Submitted by (ana.araujo@ufrpe.br) on 2016-08-23T12:27:17Z No. of bitstreams: 1 Miguel Santana de Almeida Neto.pdf: 1157651 bytes, checksum: 9441b1beb74a542d2c1f48a97e3fcee5 (MD5) / Made available in DSpace on 2016-08-23T12:27:18Z (GMT). No. of bitstreams: 1 Miguel Santana de Almeida Neto.pdf: 1157651 bytes, checksum: 9441b1beb74a542d2c1f48a97e3fcee5 (MD5) Previous issue date: 2012-12-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The morphological patterns shown in the species result from the interactions between their phenotype, genotype, and environment through adaptive and evolutionary processes. Thus, this study aims to evaluate the role of phylogeny and feeding in the morphological patterns of the species of Characiformes order, testing the hypothesis that the environmental pressure interferes in the morphological patterns presented by species causing morphological divergence or convergence between them. The site selected for this research was the pond Curralinho, an marginal pond of the Rio São Francisco, located in the state of Pernambuco. In this work we used the twelve species of the Order Characiformes more abundant in the ecosystem evaluated, which were captured in the period from March/2007 to February/2008 Through morphological data and diet analysis, we found that segregation of Characiformes in morphologically distinct groups, reflecting dietary differences. Therefore, morphologically similar species tending to occupy the same trophic guild. The piscivorous Acestrorhynchus britskii, Acestrorhynchus lacustris, Hoplias malabaricus, Serrasalmus brandtii and Pygocentrus piraya showed morphological characteristics that allowed ingest relatively large prey. However, we observed differences in the efficacy of swimming performance of these piscivorous, indicating that the piscivorous that eat whole fish exhibit greater agility swimming performance in order to capture your evasive preys that presented adaptations to avoid and escape the predators. The species Roeboides xenodon and Leporinus reinhardti also preferably used fish in their diets, however, the morphology of these species did not show any adjustments found in majority of the piscivorous. The less swimming speed was evidentiated among the members of the guilds insectivorous and omnivorous, that using food items with lower mobility than fish, like insects, or immobile, such as vegetables. This lower efficiency in swimming performance does not seem to characterize a disadvantage for these species. These appear to preferentially occupy the margin of the water body, which offers greater resource availability for these fish. The relationship between morphology and trophic ecology was confirmed by the Mantel test. This test indicated that the ecological structure of the taxocenosis evaluated probably been shaped by evolutionary adaptations for use of a given resource. These adaptations may be evident when we observe the processes of adaptive convergence and divergence. / Os padrões morfológicos apresentados pelas espécies resultam da interação entre seu fenótipo, genótipo e ambiente, através de processos adaptativos e evolutivos. Dessa forma, este trabalho objetiva avaliar o papel da filogenia e do hábito alimentar nos padrões morfológicos das espécies da Ordem Characiformes, testando a hipótese de que a pressão ambiental interfere nos padrões morfológicos apresentados pelas espécies a ponto de causar divergência ou convergência morfológica entre elas. O local selecionado para esta pesquisa foi a lagoa Curralinho, uma lagoa marginal do Rio São Francisco, localizada no estado de Pernambuco. Neste trabalho foram utilizadas as doze espécies da Ordem Characiformes mais abundantes no ecossistema avaliado, sendo elas capturadas no período de março/2007 a fevereiro/2008. Através de dados morfológicos e análise da dieta, verifica-se que a segregação dos Characiformes em grupos morfologicamente distintos, refletiu de um modo geral, suas diferenças alimentares, com as espécies morfologicamente semelhantes propendendo a ocupar uma mesma categoria trófica. Os piscívoros Acestrorhynchus britskii, Acestrorhynchus lacustres, Hoplias malabaricus, Pygocentrus piraya e Serrasalmus brandtii apresentaram características morfológicas que os permitiram ingerir presas relativamente maiores. No entanto entre esses piscívoros observam-se diferenças na eficiência natatória, indicando que os piscívoros que ingerem peixes inteiros apresentam uma maior agilidade natatória para capturar suas presas evasivas, que se deslocam e apresentam adaptações para fugir de seus predadores. As espécies Roeboides xenodon e Leporinus reinhardti, também utilizaram preferencialmente peixes em suas dietas, no entanto, a morfologia dessas espécies não apresentou as adaptações encontradas na maioria dos piscívoros. A menor velocidade de natação foi evidenciada entre os integrantes das categorias insetívora e onívora, que utilizam itens alimentares com menor mobilidade que os peixes, como os insetos, ou imóveis, como os vegetais. Esta menor eficiência natatória não parece caracterizar uma desvantagem para essas espécies, visto que essas parecem ocupar preferencialmente as margens do corpo d’água, que oferece uma maior disponibilidade de recursos para estes peixes. A relação entre morfologia e ecologia trófica, confirmada pelo teste de Mantel, indica que provavelmente a estruturação ecológica da taxocenose avaliada vem sendo conformada por adaptações evolutivas para utilização de um determinado recurso. Essas adaptações podem ser evidenciadas, quando se observam os processos de convergência e divergência adaptativas.

