http://hdl.handle.net/11422/33 2026-07-30T10:24:09Z http://hdl.handle.net/11422/29858 Title: Influência de Estressores Associados às Mudanças Climáticas no Desenvolvimento Larval de Platynereis dumerilii (Annelida: Nereididae) Author(s)/Inventor(s): Fonseca, Lucas Alves da Advisor: Ruta, Christine Abstract: Changes in oceanic patterns driven by global climate change have especially affected the early life stages of marine organisms. Considering the scarcity of knowledge regarding the early development of annelids under the effects of climate change and their susceptibility, the present study aims to evaluate the isolated and synergistic effects of temperature and salinity on early development, survival, and the occurrence of morphological abnormalities in Platynereis dumerilii larvae. Three laboratory experiments were conducted: (i) salinity, with treatments of 35 (control), 30, and 25 at 18 °C; (ii) temperature, with treatments of 18 °C (control), 25 °C, 30 °C, and 35 °C at a constant salinity of 35; and (iii) a synergistic experiment, with seven combinations between 18 °C and 35 °C and salinities of 35, 30, and 25. The larvae were obtained through spontaneous fertilizations synchronized with the lunar cycle. Larval development was monitored up to the nectochaete stage. The results indicated that moderate temperatures (25 °C and 30 °C) accelerate development, while reduced salinities (25) cause significant delays and an increase in the incidence of morphological abnormalities. Exposure to 35 °C resulted in total mortality, suggesting a thermal limit for the species. In the combined treatments, moderate conditions favored development, while extreme combinations (35 °C/25) were lethal. The findings contribute to advancing knowledge on the responses of soft-bodied marine invertebrates to climate change, particularly within the phylum Annelida, an area still underexplored compared to studies on calcifying organisms and may serve as a reference for future experimental studies. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação 2025-07-18T00:00:00Z http://hdl.handle.net/11422/29856 Title: Efeitos das mudanças climáticas na capacidade de regeneração de Platynereis dumerilii (annelida: nereididae) Author(s)/Inventor(s): Gutiérrez, Delfina Advisor: Ruta, Christine Abstract: Anthropogenic climate change affects marine environments through alterations in salinity, rising temperatures, and ocean acidification. Understanding the effects of these factors on organisms is essential, although groups such as annelids remain underrepresented in research. The annelid Platynereis dumerilii stands out as an experimental model and exhibits posterior regenerative capacity, a key process following physical damage but potentially associated with fitness costs. This study evaluated the effects of projected variations in salinity, temperature, and pH, based on IPCC (2019, 2023) scenarios, on the regeneration of P. dumerilii. Temperatures of 18°C (control), 25°C, 30°C, and 33°C; salinities of 35 (control), 30, and 25; and pH values of 7.9 (control) and 7.6 were tested. Organisms with 30–40 segments and 3–4 months of age were amputated and monitored for five days, a period sufficient for complete regeneration under control conditions. Regeneration occurrence, survival, and the formation of anomalies were analysed using Generalized Linear Models. Results revealed that the regeneration of P. dumerilii is sensitive to future climate scenarios. Reduced salinity slightly delayed regeneration without affecting survival or inducing anomalies. Elevated temperature accelerated regeneration but caused anomalies at 30°C and mortality above this threshold. Lowered pH reduced survival and suggested a decelerating effect on regeneration. This study contributes to the understanding of climate change impacts on marine invertebrates and expands current knowledge on regeneration in annelids. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação 2025-09-19T00:00:00Z http://hdl.handle.net/11422/29767 Title: Posicionamento taxonômico e variação geográfica de populações do gênero Amerotyphlops (Serpentes: Typhlopidae) das restingas da porção norte do estado do Rio de Janeiro Author(s)/Inventor(s): Lopes, Leonardo Victor de Souza Advisor: Passos, Paulo Gustavo Homem Abstract: Amerotyphlops (Serpentes: Typhlopidae) comprises 19 species that occur in the continental portions of Central and South America, as well as insular parts of Grenada, Saint Vincent and Grenadines, and Trinidad and Tobago. In Brazil, there are currently 11 recognized species of Amerotyphlops, four of which were recently described. The present study investigated the taxonomic position of Amerotyphlops populations that occur in restinga areas in the northern part of Rio de Janeiro and southern part of Espírito Santo States. The external morphology (meristic data, morphometrics, color patterns) and internal morphology (hemipenes) of representative samples from these regions were examined in detail. The DNA sequences previously available in GenBank and new sequences produced from some mitochondrial (12S, 16S and COX1) and nuclear (BDNF) molecular markers were used in phylogenetic inference from analyses of Maximum Likelihood and Bayesian Inference to obtain the positioning of these populations in the Amerotyphlops phylogeny. Based on the results presented here, it is proposed that Amerotyphlops illusorium be synonymized with Amerotyphlops brongersmianus and that the populations of the restingas in the north of the state of Rio de Janeiro and the south of Espírito Santo are Amerotyphlops martis, expand significantly the geographic distribution and morphological variation of the species. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação 2025-06-26T00:00:00Z http://hdl.handle.net/11422/29755 Title: Comportamento reprodutivo de centris analis, centris tarsata emegachile microsoma (hymenoptera: apidae, megachilidae) na Amazônia Oriental, Brasil Author(s)/Inventor(s): Pereira, Diego Marinho Advisor: Vivallo, Felipe Abstract: Solitary bees (Hymenoptera: Anthophila) make up the majority of existing bee species. Despite their vast diversity in life histories, little is known about their reproductive biology compared to other aspects of their bionomy. Among solitary bees, those that nest in the soil have had their reproductive behavior studied more thoroughly than those that nest in other substrates, such as in pre-existing cavities. This study aimed to provide unprecedented data on the reproductive behavior of three species of solitary bees: Centris (Hemisiella) tarsata Smith, 1874, C. (Heterocentris) analis (Fabricius, 1804), and Megachile (Ptilosarus) microsoma Cockerell, 1912. The first two species are well known regarding their nesting biology, but no data exists on their reproductive behavior. M. microsoma, on the other hand, has very little information available about its bionomy and nothing in known about its reproductive behavior. The bees were collected in the Amazon biome on Ilha do Maranhão, Maranhão, Brazil, between 2021 and 2023 using trap nests. All species studied were protandrous and females mated only once. Centris analis had the longest copulation, while M. microsoma had the shortest. There are indications of diferente reproductive strategies among Centris species, which may be related to the theories of “Sexual Conflict” and the “Cryptic Female Choice”. In M. microsoma, certainmorphological peculiarities may be linked to the way the bee mates. Publisher: Universidade Federal do Rio de Janeiro Type: Tese 2025-05-25T00:00:00Z