O objetivo, deste estudo foi investigar o comportamento dos hormônios esteróides 17β-Estradiol (E2), 17α-hidroxiprogesterona (17α-OHP), Testosterona (T) e 11-Ketotestosterona (11-KT), em piracanjuba Brycon orbignyanus de diferentes sexos e idades, na estação reprodutiva, e nas fêmeas submetidas à reprodução induzida. Os animais utilizados no trabalho, eram criados em piscicultura comercial, mantidos em 3 viveiros, separados por lotes de diferentes idades. A coleta dos animais, consistiu de quatro machos e cinco fêmeas (48 meses), identificados através do dimorfismo sexual da espécie, e as demais idades, (12 e 24 meses), coletaram-se, 20 peixes de cada idade, para identificação do sexo através de histologia. Já o experimento de caracterização dos esteróides sexuais na reprodução induzida, foram coletadas cinco fêmeas, selecionadas através das características com: abdome abaulado, papila urogenital, saliente e avermelhada. Após captura, os peixes foram transportados ao laboratório, onde houve coleta de sangue, para quantificação do perfil plasmático de E2, 17α-OHP, T e 11-KT. Posteriormente, os animais foram abatidos e suas gônadas coletadas e fixadas, a fim de que fosse realizada análise histológica para identificação do sexo. Na reprodução induzida, foi coletado sangue em dois momentos: pré-indução (PI) e pós-extrusão (PE). O nível plasmático de E2 nos machos de 12 meses destaca sua ação no processo de proliferação e renovação das espermatogônia observado em machos imaturos. Nas fêmeas o E2 apresentou os maiores níveis (P<0,05) nos animais de 48 meses, confirmando assim, sua principal função na estimulação do processo de vitelogênese, e maturação final do oócito. Quanto aos andrógenos T e 11-KT, os maiores níveis (p<0,05) foram observados nos peixes adultos (48 meses), permitindo afirmar que estes atuam como feedback negativo, do FSH e feedback positivo do LH, fundamental no processo de maturação final e liberação dos gametas, além de regular o comportamento reprodutivo. O resultado da 17α-OHP, sugere que, nas idades estudadas, é indispensável por participar como precursor dos principais esteróides (T, E2 e 11-KT), além da 17α,20β dihydroxy-4-pregnen-3-one (17α,20β-DHP), essencial no estágio final de maturação, e desova na reprodução induzida. / The objective of this study was to investigate the physiological behavior of steroid hormones 17β-Estradiol (E2), 17α-hydroxyprogesterone (17α-OHP), testosterone (T) and 11-Ketotestosterone (11-KT) in Brycon orbignyanus with different sex and ages on the reproductive season and in females submitted to induced reproduction. The animals used in the study were kept in three ponds on a commercial fish farming, separated by lots with different ages. The sampling of animals consisted of the collection of four males and five females (48 months) identified by the sexual dimorphism of the specie. In the other groups (12 and 24 months), 20 fish of each age were collected for identification of sex through histology. In the experiment with characterization of the sexual steroids in the induced reproduction, were collected five females selected through the following characteristics: bulging abdomen and prominent reddish genital papilla. After capture, the fish were transported to the laboratory, where blood was collected for quantification of the plasma profile of E2, 17α-OHP, T and 11-KT Subsequently, the animals were slaughtered and their gonads were collected and fixed for histological analysis. In the induced females, blood was collected at two moments: pre-induction (PI) and post-extrusion (PE). The plasma profile of E2 is fundamental in immature males, highlighting its action in the process of proliferation and renewal of spermatogonia, observed in males of 12 months. In females E2 presented the highest levels (P <0.05) in animals at 48 months, thus confirming its main function in the stimulation of the vitellogenesis process and final oocyte maturation. The highest levels (p <0.05) of T and 11-KT androgens were observed in adult fish (48 months), allowing to affirm that they are acting as FSH negative feedback and LH positive feedback, fundamental in the final maturation and release of the gametes, besides regulating the reproductive behavior of the fish. The results of 17α-OHP suggest this hormon is fundamental in the studied ages because it is a precursor of the main steroids (T, E2 and 11-KT) and 17α, 20β-dihydroxy-4-pregnen-3-one (17α, 20β-DHP), essential in the final stage of maturation and spawning in induced reproduction.

