the environmental conditions of each period, influencing the autoallelopathic effect differently.

Uso do espaço vertical por marsupiais (Didelphimorphia: Mammalia) através da utilização de ninhos artificiais em um fragmento de floresta atlântica

2026-01-07T19:35:31Z

Título: Uso do espaço vertical por marsupiais (Didelphimorphia: Mammalia) através da utilização de ninhos artificiais em um fragmento de floresta atlântica Autor(es): Santos, Amanda Teixeira dos Abstract: Different sampling methods have been developed to analyze space use and vertical stratification by mammals. The artificial nesting technique allows the analysis of the activities and use of these refuges by animals without influencing their behavior. In this study, the use of vertical space by marsupials was characterized by the use of artificial nests in an area of the Atlantic Forest in Sergipe, Northeastern Brazil. This study also presented unprecedented data on the use of plant resources in the construction of these nests. Sampling was realized at two sampling sites, with 60 capture stations/site arranged with two artificial nests at 1.5 m and 3 m high. The nests were monitored biweekly between April/2022 and May/2023. The formats of the occupied shelters were defined in terms of the organization of the plant material. Differences in records between the vertical strata of each species and between the strata and species were tested. Vertical segregation was measured using the niche overlap. The relationship between precipitation and the number of occupied nests/month, as well as the relationship between the animal's body size and the area of the shelter constructed, was investigated. The variation in the number of shelters built among the four types (cocoon, shell, few leaves, and vertical leaves) for each species was evaluated. In some cases, green leaves were recorded from 125 shelters with dry leaves. Only 24 nests were occupied (19.2%), one of which had two sub-adult individuals of Marmosa murina. Marmosa demerarae was more frequent at 3.0 m while M. murina did not differ in the use of strata. The frequency of nests records between the strata differed among these species. A high niche overlap was recorded (0.834). Leaves belonging to the families Rubiaceae (in 100% of the nests), Melastomataceae, Phyllanthaceae, and Erythroxylaceae were identified. There were no differences between the different types of shelters built by the species. There was no relationship between monthly nest occupancy and precipitation or between the animal's body size and the built area. In general, M. demerarae and M. murina use artificial nests in the two selected strata and build shelters with preferably dry leaves. Furthermore, the use of leaves corroborates with other studies that indicate the use of plant material by these animals. However, there appear to be no specific selection criteria with for the random use of leaves from the ground. The record of M. murina individuals in the same nest may indicate early formation of pairs or cooperative construction to increase protection. The use of Rubiaceae leaves in all shelters may be related to their wide representation of the location. The construction of the “cocoon” shelter by M. murina suggests increased protection against predators, whereas M. demerarae appears to have used its shelters more than once. Field observations indicated that shell-type shelters and with few leaves at the bottom corresponded to the initial formation of the cocoon-type nest construction process. These results contribute to increasing knowledge on the marsupials of Sergipe, and this is the first study to characterize the composition of the plant material used in these animal shelters.

O ácaro Varroa destructor e as abelhas africanizadas: uma abordagem morfométrica da relação entre parasito e hospedeiro

2026-01-07T17:52:37Z

Título: O ácaro Varroa destructor e as abelhas africanizadas: uma abordagem morfométrica da relação entre parasito e hospedeiro Autor(es): Rocha, Paloma Quirino Abstract: The Varroa destructor mite, a significant parasite of Apis mellifera bees, is subjected to a range of environmental pressures, encompassing climatic conditions and host defenses, such as hygienic behavior. Morphological analysis enables the quantification of morphological variations within and among populations, facilitating the inference of their underlying causes. Additionally, assessing fluctuating asymmetry measures the degree of stress encountered during organism development. The evaluation of these two parameters in mites can contribute to a comprehensive understanding of their adaptive strategies. The objectives of the present study were (1) to identify anatomical structures that more precisely capture morphological variations and fluctuating asymmetry in V. destructor; (2) to assess the relationship between the level of hygienic behavior in Africanized bee colonies (A. mellifera) and the morphology of V. destructor, as well as the correlation between fluctuating asymmetry in the host and parasite across different colony types. Mites and Africanized bees were collected from colonies exhibiting varying degrees of hygienic behavior in apiaries located in the Atlantic Forest and Caatinga regions. The analysis of bees involved the examination of their front wings, while mites were scrutinized based on their ventral shields, specifically the metapodal shields and genito-ventral shield. In the first chapter, V. destructor shields were identified that most accurately reflect variations in shape (crossvalidation discriminant analysis) and size (t-test) and the fluctuating asymmetry of shape and size (Procrustes ANOVA and t-test). The pair of mite metapodal shields presented the highest group classification rates, based on shape, by cross-validation, between locations (78%) and types of host colony (70%). Among colony types, it was the only one that showed differences in size between groups (p<0.001). It was also the only shield that allowed the analysis of fluctuating asymmetry of shape and size. The plate seems more suitable to reflect morphological differentiation and fluctuating asymmetry, and is recommended as a standard structure for future research. In the second chapter, we investigated the relationship between the level of hygienic behavior in bee colonies and the morphology of V. destructor mites, as well as the connection between fluctuating asymmetry in the host and parasite across different colony types. Notably, significant differences were observed in both the shape (p<0.001) and size (p<0.001) of mites infesting different colony types, particularly in the metapodal shield. Mites from hygienic colonies exhibited smaller sizes, suggesting distinct developmental pressures experienced by the two parasite groups. Moreover, variations were identified in the fluctuating asymmetry of both bee (p<0.01) and mite (p<0.01) structures. An inverse correlation was observed in the fluctuating asymmetry of size between host and parasite structures; bees from hygienic colonies exhibited higher rates of fluctuating asymmetry, while their associated mites demonstrated lower levels. These findings indicate that factors beyond hygienic behavior may exert a more significant influence on fluctuating asymmetry within the host-parasite relationship.

Composição e estrutura de uma taxocenose de serpentes em remanescente de Mata Atlântica de uma região metropolitana do Nordeste do Brasil

2022-10-05T16:26:49Z

Título: Composição e estrutura de uma taxocenose de serpentes em remanescente de Mata Atlântica de uma região metropolitana do Nordeste do Brasil Autor(es): Cardoso, Gabrielle de Souza Abstract: Assemblage composition and structure are determined by interactions between ecological and biogeographical processes. Snakes ecology and diversity patterns are reflected in morphological attributes and natural history, covering information about diet, substrate usage and daily activity. In this study were evaluated composition and natural history, morphological phylogenetic struture and urbanization effects on snakes assemblage from São Cristóvão – SE, on an Atlantic Forest remnant surrounded by urban matrix. On assemblage were registrated 27 snake species which most has environmental plasticity and wide geographical distribution. Added to low availability of vegetation strata, these factors influence the predominance of species that exploit terrestrial substrates and diet generalists. Influence of urban matrix were not observed on biogeographic similarity and phylogenetic diversity indexes, which are possibly determined by spacial clustering in the biome. Composition and phylogenetic diversity of São Cristóvão assemblage are similar to other areas in Atlantic Forest, including protected areas for conservation, and biogeographic similarity is greater with those ones of Northern portion of the biome. Morphological structure of São Cristóvão is influenced by both phylogeny and ecology, being possible visualize groupings regarding substrate usage, similar to patterns previously observed in Caatinga and Cerrado. These results show the importance of incorporating historical processes in studies of snakes assemblages and considering urban areas as study object, which makes possible understand biodiversity and how assemblages are structured in areas with environmental disturbances.