The deep-sea is the largest habitat on earth, containing over 90 percent of the world’s oceans and home to over 20,000 species. Deep-sea ecosystems are increasingly impacted by human activities including fishing and oil extraction. To understand potential impacts on deep-sea food webs, it is crucial to gather baseline data in these systems. I quantified the trophic interactions of three groups of deep-water animals across a range of trophic levels living in the northern and eastern Gulf of Mexico using stable isotope analysis. First, I propose methods for correcting δ15N values for the presence of nitrogenous metabolic waste products (e.g., urea) in muscle tissue using chemical extractions and/or species-specific mathematical normalizations. Significant differences in δ15N, %N, and C:N values as a result of extractions were observed in eight of ten shark and all three hagfish species. The δ15N values increased, but shifts in %N and C:N values were not unidirectional. Mathematical normalizations for δ15N values were successfully created for four shark and two hagfish species. I then describe the trophic interactions of three consumer assemblages. Carbon isotopic values indicate a heavy reliance on allochthonous nutrient inputs from surface waters. Nitrogen isotopic values reveal somewhat atypical taxa as top predators in the deep sea. Shark, teleost, and invertebrate species across a wide range of body sizes are feeding at a similar trophic level. This apparent lack of size structuring could be the result of a high degree of opportunistic scavenging or perhaps feeding at many trophic levels simultaneously in an oligotrophic system. There was a high degree of isotopic niche overlap among species within each consumer assemblage, perhaps the result of limited nutrient resources in the deep-sea. In general, individuals from the northern sampling stations displayed higher δ13C and δ15N values than those from the eastern sites. With the exception of a few species, there were no strong relationships between body size and isotopic values. The present study is among the first characterizations of the trophic structure of deep-sea organisms in the Gulf of Mexico and establishes system baselines for future studies describing deep-water systems and investigating anthropogenic impacts.

Mesopelagic (open ocean, 200-1000 m depth) fishes are important consumers of zooplankton and are prey of oceanic predators. Some mesopelagic fishes (e.g., myctophids and stomiids) undertake a diel vertical migration where they ascend to the near-surface waters during the night to feed and descend into the depths during the day to avoid predators. Other mesopelagic fishes (e.g., Sternoptyx spp.) do not vertically migrate and remain at deep depths throughout the day. While in the epipelagic zone (surface – 200 m depth), vertically migrating fishes become prey to upper-trophic level predators, such as: tunas and billfishes. Benthic fishes (e.g., macrourids) often vertically migrate as well, ascending into the pelagic zone to feed on pelagic organisms. Fishes of different depths and vertical migration habits likely have a different ecological role in food webs. The relationship between parasites and gut contents provides insights into ecological processes occurring within assemblages, as prey items are often vectors for parasites. This study examined the differences between the prey items present in the gastrointestinal cavity and parasites of 26 mesopelagic fish species in the Gulf of Mexico. Results showed that based on the proportionally dominant prey items per species, six different feeding guilds existed within this assemblage, five based on planktivory: copepodivores, predators of copepods and other zooplankton, predators of copepods and euphausiids, gelatinivores, generalists, crustacean decapodivores, and upper-trophic level predators. Larger fishes preyed on larger prey items and harbored more parasites. Sigmops elongatus exhibited an ontogenetic diet shift at 75 mm standard length, progressing from eating primarily copepods at small sizes to eating primarily euphausiids at large sizes. Compared to similar studies, this study revealed a higher parasitic infestation by trematodes, an endoparasite (parasite within the host) class often restricted to nearshore hosts, in Gulf of Mexico fishes. Helicometrina nimia, the dominant parasite of the gempylid Nealotus tripes, has not previously been recorded in hosts below 200 m depth, suggesting a foodweb pathway that transitions from nearshore to offshore. These data can be used to develop and refine models aimed at understanding ecosystem structure and connectivity.