In the past, oceans have strongly influenced atmospheric CO2 levels through organic and inorganic carbon cycling. The inorganic carbon pump relies on the formation of calcium carbonate which releases CO2 into the surface ocean and traps alkalinity in solid form which sinks to deeper ocean layers and sediments. After sinking, calcium carbonate can either then become trapped in the sediments or dissolve increasing the alkalinity of deeper ocean layers. The net effect is of acidifying surface oceans and encouraging release of CO2 to the atmosphere. The present thesis focuses on marine teleost (bony) fish in temperate areas as previously poorly understood but potentially major producers of calcium carbonate in the ocean. Fish in temperate areas may be contributing to carbonate sediment production and as such the inorganic carbon pump. Prior to this thesis only tropical fish have been investigated as major piscine sediment producers. The present thesis describes the composition and morphology of carbonates produced by many different species of temperate fish providing a basis for the understanding the fate of these carbonates in the environments and their potential contribution to sediment production and the inorganic carbon cycle. Characteristics of carbonates produced by fish in the wild were fairly consistent within a species upon examination of carbonates produced by poor cod (Trisopterus minutus) over the course of a year. However, despite the likely consistent and distinct characteristics of fish carbonates, little evidence of them was found in temperate shallow sediments beneath pens of farmed Atlantic salmon (Salmo salar) where there theoretically should be very high production rates. Reduced salinity, often a feature of temperate areas compared to tropical areas, was found to reduce production rates of carbonate from fish compared to higher salinities. However, salinity reductions below the ocean average of 35 psu (practical salinity units) had less impact on production rates than increases above 35 psu. As such it is argued that production rates in temperate environments should still be relatively high considering high fish biomasses in some temperate regions and could still mean fish in temperate areas are an important source of carbonate production and potential sediment production.

Made available in DSpace on 2016-06-02T19:23:02Z (GMT). No. of bitstreams: 1 6679.pdf: 3490417 bytes, checksum: 3ca7a309845b565437be8c6bf262582c (MD5) Previous issue date: 2015-03-05 / Financiadora de Estudos e Projetos / The cardiovascular system plays the fundamental role of supplying the needs of the animals bodily tissues. It both provides the cells with a variety of elements that are essential to their functioning and drains potentially harmful substances, such as metabolites. All of these items are transported through the blood, the propulsion of which is determined by the pressure gradient created by the heart. In addition to promoting circulation, blood pressure is also directly involved in the maintenance of many other physiological processes, making the preservation of this variable at satisfactory levels a prerequisite for an organism s vitality. In light of this need for ideal pressure levels, important mechanisms for blood pressure regulation have been selected during the evolutionary history of vertebrates, and the baroreflex serves as a clear example. These reflexes begin with the monitoring of arterial pressure by baroreceptors, which constantly inform the central nervous system (CNS) of the condition of this variable. The CNS is thus able to change heart rate and systemic vascular resistance in order to normalize arterial pressure when necessary. Though the operation of the baroreflex is already widely understood and though baroreceptors have been located in mammals, these issues are not elucidated and remain quite controversial when it comes to fishes. Thus, the objective of this work was to locate the baroreceptors and their afferences in a teleost, the Colossoma macropomum. To do so, the occurrence and efficiency of the baroreflex were analyzed when this mechanism was induced by pressure imbalancements in intact fish (IN), fish with the first pair of gill arches denervated (G1) and fish with all four pairs of gill arches denervated (G4). The pressure imbalancements were promoted by the administration of the &#945;1-adrenergic agonist phenylephrine and the &#945;1-adrenergic antagonist prazosin, and the baroreflex was assessed using an electrocardiogram that measured heart rate (bpm), relation between pre- and