https://repositorio.ufu.br/handle/123456789/5482 Thu, 16 Jul 2026 12:23:34 GMT 2026-07-16T12:23:34Z https://repositorio.ufu.br/handle/123456789/48870 Title: Estrutura e função dos pneumatódios em raízes de Vanda híbrida (Orchidaceae): do macro ao micro Abstract: The aerial roots present in Orchidaceae have anatomical characteristics that are efficient in optimizing the acquisition and use of water and nutrients. Among them, the formation of the velamen stands out, a simple or multiple epidermis, consisting of cells that die at maturity, which allows orchids to survive in environments with water scarcity or fluctuation. Some species have pneumatodes in the velamen. The aeration units correspond to a set of cells that include the region of the velamen above the aeration cells (the pneumatode), the aeration cells themselves, and the specialized cells of the cortex. The functioning of the aeration units is based on two non-exclusive hypotheses involving passive mechanisms. In this sense, this thesis is based on the central hypothesis that structural, chemical, and physiological variations directly influence the functional performance of the aeration units, modulating their efficiency and response to environmental conditions. It is structured in three chapters. In the first chapter, we propose that the functionality of the aeration units is anchored in the chemical composition of the walls of their different cell types and the rest of the canopy, which depends directly on the composition of their cell walls and adjacent layers, allowing dynamic adjustments in the opening and closing of the aeration channels in response to environmental variations. In the second chapter, we analyze the tolerance of the epiphytic hybrid Vanda subjected to flooding, determining whether the water saturation of the canopy leads to root oxidative stress with a systemic effect on plant metabolism, discussing the role of pneumatodes in root aeration. In the third, we present a summary of the results obtained in the form of scientific dissemination through a brochure, as well as an account of the author's academic experience, emphasizing the importance of pursuing a doctorate and valuing the educational path. Thu, 30 Oct 2025 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/48870 2025-10-30T00:00:00Z https://repositorio.ufu.br/handle/123456789/48737 Title: Reversão sexual em peixes Acanthomorpha: distribuição espacial e relacional entre as comunidades Abstract: To think of sex and its associated phenotypic traits as something static, invariant, is an obsolete mentality and incoherent with the evolutionary scenarios that point to multiple origins and convergences of hermaphroditism and sexual reversal among vertebrates. Hermaphroditism is associated with genetic factors and responses to environmental and social stimuli, where phenotypic sexual expression occurs through synchronous or sequential pathways. Sex reversals are classified as protogynous, protandrous or bidirectional. Among vertebrates, the teleost fish (clade Actinopterygii) are the only group to present sex reversal as an evolutionary strategy with multiple independent origins and convergences. A more inclusive and diverse lineage within Teleostei is defined by the clade Acanthomorpha, who has the greatest diversity of sexual strategies, including the most complex sex reversal mechanisms among hermaphroditic fish. This study reviews the literature and explores the global spatial distribution of hermaphroditic bony fish allocated in the specious clade Acanthomorpha with synchronous or sequential sex reversals in marine and freshwater environments. The purpose was to compile information on hermaphroditic fish, their most frequent modes of sex reversal and their respective global geographic distributions to investigate general patterns of sexual evolution in vertebrates and the biogeographic regions that exert extraordinary influences on the structuring of hermaphrodite communities. A literature review was performated to obtain the necessary information about the hermaphroditic species in Acanthomorpha, including: the diversity of valid species, sex reversal strategies and geographic distributions in marine and freshwater biogeographic regions. All information collected was extracted from the literature by searching articles, books and museum catalogs. The geographic distributions of the species were inferred through datasets obtained from metadata repositories available online. In possession of such cleaned dataset, the spatial structuring of communities of hermaphrodite acanthomorphs was investigated using network theory with two different clustering algorithms. As a result, an extensive list was prepared with 223 hermaphroditic species, being 213 marine and 10 freshwater. Of these species, 26 are synchronous hermaphrodites and 197 are sequential hermaphrodites. Among sequential hermaphrodites, 151 are protogynous, 28 are protandrous, and 18 are serial bidirectional. Hermaphrodite acanthomorphs are widely distributed around the planet, occurring in all biogeographic realms, except Subarctic America. They are most diverse in tropic marine regions, with an extraordinary presence in shallow seas with coral reefs in the Indian Ocean (i.e., Indo-Malay and Australasian regions). There is a spatial structuring of hermaphroditic fish communities inhabiting different biogeographic realms, however the number of communities depends on the chosen algorithm. Common between the two algorithms is the existence of a community in the Americas and another distributed in the southern Eurasia, Central and Eastern Eurasia, Afrotropics, Indomalia and Oceania. The diversity of hermaphrodite acanthomorphs in Antarctica is low (e.g., 1 species), so there is no viable hypothesis on the spatial structuring in this region. Depending on the clustering algorithm, communities of hermaphroditic acanthomorphs of the Nordic