La distribution d'espèces benthiques intertidales est contrainte par l'océanographie côtière. On connaît moins les effets sur l'écologie des prédateurs. Les côtes sud de l'Afrique sont caractérisées par des contrastes de production primaire et d'assemblages intertidaux dus aux deux courants majeurs qui les longent. Le prédateur apical de ces côtes est un oiseau limicole endémique, l'huîtrier noir africain (Haematopus moquini), qui présente un polymorphisme favorable à la spécialisation alimentaire. Ces travaux ont étudié l'effet des variations spatiales de structure de communautés benthiques sur l'écologie alimentaire de l'huîtrier à l'aide des isotopes stables. Les oiseaux répondent aux fluctuations qualitative et quantitative des communautés de proies à plusieurs échelles. A large échelle ils montrent de forts contrastes entre les côtes ouest et sud-ouest où le régime alimentaire est dominé par les moules, notamment l'espèce invasive Mytilus galloprovincialis et le sud-est où un mélange de moules et patelles est consommé. Localement les individus montrent des différences faibles d'alimentation liées à l'abondance relative des moules et patelles. Cela s'explique par le caractère généraliste de l'espèce et le relâchement de compétition intra-spécifique pour les ressources. La transition alimentaire d'H. moquini vers une consommation quasi-exclusive à l'ouest d'une moule introduite et la multitude de comportements alimentaires ailleurs indiquent un fort potentiel d'adaptation aux modifications de son habitat d'alimentation. En revanche la dégradation des plages par l'Homme augmente la compétition pour l'espace et affecterait aujourd'hui le succès reproducteur de l'espèce. / The distribution of intertidal benthic species is constrained by coastal oceanography. Less is known about the effects on the ecology of predators. Along the southern coasts of Africa the two main currents constraint both the patterns of primary production and the structure of benthic communities. The top predator on these coasts is an endemic shorebird, the African Black Oystercatcher (Haematopus moquini), which exhibits a polymorphism favourable for food specialization. This study investigates the effect of spatial variations in benthic community structure on the feeding ecology of oystercatchers using stable isotopes. Birds respond to changes in quality and quantity of prey at multiple scales. At large scale they show strong contrasts between west and southwest coasts where the diet is dominated by mussels, including the invasive species Mytilus galloprovincialis, and south-east shores where a mixture of mussels and limpets is consumed. Locally individuals show weak dietary differences related to relative abundances of mussels and limpets. This reflects the generalist foraging behaviour of the species and the release of intra-specific competition for resources. The dietary shift of H. moquini on the west coast toward the invasive mussel and the multiplicity of foraging behaviours elsewhere reveal strong capacities to face changes in its foraging habitat. On the other hand the degradation of beaches by humans increases the competition for space and today affects the reproductive success of the species

O lagostim Norte-Americano Procambarus clarkii está dentre as espécies exóticas estabelecidas no Brasil, registrada no estado de São Paulo. Este crustáceo de água doce apresenta grande potencial de invasão (ampla plasticidade ecológica, elevada agressividade, enorme poder de dispersão). Além disso, é portador do oomiceto Aphanomyces astaci, ao qual as espécies de crustáceos nativas do Brasil podem não ser imunes. Inúmeros impactos já foram associados à presença de P. clarkii em várias partes do mundo, desde danos ao ecossistema até impactos sobre a biota nativa. A fim de contribuir com informações relevantes para o desenvolvimento de estratégias de manejo e mitigação de impacto desta espécie no Brasil, esta pesquisa (1) levantou informações sobre a dinâmica populacional e o efeito da sazonalidade na sua abundância, (2) aperfeiçoou e propôs um método padronizado, rápido e acessível para o monitoramento das populações invasoras, (3) testou uma abordagem para controle populacional, (4) verificou a ecologia alimentar e as variações sazonais e intrapopulacionais na dieta, relacionando estes aspectos com o potencial de impacto, (5) analisou a diversidade genética de 9 populações estabelecidas no estado de São Paulo através da utilização de marcadores mitocondriais, (6) sumarizou o panorama legal sobre espécies invasoras, e (7) propoe ações para o manejo de invasão de P. clarkii. Foi definida uma metodologia padronizada para o acompanhamento das populações invasoras de P. clarkii, baseada no método de Schumacher e Eschmeyer para populações fechadas. As análises de dinâmica populacional demonstraram que não há efeito sazonal na abundância da população estudada e que a mesma segue crescendo com taxas consideráveis. Após testar um método de controle populacional baseado