post-pharmacological manipulation heart rates (%), the time required to reach maximum chronotropic baroreflex response, and total heart rate variability (ms). The results revealed that the barostatic reflex was attenuated in the G1 group and nonexistent in G4 group indicating that baroreceptors may be exclusively located in the gill arches of teleosts. / O sistema cardiovascular possui a fundamental função de suprir as necessidades dos tecidos corporais dos animais, fornecendo às células diversos elementos essenciais a seu funcionamento e drenando substâncias potencialmente nocivas (metabólitos). Todos esses fatores são transportados por meio do sangue, o qual tem sua propulsão determinada por um gradiente de pressão criado pelo coração. Além de promover a circulação, a pressão sanguínea também é diretamente relacionada à manutenção de vários outros processos fisiológicos, fazendo com que a preservação dessa variável em níveis satisfatórios seja pré-requisito para a vitalidade de um organismo. Frente a essa necessidade de valores pressóricos ideais, importantes mecanismos reguladores da pressão sanguínea foram selecionados durante a história evolutiva dos vertebrados, e como importante exemplo temos o barorreflexo. Tal reflexo se inicia com o monitoramento da pressão arterial pelos barorreceptores, os quais informam constantemente a condição dessa variável ao sistema nervoso central, o qual é capaz de alterar a frequência cardíaca e a resistência vascular sistêmica de modo a normalizar rapidamente a pressão arterial caso seja necessário. Enquanto o funcionamento do barorreflexo já foi amplamente entendido e os barorreceptores pontualmente localizados em mamíferos, essas questões encontram-se pouco elucidadas e controversas em peixes, originando o objetivo do presente trabalho: localizar os barorreceptores e suas aferências em um teleósteo, o Colossoma macropomum. Para isso, foram analisadas a ocorrência e a eficiência do barorreflexo induzido por desbalanceamentos pressóricos em peixes intactos (IN), com o primeiro par de arcos branquiais desnervados (G1) e com os quatro pares de arcos branquiais desnervados (G4). Os desbalanceamentos pressóricos foram promovidos por meio da administração do agonista &#945;1-adrenérgico fenilefrina e do antagonista &#945;1-adrenérgico prazosina, e o barorreflexo foi avaliado utilizando-se um eletrocardiograma que permitiu a derivação da frequência cardíaca (bpm), da relação entre a frequência cardíaca pré- e pósadministração farmacológica (%), do tempo decorrido até a resposta barorreflexa cronotrópica máxima (s) e da variabilidade total da frequência cardíaca (ms). Os resultados evidenciaram que o reflexo barostático encontrava-se atenuado no grupo G1, ao passo que inexistia no grupo G4 indicando que os barorreceptores localizam-se exclusivamente nos arcos branquiais dos tambaquis e estão distribuídos por todos eles.

O objetivo, deste estudo foi investigar o comportamento dos hormônios esteróides 17β-Estradiol (E2), 17α-hidroxiprogesterona (17α-OHP), Testosterona (T) e 11-Ketotestosterona (11-KT), em piracanjuba Brycon orbignyanus de diferentes sexos e idades, na estação reprodutiva, e nas fêmeas submetidas à reprodução induzida. Os animais utilizados no trabalho, eram criados em piscicultura comercial, mantidos em 3 viveiros, separados por lotes de diferentes idades. A coleta dos animais, consistiu de quatro machos e cinco fêmeas (48 meses), identificados através do dimorfismo sexual da espécie, e as demais idades, (12 e 24 meses), coletaram-se, 20 peixes de cada idade, para identificação do sexo através de histologia. Já o experimento de caracterização dos esteróides sexuais na reprodução induzida, foram coletadas cinco fêmeas, selecionadas através das características com: abdome abaulado, papila urogenital, saliente e avermelhada. Após captura, os peixes foram transportados ao laboratório, onde houve coleta de sangue, para quantificação do perfil plasmático de E2, 17α-OHP, T e 11-KT. Posteriormente, os animais foram abatidos e suas gônadas coletadas e fixadas, a fim de que fosse realizada análise histológica para identificação do sexo. Na reprodução induzida, foi coletado sangue em dois momentos: pré-indução (PI) e pós-extrusão (PE). O nível plasmático de E2 nos machos de 12 meses destaca sua ação no processo de proliferação e renovação das espermatogônia observado em machos imaturos. Nas fêmeas o E2 apresentou os maiores níveis (P<0,05) nos animais de 48 meses, confirmando assim, sua principal função na estimulação do processo de vitelogênese, e maturação final do oócito. Quanto aos