seas, such as those present in the realms of Western Eurasia and Subarctic Eurasia, form independent communities or cluster with kingdoms located to the east of the planet. Wed, 30 Nov 2022 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/48737 2022-11-30T00:00:00Z https://repositorio.ufu.br/handle/123456789/48726 Title: Atributos da história de vida do cachorro-do-mato (Cerdocyon thous): sazonalidade reprodutiva, tamanho de ninhada e investimento parental em uma região antropizada no Brasil Central Abstract: Life history comprises the set of organismal traits that maximize reproductive success. Attributes such as age and body size at first reproduction, litter size, and parental care are central to evolutionary trade-offs. Understanding the processes shaping these patterns in carnivorous mammals is challenging due to their elusive behavior, large home ranges, and low population densities. This study describes life-history attributes of the crab-eating fox (Cerdocyon thous) in Central Brazil, focusing on reproductive seasonality, litter size, and parental investment. Data were collected between 2010 and 2024 in human-modified landscapes in southeastern Goiás. The breeding season was used as a characteristic of the reproductive cycle to explore a life-history attribute, parturition, which was estimated based on records of pregnancy, lactation, and GPS radio-collar monitoring. Pups were counted when first observed outside dens, with camera traps deployed to assist in monitoring offspring. Body mass data of females and males, as well as female reproductive condition classified as primiparous or multiparous, were related to litter size. Parental investment was assessed through photographic records of adults carrying food and the simultaneous presence of adults and pups. A total of 63 records of female reproductive condition were obtained, including 23 pregnant and 40 lactating females. Pregnant females were observed between June and November, with a peak in July, whereas lactating females predominated between August and November, peaking in September. Estimates of parturition based on 14 independent records indicated events between June and September, with a mean in August, corroborating the expected reproductive seasonality. Nineteen litters were recorded, with a mean of 3,1 pups (sd = 1.6; range: 1–6). We obtained 60 records of adults with pups and 65 records of adults carrying food. Adults carrying food were observed between July and November, and family groups between December and April, indicating that pups remain with their parents for approximately nine months. The observed reproductive seasonality may be associated with greater resource availability during early life stages, which coincide with the end of the dry season and the onset of the rainy season, as well as with prolonged parental care. The description of these reproductive parameters provides robust information on the ecology of the crab-eating fox and is fundamental for understanding the diversity of reproductive strategies within the family Canidae. Additionally, the natural history data presented here contribute to understanding factors influencing population parameters of this species and those with whom it interacts, supporting conservation decision-making, particularly in anthropogenic environments. Fri, 31 Oct 2025 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/48726 2025-10-31T00:00:00Z https://repositorio.ufu.br/handle/123456789/47981 Title: Eficácia de poleiros artificiais na restauração ambiental: análise da cobertura vegetal e da avifauna após dez anos de implementação Abstract: Habitat fragmentation and degradation in the Cerrado compromise ecological dynamics and the maintenance of biodiversity, requiring strategies for environmental restoration. Artificial perches can be used as a nucleation technique capable of attracting disperser birds and increasing seed rain, which in turn favors natural regeneration. The present study evaluated the effectiveness of artificial perches ten years after their implementation in a Cerrado sensu stricto area in the Triângulo Mineiro region (MG), investigating the relationship between vegetation cover, estimated through the Normalized Difference Vegetation Index (NDVI), and bird community composition. Birds were sampled using linear transects during twelve monthly campaigns between 2024 and 2025, comparing two transects: A – artificial perches implemented/removed more than 10 years ago, and B – without the implementation of any nucleation technique. A total of 115 species distributed across 33 families were recorded, with a predominance of Passeriformes, particularly Tyrannidae and Thraupidae. Guild analysis revealed a predominance of insectivores (40,8%), followed by omnivores (22,6%) and frugivores (12,1%). The species accumulation curve did not reach stabilization, with the Chao2 estimator indicating that 87% of the local avifauna was recorded. Comparison with the previous study, considering only transect A, revealed an increase in frugivorous (5) and nectarivorous (3) species, indicating a qualitative improvement of the sampled area. When considering both transects evaluated in this study (A+B) and the previous study, the total richness of the area is 134 bird species. The NDVI showed an increase in transect A compared to 2014 values (0.286 vs. 0.244), suggesting vegetation densification associated with the presence of artificial perches. The results demonstrated that such structures played a relevant role in ecological restoration, promoting increased vegetation cover and favoring the return of specialized bird guilds. It is concluded, therefore, that artificial perches can be effective tools in nucleation processes and should be considered in environmental recovery strategies in the Cerrado of Minas Gerais. Thu, 23 Oct 2025 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/47981 2025-10-23T00:00:00Z