na remoção periódica de indivíduos ao longo de um ano, percebeu-se que a abundância populacional aumentou drasticamente e que o controle populacional através de remoção intensiva de indivíduos deve ser mais eficiente que a remoção extensiva. O estudo da dieta evidenciou a voracidade destes lagostins, que se alimentam continuamente de itens diversificados, tanto de origem animal quanto vegetal. Sua alta plasticidade trófica contribui para o alto potencial de estabelecimento em novos ambientes, uma vez que pode utilizar diferentes recursos alimentares dependendo da sua disponibilidade. Esta alta diversidade alimentar também está relacionada com o elevado poder de impacto, uma vez que fontes de diferentes níveis tróficos são utilizadas como recurso alimentar, podendo gerar um desequilíbrio trófico multidirecional, além de ameaçar a abundância e diversidade das espécies consumidas. Nas análises moleculares, foram encontradas apenas 7 haplótipos compartilhados por indivíduos de populações diferentes. Nenhum haplótipo é compartilhado entre populações brasileiras e indivíduos de populações autóctones, embora 3 haplótipos sejam observados entre populações nativas e outros 4 sejam encontrados em algumas populações brasileiras. As diferentes abordagens analíticas aplicadas ao longo deste estudo indicam que P. clarkii está adequadamente adaptado às situações bióticas e abióticas encontradas no Brasil, não havendo nenhuma estação em que os indivíduos encontrem barreiras importantes que pudessem dificultar sua sobrevivência e expansão, de forma que é indiferente a época do ano em que se fará maiores investimentos em manejo das populações invasoras. / Amongst the non-native species currently stablished in Brazil, the North-American freshwater crayfish Procambarus clarkii, is highlighted. This species has notable economic importance worldwide due to its value to aquaculture among aquarists. The occurrence of this species in Brazil seems to be restricted to the State of São Paulo. Procambarus clarkii shows a remarkable potential of invasion as a result of its wide ecological plasticity, elevated aggressiveness and high dispersion capacity. Additionally, it hosts the oomycete Aphanomyces astaci, which might infect and threat native crustaceans. Many impacts were associated to the establishment of this crayfish around the world, from ecosystem disturbances to the harm of native biota. In order to provide relevant information to the development of impact mitigation actions and management strategies related to P. clarkii’s invasion in Brazil, this research (1) evaluated the population dynamics and the effect of seasonality on abundance of one invasive population, (2) adapted and proposed a standardized method to monitor invasive populations which is easily executed and of low budget, (3) tested an approach for population control, (4) verified the trophic ecology of this freshwater crayfish, considering seasonal and intrapopulational variations, relating this aspect to invasive capacity and potential impact, (5) analyzed the genetic variability of 9 populations established in the State of São Paulo through molecular mitochondrial markers, (6) summarized the legal panorama about invasive species, and (7) proposes management actions to deal with P. clarkii invasion. After testing some traditional methods for abundance estimation, in search for the most easily replicated and performed, we defined a standardized methodology to monitor invasive populations of P. clarkii, based in the estimation method of Schumacher and Eschmeyer for closed populations. The population dynamic analysis demonstrated that seasonality does not play a role in abundance and that the population is in continuous growth. The test of population control, based on periodical removal of individuals for a year did not result in a decrease on abundance as we expected. Thus, we believe that intensive animal removal might be more promising than extensive removal. The diet evaluation evidenced the remarkable voracity of this crayfish, which continuously feeds on a variety of items as macrophytes, algae, insects, crustaceans, mollusks, fishes and amphibians. We also found a notable trophic plasticity that must contribute for the great establishment and potential impact offered by this species. The molecular analysis showed 7 haplotypes that are shared among individuals from different populations. No haplotype is shared between native and Brazilian populations however, some native populations share 3 haplotypes and some Brazilian share 4 haplotypes. The variable approaches used in this thesis indicate that P. clarkii is adequately adapted to biotic and abiotic conditions in Brazil and it seems that there is no season in which individuals are under important ecological pressure related to population abundance or food resources, which would difficult their survivorship or range expansion. Thus, according to our data, there is no specific season in which population are subjected to any notable pressure that could be favored for management.