andrógenos T e 11-KT, os maiores níveis (p<0,05) foram observados nos peixes adultos (48 meses), permitindo afirmar que estes atuam como feedback negativo, do FSH e feedback positivo do LH, fundamental no processo de maturação final e liberação dos gametas, além de regular o comportamento reprodutivo. O resultado da 17α-OHP, sugere que, nas idades estudadas, é indispensável por participar como precursor dos principais esteróides (T, E2 e 11-KT), além da 17α,20β dihydroxy-4-pregnen-3-one (17α,20β-DHP), essencial no estágio final de maturação, e desova na reprodução induzida. / The objective of this study was to investigate the physiological behavior of steroid hormones 17β-Estradiol (E2), 17α-hydroxyprogesterone (17α-OHP), testosterone (T) and 11-Ketotestosterone (11-KT) in Brycon orbignyanus with different sex and ages on the reproductive season and in females submitted to induced reproduction. The animals used in the study were kept in three ponds on a commercial fish farming, separated by lots with different ages. The sampling of animals consisted of the collection of four males and five females (48 months) identified by the sexual dimorphism of the specie. In the other groups (12 and 24 months), 20 fish of each age were collected for identification of sex through histology. In the experiment with characterization of the sexual steroids in the induced reproduction, were collected five females selected through the following characteristics: bulging abdomen and prominent reddish genital papilla. After capture, the fish were transported to the laboratory, where blood was collected for quantification of the plasma profile of E2, 17α-OHP, T and 11-KT Subsequently, the animals were slaughtered and their gonads were collected and fixed for histological analysis. In the induced females, blood was collected at two moments: pre-induction (PI) and post-extrusion (PE). The plasma profile of E2 is fundamental in immature males, highlighting its action in the process of proliferation and renewal of spermatogonia, observed in males of 12 months. In females E2 presented the highest levels (P <0.05) in animals at 48 months, thus confirming its main function in the stimulation of the vitellogenesis process and final oocyte maturation. The highest levels (p <0.05) of T and 11-KT androgens were observed in adult fish (48 months), allowing to affirm that they are acting as FSH negative feedback and LH positive feedback, fundamental in the final maturation and release of the gametes, besides regulating the reproductive behavior of the fish. The results of 17α-OHP suggest this hormon is fundamental in the studied ages because it is a precursor of the main steroids (T, E2 and 11-KT) and 17α, 20β-dihydroxy-4-pregnen-3-one (17α, 20β-DHP), essential in the final stage of maturation and spawning in induced reproduction.

Foram avaliadas as características hematológicas, mais especificamente a resposta dos elementos de proteção do sangue, de juvenis de pacu, espécie endêmica e neotropical, mantidos em condições adversas e alimentados com dietas contendo colostro bovino liofilizado. Esta primeira secreção láctea, rica fonte de proteínas, moléculas biologicamente ativas e elementos antioxidantes, pode atuar positivamente no sistema de proteção dos animais. No experimento de estresse crônico, juvenis de pacu foram alocados em elevada densidade (50 kg peixe/m3) por 30 dias. No experimento de estresse agudo, os juvenis permaneceram por 15 dias em gaiolas de alimentação, sendo submetidos à baixa concentração de oxigênio (0,75 mg/L). Durante o período experimental, quatro dietas contendo 0, 10, 20 e 30% de colostro bovino liofilizado (CBL) (com 32% de proteína bruta), foram fornecidas duas vezes diariamente (considerando-se quadruplicatas para cada dieta). Antes do início e ao final de cada experimento, analisou-se para cada lote os parâmetros biométricos de biomassa e comprimento para obtenção de análises de desempenho. Oito juvenis para a situação experimental de adensamento, e dez juvenis para a de hipóxia, de cada tratamento, foram anestesiados com benzocaína e amostras de sangue foram coletadas do vaso caudal para análises hematológicas. Foram realizadas análises de eritrograma, leucograma (contagem total e diferencial de leucócitos), hematócrito e calculados os índices hematimétricos. As imunoglobulinas séricas dos juvenis de pacu foram quantificadas através do método de Turvação por Sulfato de Zinco (ZST), que foi padronizado para peixes no presente trabalho. Os juvenis de pacu foram distribuídos em um delineamento experimental inteiramente casualizado no experimento de estresse crônico, e para o de estresse agudo, em blocos, ambos com quatro tratamentos. Os dados foram submetidos à análise de variância, através do procedimento \"General Linear Model\" (PROC GLM) do programa estatístico SAS (1989). Para a avaliação de diferenças entre médias foram efetuados contrastes entre pares de médias utilizando-se o método de Tukey, onde foi considerada a probabilidade de 5% (P<0,05). Não foi observada influência do colostro bovino no desempenho e nas variáveis hematológicas analisadas em ambas situações experimentais, estresse crônico e agudo. Entretanto, para o experimento de estresse agudo, a inclusão de CBL na dieta dos pacus influenciou o número de células granulocíticas especiais, sendo que o grupo que recebeu 0% de CBL apresentou menor número de células que o grupo que recebeu 10% de CBL, assim como o número de monócitos, sendo que o grupo que recebeu 20% de CBL apresentou menor número de células que o grupo que recebeu 30% de CBL na dieta (P<0,05). Embora o colostro bovino não tenha influenciado as variáveis hematológicas analisadas, não houve efeito negativo à esta fonte de proteína heteróloga fornecida aos peixes, uma vez que o desempenho dos animais que receberam o composto na dieta foi semelhante aos animais que receberam dieta sem esta secreção láctea. Considerando os presentes resultados, o colostro bovino liofilizado, uma fonte rica de moléculas bioativas, não contribuiu para a proteção de juvenis de pacu sujeitos à alta densidade de estocagem e baixa oxigenação. / Hematological characteristics were evaluated, specifically the response of blood protection elements of juvenile pacu, endemic and neotropical species, kept under adverse conditions and fed diets containing lyophilized bovine colostrum. This first milk secretion, a rich protein source, biologically active molecules and antioxidant elements, can act positively in the animal protection system. In the chronic stress experiment, juvenile pacu were allocated at high density (50 kg fish/m3) for 30 days. In the acute stress experiment, the juveniles remained for 15 days in feed cages and were submitted to low oxygen concentration (0.75 mg/L). During the experimental period, four diets containing 0, 10, 20 and 30% of lyophilized bovine colostrum (CBL) (with 32% crude protein) were given twice daily (considering quadruplicates for each diet). Before the beginning and the end of each experiment, the biometric parameters of biomass and length were analyzed in each batch for performance analyses. Eight juveniles for the experimental situation of densification and ten juveniles for hypoxia of each treatment were anesthetized with benzocaine and blood samples were collected from the caudal vein for the hematological analysis. Erythrogram, leukogram (total and differential counts of leukocytes), hematocrit and hematimetric indexes were performed. The serum immunoglobulins of the pacu juveniles were quantified by the Zinc Sulfate Turbid (ZST) method, which was standardized for fish in this study. Juveniles pacu were distributed in a completely randomized experimental design for cronic stress experiment, and for acute stress in randomized blocks, both with four treatments. Data were submitted to the \"General Linear Model\"procedure (PROC GLM) of the statistical program SAS (1989). For a mean-to-average assessment, contrasts were performed between pairs of means using the Tukey method, where a probability of 5% (P <0.05) was considered No influence of bovine colostrum was observed on performance and hematological variables analyzed in both experimental situations, chronic and acute stress. However, for the experimental situation of acute stress, the addition of CBL to the diet of pacu influenced the number of special granulocytic cells, and the group that received 0% CBL presented lower number of cells than the group that received 10% CBL, as well as the number of monocytes. The group that received 20% of CBL presented lower number of monocytes than the group that received 30% of CBL in the diet (P <0.05). Although bovine colostrum did not influence the hematological variables analyzed, there was no negative effect on this source of heterologous protein supplied to the fish, since the performance of the animals that received the compound in the diet was similar to the animals that received diet without this milk secretion. Considering theresults, lyophilized bovine colostrum, a rich source of bioactive molecules, does not contribute to the protection of juvenile pacu subjected to high stocking density and low oxygenation.