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-08-19T14:06:23Z No. of bitstreams: 1 PDF - Rayssa Soares da Silva.pdf: 6993577 bytes, checksum: 4b28a1b3bf1dccef7a141f2729ec2180 (MD5) / Made available in DSpace on 2016-08-19T14:06:23Z (GMT). No. of bitstreams: 1 PDF - Rayssa Soares da Silva.pdf: 6993577 bytes, checksum: 4b28a1b3bf1dccef7a141f2729ec2180 (MD5) Previous issue date: 2016-02-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Seagrass beds are essential habitats for the high biodiversity in coastal environments. They provide nursery, feeding and shelter areas for many organisms. Despite its importance, the seagrass beds are among the most threatened coastal ecosystems on the planet and its influence on fish populations has been little studied in Brazil. The understanding of its influence on the dynamics of fish assemblages associated with these environments and the study of the feeding habits of the species that use them supports the development of new conservation policies of these habitats. Thus, the aim of this study was to compare the composition, structure and feeding ecology of fish assemblages found in vegetated and unvegetated areas on the estuary of the Mamanguape River, Paraiba - Brazil, observing the variations in hydrological conditions between the dry and rainy periods. The values of abundance and biomass were higher in non-vegetated areas, although there was no significant difference in species diversity between study areas. Thus, the environmental stability of unvegetated areas proved to be an important factor in determining the biomass and richness patterns. In addition, it was observed that these areas are used by the species at different stages of their ontogenetic development according to the ratio of optimal foraging and the possibility of refuge from predation. Among the species captured in vegetated and unvegetated áreas on the estuary, the four most representative were selected for analysis of stomach contentes, according to their abundance. Of these, three were considered generalists and showed a high degree of individual specialization, supporting the hypothesis of niche variation proposed by Van Valen. Also, we observed the importance of intraspecific competition and the availability of food items in the intraindividual variation in the diet of the species. / Os bancos de fanerógamas marinhas são habitats essenciais para a elevada biodiversidade em ambientes costeiros, pois constituem áreas de berçário, alimentação e refúgio para diversos organismos. Apesar de sua importância, os bancos de fanerógamas estão entre os ecossistemas costeiros mais ameaçados do planeta e sua influência sobre a ictiofauna foi pouco estudada no Brasil. O entendimento da sua influência sobre a dinâmica das assembleias de peixes associados a estes ambientes e o estudo dos hábitos alimentares das espécies que os utilizam auxilia no desenvolvimento de novas políticas de conservação destes habitats. Deste modo, o objetivo deste estudo foi comparar a composição, estrutura e ecologia alimentar de assembleias de peixes encontradas em áreas vegetadas e não vegetadas do estuário do Rio Mamanguape, Paraíba – Brasil, observando as variações do regime hidrológico entre os períodos seco e chuvoso. Os valores de abundância e de biomassa foram maiores nas áreas não vegetadas, apesar de não haver diferença significativa da diversidade de espécies entre áreas estudadas. Deste modo, a estabilidade ambiental das áreas não vegetadas mostrou -se como fator importante na determinação dos padrões de biomassa e riqueza de espécies. Além disso, foi observado que essas áreas são utilizadas pelas espécies em diferentes fases do seu desenvolvimento ontogenético de acordo com a razão entre o forrageamento ótimo e a possibilidade de refúgio contra a predação. Dentre as espécies capturadas nas áreas vegetadas e não vegetadas do estuário do rio Mamanguape as mais representativas foram selecionadas, de acordo com sua abundância, para análise do conteúdo estomacal. Das quatro espécies, três delas foram consideradas generalistas e apresentaram um alto grau de especialização individual, corroborando com a hipótese da variação de nicho proposta por Van Valen. Além disso, observou-se a importância da competição intraespecífica e da disponibilidade de itens alimentares na variação intraindividual da dieta das espécies.

Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-09-05T18:58:38Z No. of bitstreams: 1 TeseMCS.pdf: 1842426 bytes, checksum: 17216a1313f406228d0e6414935cf518 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-09-20T19:52:43Z (GMT) No. of bitstreams: 1 TeseMCS.pdf: 1842426 bytes, checksum: 17216a1313f406228d0e6414935cf518 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-09-20T19:53:05Z (GMT) No. of bitstreams: 1 TeseMCS.pdf: 1842426 bytes, checksum: 17216a1313f406228d0e6414935cf518 (MD5) / Made available in DSpace on 2017-09-20T19:58:58Z (GMT). No. of bitstreams: 1 TeseMCS.pdf: 1842426 bytes, checksum: 17216a1313f406228d0e6414935cf518 (MD5) Previous issue date: 2017-02-21 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / This thesis describes the bio-ecology of Paralonchurus brasiliensis caught as bycatch for the shrimp trawling fishery targeting Xiphopenaeus kroyeri in Penha, Brazil. Series of 30 minute trawls were made between July/2013 and June/2014 at depths of 10, 20 and 30 meters during which 3040 specimens of P. brasiliensis were collected. All specimens were weighed(g) and measured total length (TL in cm) and from a subsample of 1219 specimens data was obtained for sex-ratio, gonad weight, gonadal maturity, stomach repletion and diet. Paralonchurus brasiliensis is abundant and very frequent, in the bycatch of X. kroyeri, with a ratio of approximately 1: 1 kg between its average biomass and that of the targeted shrimp. CPUE both in number and biomass/trawling did not suffer significant variations and there was no population stratification among the isobaths. In the captures, a large amplitude of Lt (2.7- 23.3cm) was obtained, with a higher number of juveniles and females, regardless of depth. Asymptotic length (L∞) was estimated for males at 33.6 cm, females (30.4 cm) and size of first gonadal maturation estimated for males (16.4cm) and females (15.8 cm). The closed period of shrimp trawling for X. kroyeri only protects the early stages of P. brasiliensis, a continuous yearlong breeding species with peaks between autumn (may) and spring (october). There were significant correlations between abundance versus sand and silt, biomass vs. bottom temperature and silt, as well as RGS-M vs. Silt. The positive allometric growth and relative condition factor close to 1.0 (kn=1), indicated a favorable physiological condition of the specie in the three isobaths. This species showed intense foraging activity, evidenced by the high percentage of stomachs with food (95.73%). The diet of P. brasiliensis is diversified, with greater consumption of polychaetes, crustaceans and ophiuroids, which enables us to classify it as a carnivorous species, predominantly invertivorous. Paralonchurus brasiliensis is a key benthic-demersal species and an opportunistic predator over a wide trophic range intersecting with a vast number of macro-benthic species on marine coastal food webs along the South Brazilian shorelines. Besides the characterization important bioecological aspects of P. brasiliensis, this work contributes to the discussion and understanding of the impact of trawling at the local and world level using the case of P. brasiliensis as a study model. / Esta tese descreve a bioecologia de Paralonchurus brasiliensis capturados na pesca de arrasto de camarão sete-barbas (Xiphopenaeus kroyeri), em Penha, Brasil. Foram realizados arrastos mensais, de 30 min cada, nas isóbatas de 10, 20 e 30m, entre julho/2013 e junho/2014. Dos 3040 exemplares capturados obtiveram-se peso (g) e comprimento total (Lt, em cm) e de 1219 exemplares subamostrados, registraram-se sexo, estádios de maturação e peso (Wt, em g) gonadal, repleção estomacal e a dieta. Paralonchurus brasiliensis é muito frequente, abundante no “bycatch” de X. kroyeri, com proporção aproximada de 1:1kg entre as biomassas anuais das duas espécies. As CPUEs em número e biomassa/arrasto não sofreram variações significativas e não se constatou estratificação populacional entre as isóbatas. Nas capturas obteve-se grande amplitude de Lt (2,7-23,3cm), com maior número de juvenis e fêmeas, independentemente da profundidade. O comprimento assintótico (L∞) foi estimado para machos em 33,6 cm, fêmeas (30,4cm) e o tamanho de primeira maturação gonadal estimados para machos (16,4 cm) e fêmeas (15,8 cm). O defeso de X. kroyeri protege apenas o início do ciclo reprodutivo de P. brasiliensis que se reproduz o ano inteiro, porém, com maiores picos entre outono (maio) e primavera (outubro). Ocorreram correlações significativas entre abundância versus areia e silte, biomassa vs. temperatura de fundo e silte, bem como RGS-M vs. silte. O crescimento alométrico positivo e fator de condição relativo próximo a 1,0 (kn=1), indicaram uma condição fisiológica favorável da espécie nas três isóbatas. Essa espécie demonstrou intensa atividade forrageadora, comprovada pelo elevado percentual de estômagos com alimentos (95,73%). A dieta de P. brasiliensis é diversificada, com maior consumo de poliquetas, crustáceos e ofiuróides, destacando-se como uma espécie carnívora, predominantemente invertívora. Paralonchurus brasiliensis é uma espécie-chave demersal bentônica, predadora, oportunista de amplo espectro trófico e que atua no controle de um grande número de espécies macrobênticas das teias tróficas marinhas costeiras, no sul do Brasil. Além de caracterizar aspectos bioecológicos importantes de P. brasiliensis, este trabalho contribui para a discussão e entendimento do impacto da pesca de arrasto em nível local e mundial utilizando-se o caso de P. brasiliensis como modelo de estudo.