O fígado é um órgão importante para se analisar como o animal reage a agressões químicas. Um dos métodos utlizado para estudar a regeneração hepática é a hepatectomia parcial (HP). Assim, nosso objetivo foi verificar a influência da hepatectomia de 30% e de 70% sobre a taxa de proliferação das células hepática medida pela incorporação de BrdU na região da incisão e no resto do fígado e a proliferação de ductos biliares e de células epiteliais pré-ductulares biliares (CEPDBs) com o uso de uma combinação de 2 anticorpos específicos para citoqueratinas humanas, AE1/AE3. O pico de proliferação nos animais que sofreram HP de 30% do parênquima hepático deu-se após 1 dia da cirurgia enquanto que os animais que sofreram a HP de 70% o pico ocorreu no terceiro dia após a cirurgia.O índice de proliferação foi semelhante para a região próxima ou distante do corte. Para ambas as HP não houve diferença na regeneração do tecido retirado próximo ou distante da área de incisão. Nas regiões distantes da HP havia maior número de ductos havendo o pico do número de ductos coincidindo com o pico de proliferação celular de ambas as HP. Depois da HP o número de CEPDBs cresce consideravelmente. Os pico de proliferação também ocorreram no primeiro e terceiro dia para a HP de 30% e de 70% respectivamente, sendo mais altos na região distante do corte. Assim, durante a regeneração do fígado de C. gariepinus ocorre hiperplasia compensatória por proliferação de hepatócitos, de ductos biliares e de CEPDBs. A hepatectomia de 30% gerou uma resposta regenerativa intensa e é menos traumática para o animal, a região distante do corte reage mais intensamente que a região próxima do corte no que se refere aos ductos biliares e as CEPDBs. / The liver is an important organ in studies aimed to the verification of animals reactions to chemical injuries. The partial hepatectomy (PH) is one of the methods that are usually employed in hepatic regeneration experiments. Our objectives in this work were to verify the influence of 30% and 70% PH on the hepatic cells proliferation index as it is measured by BrdU nuclear uptake in two regions: close to the hepatic surgery region and in a farther region. The biliary ducts and bile preductular epithelial cells (BPDECs) proliferation was quantified with a combination of two antibodies against the human cytokeratins AE1/AE3. The proliferation index peak in 30% hepatectomy animals occurred one day after the surgery, but in 70% hepatectomy animals the peak was only observed after three days from the surgery. Differences between the proliferation index of the close and the far region were not observed and likewise histological differences were absent. In the regions far from the PH site more biliary ducts were counted than in closer regions, but the peaks were coincident in both regions with the hepatocytes proliferation index. It was also observed that the quantity of BPDECs increased. The peaks occurred in the first and third days for the 30% and 70% PH respectively, and both peaks were higher in the region far from the PH site. We may conclude that C. gariepinus liver regeneration after 30% and 70% PH occurs by means of compensatory hyperplasia by hepatocytes, biliary ducts and BPDECs proliferation. The 30% HP stimulated a strong regenerative response and is less traumatic to the animals. The regions far from the PH site reacts more intensely that the close region concerning the stimulation of biliary ducts and BPDECs proliferation.

Multiple rounds of whole genome duplication (WGD) have played a pivotal role in the expansion, elaboration, and evolutionary diversification of vertebrate genomes. In addition to sharing two rounds of whole genome duplication with all other vertebrates, a teleost-specific genome duplication (TGD) occurred in the stem of the teleost lineage ~350 million years ago (MYA) and is thus a genomic synapomorphy shared by all ~26,000 extant species. The TGD has variously been implicated in accelerated speciation, evolution of morphological complexity, increased rates of molecular evolution, and the evolution of novelty, and therefore is therefore of significant interest for its impact on teleost evolution and also as a model for understanding the evolutionary patterns and processes which accompany WGDs more generally. Investigation of the TGD has contributed extensively to the general understanding of WGDs however, until the present work, a relatively narrow taxonomic sampling of species within a single teleost subdivision, Clupeocephala, have been investigated. This taxonomic bias has left potentially relevant evolutionary changes to the teleost genome in the immediate wake of the TGD obscured. Due to their deeply branching ancestry, species belonging to the two other major teleost subdivisions, Osteoglossomorpha and Elopomorpha, are well positioned for deeper comparative genomic analyses of the TGD and the accompanying phenomenon of diploidization. The focus of the present work has been to develop the first genomic resources specifically for osteoglossomorphs and to investigate the evolutionary patterns and processes which accompanied diploidization prior the deep divergence of the three extant teleost subdivisions. To this end, I have generated de novo genome and transcriptome data from four osteoglossomorph taxa (Pantodon buchholzi, Osteoglossum bicirrhosum, Chitala ornata, and Gnathonemus petersii) and conducted comparative genomic and phylogenetic analysis with other teleosts and pre-TGD vertebrates including the gar Lepisosteus oculeatus. With a focus on Hox and other ANTP class homeobox-containing transcription factor families I provide evidence that speciation of the major teleost subdivisions occurred prior to the termination of the diploidization process following TGD and discuss the evolutionary implications of this model. Beginning with an analysis of the Hox clusters in P. buchholzi I show that divergent resolution of TGD-generated Hox duplicates occurred both at the individual gene level as well as at the level of whole cluster losses. Detailed phylogenetic analyses of the P. buchholzi Hox clusters further revealed that the transition from polyploid alleles to full paralogs during the diploidization process can occur independently in different lineages when speciation rapidly follows WGDs, causing duplicated genes to exhibit a special case of four-way gene homology which I have termed 'tetralogy'. A genome-wide survey of ANTP class homeobox genes in a de novo assembly of the P. buchholzi genome revealed that ancient TGD duplicates of at least 14 subfamilies were preserved uniquely in the P. buchholzi genome and lost from clupeocephalan teleosts. Finally, by comparing the Hox complements in gar and P. buchholzi with three additional osteoglossomorphs I show that the diversity in potential duplicate resolution patterns is also highly variable between osteoglossomorph families. Overall, this work highlights the importance of considering not only the relative timing of gene duplication and speciation in comparative genomic analyses but also their timing relative to diploidization. Going forward, the research community will need to carefully evaluate the effects differences in diploidization rate and pattern, both between lineages and across the genome, have had in influencing the fate of individual gene duplicates as well as upon the macroevolutionary phenomena frequently correlated with WGDs more generally.

Great barracuda Sphyraena barracuda is a large predatory teleost found circumglobally, other than the Eastern Pacific Ocean. The species is commonly caught by both recreational and commercial fishermen as bycatch while targeting other, more economically or recreationally valuable fishes. This species also exhibits an ontogenetic shift in habitat, with juveniles inhabiting mangrove and seagrass habitats, while adults live near offshore reefs and associated structure. This thesis consists of two separate studies of S. barracuda: 1) feeding ecology along an ontogenetic gradient and 2) habitat utilization of as derived through electronic tagging. The first chapter of this thesis describes the feeding ecology of great barracuda in South Florida, with an emphasis on the determination of when the ontogenetic shift in diet occurs between habitats and individual fish sizes. Specimens were collected primarily by seine net and hook-and-line fishing. The specimens were then dissected with the stomach contents examined. This study found that the ontogenetic diet shift in great barracuda begins around the second year, and that juveniles and adults are opportunistic predators with a wide diversity of teleost and crustacean prey items within the selected habitat. The second chapter of this thesis describes the habitat utilization and vertical movements of two great barracuda off of South Florida interpreted from data acquired from pop-up satellite archival tags (PSATs). This study found that large (>100 cm) great barracuda are capable of travelling hundreds of kilometers over a period of days to weeks. The results show that large great barracuda can tolerate temperatures ranging from 17.8° C to 31.3° C, and are capable of diving to depths greater than 175 m. It was also found that there was a significant difference in time spent at depth, with greater depths being inhabited more frequently at night.