Submitted by FABIANA DA SILVA FRANÇA (fabiana21franca@gmail.com) on 2018-02-23T17:33:04Z No. of bitstreams: 1 Arquivo Total.pdf: 2718770 bytes, checksum: 9378d34888dfcacdd356cf58ac71eaa8 (MD5) / Made available in DSpace on 2018-02-23T17:33:04Z (GMT). No. of bitstreams: 1 Arquivo Total.pdf: 2718770 bytes, checksum: 9378d34888dfcacdd356cf58ac71eaa8 (MD5) Previous issue date: 2017-03-22 / The Rufford Foundation / Understanding the ecological role of species within an ecosystem depends largely on knowledge of its trophic relations. Such relations and the position of species within a foodweb are a central step in understanding the dynamics of the communities and the impacts that each species has on the trophic network compartments. The knowledge on the diet of the South American freshwater stingrays has increased considerably over the last years,but still, little is know about their ecological role. Thereby, the aim of this research is to evaluate the importance of the stingray Potamotrygon magdalenae in the structure of a freshwater food web. The feeding habits and the trophic ecology of this species were evaluated using stomach content analysis in combination with stable isotopes of carbon and nitrogen from samples collected in the middle Magdalena river basin, Colombia, and its ecological importance from topological analyzes of trophic networks. Potamotrygon magdalenae showed a specialized diet, feeding primarily on insects. No significant differences of δ13C and δ15N were observed in the muscle of the species between the hydrological periods of high and low waters. The species isotopic niche was intermediate. In terms of ecological importance, it played an intermediary role in the dispersion of indirect effects through the system, due to its intermediate values of centrality and topological importance. These results provide a starting point for further ecological studies about the South American freshwater stingray species, in order to assess their role in the ecosystem. On the other hand, theycomplement the existing studies of Potamotrygon magdalenae. / Compreender o papel ecológico das espécies no ecossistema depende amplamente do conhecimento de suas relações tróficas. Conhecer tais relações e a posição das espécies em umarede é um passo crucial para entender a dinâmica das comunidades e os impactos quecada espécie tem sobre os demais compartimentos. Oconhecimento sobre adieta das espécies de raias de água doce de América do Sul tem aumentado consideravelmente ao longo dos últimos anos, porém, é muito pouco o que se sabe sobre o papel ecológico das espécies nos seus respectivos ecossistemas. Assim, oobjetivo deste trabalho foi avaliar a importânciaecológica da raia Potamotrygon magdalenae na estrutura da rede trófica de um ecossistema de águas continentais. Foram avaliados os hábitos alimentares e a ecologia trófica da espécie através da análise de conteúdos estomacais e isótopos estáveis de carbono e nitrogênio a partir de amostras coletadas na bacia do médio rio Magdalena, Colômbia; e sua importância ecológica a partir de análises topológicas de redes tróficas. A espécie foi considerada um predador especialista de nível trófico intermediário, com preferência pelos insetos.Não foram observadas diferenças significativas de δ13C e δ15N na espécie entre os períodos hidrológicos de cheia e de águas baixas. O seu nicho isotópico foi intermediário. Em relação à importância ecológica, a espécie desempenhou um papel intermediário na dispersão de efeitos indiretos através do sistema, devido aos seus valores intermediários de centralidade e importância topológica. Estes resultadosconstituem um ponto de partida para novos estudos ecológicos das espécies de raias de água doce da América do Sul, que visem avaliar seu papel nos ecossistemas, e complementam os estudos existentes de Potamotrygon magdalenae.

Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-02-07T10:30:44Z No. of bitstreams: 1 TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5) / Approved for entry into archive by Camila Passos (camilapassos@ufscar.br) on 2017-02-08T12:04:18Z (GMT) No. of bitstreams: 1 TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5) / Approved for entry into archive by Camila Passos (camilapassos@ufscar.br) on 2017-02-08T12:08:38Z (GMT) No. of bitstreams: 1 TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5) / Made available in DSpace on 2017-02-08T12:10:27Z (GMT). No. of bitstreams: 1 TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5) Previous issue date: 2016-03-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / This study examined the ecomorphological pattern ofichthyofauna in two watersheds located on the Upper Paraná River. It was analyzed the ecomorphological variations of species collected from the Beija-Flor stream and Beija-Flor reservoir located in Estação Ecológica de Jataí and Lapa stream located in Área de Proteção Ambiental Corumbataí/Botucatu/Tejubá, to verify interspecific morphological differentiation, the effects oftrophic guilds along the ecomorphological patterns and the effects of water velocity along the ecomorphological standards. Of individuals collected in Estação Ecológica de Jataí, it was selected two Characidium species, on which the ecomorphological variations related to possibility of inter specific morphological differentiation of species of the same genus were analyzed. Considering the common species between the Estação Ecológica de Jataí and the Lapa Stream were observed morphological variables in order to verify the intraspecific morphological differences. Finally these results were related to the meaningof the relation ship between form and function. The main morphological differences found in the individuals of this study were related to the speed of water and feeding habits of the species. The distribution of species in morphological space showed the relation between the