O fígado é um órgão importante para se analisar como o animal reage a agressões químicas. Um dos métodos utlizado para estudar a regeneração hepática é a hepatectomia parcial (HP). Assim, nosso objetivo foi verificar a influência da hepatectomia de 30% e de 70% sobre a taxa de proliferação das células hepática medida pela incorporação de BrdU na região da incisão e no resto do fígado e a proliferação de ductos biliares e de células epiteliais pré-ductulares biliares (CEPDBs) com o uso de uma combinação de 2 anticorpos específicos para citoqueratinas humanas, AE1/AE3. O pico de proliferação nos animais que sofreram HP de 30% do parênquima hepático deu-se após 1 dia da cirurgia enquanto que os animais que sofreram a HP de 70% o pico ocorreu no terceiro dia após a cirurgia.O índice de proliferação foi semelhante para a região próxima ou distante do corte. Para ambas as HP não houve diferença na regeneração do tecido retirado próximo ou distante da área de incisão. Nas regiões distantes da HP havia maior número de ductos havendo o pico do número de ductos coincidindo com o pico de proliferação celular de ambas as HP. Depois da HP o número de CEPDBs cresce consideravelmente. Os pico de proliferação também ocorreram no primeiro e terceiro dia para a HP de 30% e de 70% respectivamente, sendo mais altos na região distante do corte. Assim, durante a regeneração do fígado de C. gariepinus ocorre hiperplasia compensatória por proliferação de hepatócitos, de ductos biliares e de CEPDBs. A hepatectomia de 30% gerou uma resposta regenerativa intensa e é menos traumática para o animal, a região distante do corte reage mais intensamente que a região próxima do corte no que se refere aos ductos biliares e as CEPDBs. / The liver is an important organ in studies aimed to the verification of animals reactions to chemical injuries. The partial hepatectomy (PH) is one of the methods that are usually employed in hepatic regeneration experiments. Our objectives in this work were to verify the influence of 30% and 70% PH on the hepatic cells proliferation index as it is measured by BrdU nuclear uptake in two regions: close to the hepatic surgery region and in a farther region. The biliary ducts and bile preductular epithelial cells (BPDECs) proliferation was quantified with a combination of two antibodies against the human cytokeratins AE1/AE3. The proliferation index peak in 30% hepatectomy animals occurred one day after the surgery, but in 70% hepatectomy animals the peak was only observed after three days from the surgery. Differences between the proliferation index of the close and the far region were not observed and likewise histological differences were absent. In the regions far from the PH site more biliary ducts were counted than in closer regions, but the peaks were coincident in both regions with the hepatocytes proliferation index. It was also observed that the quantity of BPDECs increased. The peaks occurred in the first and third days for the 30% and 70% PH respectively, and both peaks were higher in the region far from the PH site. We may conclude that C. gariepinus liver regeneration after 30% and 70% PH occurs by means of compensatory hyperplasia by hepatocytes, biliary ducts and BPDECs proliferation. The 30% HP stimulated a strong regenerative response and is less traumatic to the animals. The regions far from the PH site reacts more intensely that the close region concerning the stimulation of biliary ducts and BPDECs proliferation.

Teleost fishes share a duplication of their entire genomes. We report here on a computational survey of structured non-coding RNAs (ncRNAs) in teleost genomes, focusing on the fate of fish-specific duplicates. As in other metazoan groups, we find evidence of a large number (11,543) of structured RNAs, most of which (~86%) are clade-specific or evolve so fast that their tetrapod homologs cannot be detected. In surprising contrast to protein-coding genes, the fish-specific genome duplication did not lead to a large number of paralogous ncRNAs: only 188 candidates, mostly microRNAs, appear in a larger copy number in teleosts than in tetrapods, suggesting that large-scale gene duplications do not play a major role in the expansion of the vertebrate ncRNA inventory.