ecomorphological attributes and the distribution of species over the water column, where it was possible to characterize the species as demersal, nectobenthicand nektonic species. The relation ship of fish morphology with the water velocity is fundamental. The feeding also contributes with smaller importance in the separation of species in ecomorphological space, but this contribution seems to be because of the presence of these food items is also influenced by the speed of the water. The function of the species in the environmentin which they liveis linked mainly to its trophicniche. / Neste estudo foi analisado o padrão ecomorfológico daictiofauna de duas microbacias localizadas no alto rio Paraná. Foram analisadas as variações ecomorfológicas das espécies coletadas no córrego e represa do Beija-Flor, localizados na Estação Ecológica de Jataí e córrego da Lapa, localizado na Área de Proteção Ambiental Corumbataí/Botucatu/Tejubá, para verificar as diferenças morfológicas interespecíficas, os efeitos das guildas tróficas junto aos padrões ecomorfológicos e os efeitos da velocidade da água junto aos padrões ecomorfológicos. Das espécies coletadas na Estação Ecológica de Jataí, foram selecionadas duas do gênero Characidium, sobre as quais foram analisadas as variações ecomorfológicas relacionadas à possibilidade de existência de diferenciação morfológica interespecífica de espécies pertencentes ao mesmo gênero. Considerando-se as espécies comuns entre a Estação Ecológica de Jataí e o córrego da Lapa, foram observadasas variáveis morfológicas com objetivo deverificar as diferenciações morfológicas intraespecíficas. Por fim, tais resultados foram relacionados ao significado da relação entre forma e função. As principais diferenças morfológicas encontradas nos indivíduos deste estudo foram relacionadas à velocidade da água e ao hábito alimentar das espécies. A distribuição das espécies no espaço morfológico mostrou a relação entre os atributos ecomorfológicos e a distribuição das espécies ao longo da coluna da água, que possibilitou caracterizar as espécies como demersais, nectobentônicas e nectônicas. A relação da morfologia dos peixes com a velocidade da água mostrou-se fundamental. A alimentação aparece com menor importância na separação das espécies no espaço ecomorfológico, mas tal contribuição parece ocorrer devido à presença destes itens alimentares serem influenciados pela velocidade da água. A função das espécies no ambiente em que habitam está ligada, principalmente, ao seu nicho trófico.

Le mercure est un métal présent naturellement dans l’environnement qui a la particularité, sous sa forme organique (le monométhylmercure; MMHg), de se bioaccumuler dans les organismes et de se bioamplifier le long des chaînes alimentaires. Depuis la prise de conscience de la toxicité du MMHg, les travaux se sont multipliés pour comprendre où et comment le MMHg est produit puis incorporé dans les réseaux trophiques marins. Les réponses à ces questions sont primordiales afin d’anticiper le devenir du MMHg dans les espèces commercialisées dans un contexte d’augmentation des émissions de mercure et de changement climatique.Ce travail de thèse s’inscrit dans cette démarche en étudiant les variations spatiales de mercure total contenu dans le muscle de trois espèces de thons: les thons obèses, germons et jaunes, capturés dans le Pacifique sud. Une tendance spatiale similaire a été observée pour les trois espèces avec des concentrations plus élevées dans la zone sud-ouest par rapport à la zone ouest-équatoriale. Ce patron semble être en partie expliqué par des modifications de l’alimentation des espèces en lien avec la structure thermique de la colonne d’eau. La combinaison de mesures des isotopes stables de l’azote et de marqueurs électroniques ont permis de mettre en évidence un approfondissement de l’habitat vertical des thons obèses vers la Nouvelle-Calédonie, leur permettant de se nourrir sur des proies profondes probablement plus concentrées en MMHg. De plus, les profils de MMHg dissous de la partie sud-ouest Pacifique suggèrent une plus forte production de MMHg dans la zone épipélagique augmentant la biodisponibilité du MMHg à la base des chaînes alimentaires pélagiques. / Mercury is a naturally distributed heavy metal which is characterized, under its organic form (monomethylmercury; MMHg), by its bioaccumulation in living organisms and its biomagnifications along food chains. Since the awareness of MMHg neurotoxicity, lots of research works have focused on understanding where and how MMHg is formed and transmited to marine food webs. Those questions are keys in order to anticipate how MMHg, in commercially fish species, will respond in a context of increasing mercury emissions and climate change.This work is part of this approach by studying total mercury spatial variations from muscle tissue of three tuna species: bigeye, albacore and yellowfin tuna, captured within the south Pacific Ocean. Every tuna species demonstrated a consistent and similar spatial trend, with higher total mercury concentrations in the southwest and lower concentrations in the western equatorial Pacific. This spatial trend seems to be in accordance with varying tuna diet linked to the thermal features of the water column. By combining archival tagging data and nitrogen stable isotope analysis, we showed that the deepening of bigeye tuna vertical habitat around New Caledonia might allow them to forage on deeper and MMHg enriched preys. Additionnaly, dissolved MMHg profiles in the southwest Pacific suggest higher methylation processes in the epipelagic zone leading, possibly, to higher MMHg bioavailability for marine food chains.This study highlighted the key role of tuna trophic ecology and particularly foraging depth in their MMHg exposure. Those features have to be considered in future studies evaluating food webs contamination at a spatial or temporal scale.