Gray snapper (Lutjanus griseus) is a common reef fish inhabiting the western Atlantic Ocean. In estuaries of the Southeastern United States, such as Mosquito Lagoon, Florida, oyster reefs, seagrass, and mangrove shorelines are vital nurseries, also known as essential fish habitat (EFH), for juvenile fish. However, EFH in Mosquito Lagoon has declined from historic levels due to human activity. To mitigate these losses, oyster reef and living shoreline restoration projects have occurred to putatively increase the availability of EFH. For gray snapper in Mosquito Lagoon, past studies have assessed local habitat preferences and trophic structure, but the biotic and abiotic factors influencing age and growth rates have not been quantified. To address this knowledge gap, this study aims to quantify the mean age and growth rate of gray snapper in Mosquito Lagoon, and investigate if prey and/or other environmental factors (abiotic/biotic conditions, time, and location/site status) impact size at both lagoon and habitat-specific scales. Results indicate the most common life stage for gray snapper in Mosquito Lagoon are mid-stage juveniles, with living shoreline habitats having a greater proportion of younger juveniles and oyster reef habitats having a greater proportion of older juveniles. Estimated growth rate was 0.43 mm/day. Size was correlated with location/site status and lagged salinity levels, with said environmental factors outperforming stable isotope and gut content variables in model comparisons. Gray snapper mass was also correlated with size in all of the most parsimonious models, suggesting future research should consider including weight-length relationships when investigating the environmental or trophic influences on gray snapper growth. Collectively, this study increases our fundamental understanding of gray snapper population dynamics and provides insight that can be used subsequently to benefit the management of recreational and commercial fisheries in the Southeastern US.

Increases in global temperatures resulting from climate change have raised concern over potential responses of Arctic charr, <i>Salvelinus alpinus</i>, a cold-adapted freshwater/anadromous fish species in the salmonid family. While various aspects of adult Arctic charr ecology are well established, juvenile, and in particular, young-of-the-year (YOY) ecology is less well understood. The study of early life stages is important because of implications for subsequent population dynamics as well as their particular sensitivity to climate change. In this thesis, I aimed to broaden the scope of knowledge on juvenile Arctic charr from Canadian populations with a particular emphasis on YOY, and thermal habitat use through four studies. An intensive study of juvenile Arctic charr from Lake Hazen, Nunavut, demonstrated a preference during the summer for stream environments, particularly those fed by warm upstream ponds. Charr occupying both stream and nearshore lake habitats were found to feed similarly, with chironomids occurring most frequently in diets. Some older stream-dwelling charr preyed on smaller, younger Arctic charr. Preferred stream occupancy is likely mediated by physical barriers created mainly by water velocity, and by distance from the lake, lake-ice dynamics, low water depth, and turbidity. Water velocities and possibly intercohort competition resulted in stream habitat segregation by size, with YOY mainly found in low velocity pools and back eddies adjacent to stream banks, but not in water velocities greater than 0.1m/s. Greatest charr densities in streams were found in small, shallow, slow-flowing side channels, which are highly susceptible to drought. A discriminant function analysis model based on carbon and nitrogen stable isotope values was used to identify offspring of piscivorous large-form and non-piscivorous small-form Arctic charr morphotypes from Lake Hazen, Nunavut. The adult morphotypes were estimated to contribute approximately equally to the YOY population, however, the morphotype offspring were differentially distributed among sampled nursery sites. Unequal distribution corresponds with prerequisites suggested for the evolution of trophic specialists within a single population that experiences assortative mating based on trophic specialization. An assessment of growth rates and otolith-inferred metabolic rates obtained from YOY from 23 populations over a 27˚ latitudinal gradient demonstrated latitudinal variability consistent with countergradient variation where northern populations demonstrated faster growth and higher metabolic rates compared to southern populations. Countergradient variation (CGV) is defined as genetic variation that counteracts the negative influences of the physical environment, minimizing phenotypic variability along a gradient. Otolith-inferred metabolic rates from free-living animals reflect the average daily energy expenditure of the organism, which incorporate the energetic costs of standard metabolic rate (SMR) and other processes such as feeding, locomotion, thermoregulation, reproduction and growth. As such, variations in otolith-inferred metabolic rates may reflect a combined increase in feeding, activity and SMRs in northern populations. Nevertheless, the phenotypic variation in physiological traits observed here demonstrates the significant adaptability of Arctic charr to different thermal regimes with different growing season lengths. Otolith-inferred temperatures and fork lengths at capture from YOY from two proximal fluvial and lacustrine sites in Labrador were used to compare growth and thermal habitat use between habitat types. Otolith-inferred temperatures were not significantly correlated with air temperatures, suggestive of behavioural thermoregulation by YOY at both sites. The majority of YOY from Kogluktokoluk Brook (fluvial) were found using temperatures consistent with laboratory determined preferred temperatures for juvenile Arctic charr, whereas most Tom’s Pond (lacustrine) YOY were found using temperatures ranging between preferred temperatures and optimal temperatures for growth. Otolith-inferred temperatures were only correlated to fork lengths in Tom’s Pond YOY. The lack of correlation in Kogluktokoluk Brook YOY may reflect resource partitioning occurring as a result of territoriality known to occur among stream salmonids. The limited range of temperatures used by fluvial YOY in this study, particularly the lack of cooler temperatures, suggests that fluvial YOY may face barriers to accessing thermal refugia, and as a result may be particularly vulnerable to climate change. Examining the ecology of juvenile Arctic charr from Canadian populations over a number of spatial scales (i.e. latitudinal, regional and local) highlighted the considerable phenotypic plasticity demonstrated by the species. While physiological plasticity observed over the latitudinal gradient reflected the ability for juvenile Arctic charr to utilize different thermal regimes, the regional comparison between habitat types demonstrated that the ability for juvenile Arctic charr to respond to climate change is likely to vary between habitat types. Further, on a local scale, behavioural plasticity was observed, but was found to be influenced by several regulatory factors. The study of the ecology of juvenile Arctic charr in this thesis has highlighted various factors affecting juvenile Arctic charr in Canada: temperature, water velocity, cover, maternal influences, habitat type and ration. The relative contributions of these factors as well as others which were not directly testable in this thesis (e.g. variability in standard metabolic rate, the role of genetic adaptation) are likely to vary with latitude, populations and habitat types. Deciphering the relative roles of these factors will allow better predictions of responses to climate change.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-06-28T12:14:06Z No. of bitstreams: 1 Ewerton Pereira de Oliveira.pdf: 3097383 bytes, checksum: 9fa977ae687b83d00d6da838bc685cb5 (MD5) / Made available in DSpace on 2016-06-28T12:14:06Z (GMT). No. of bitstreams: 1 Ewerton Pereira de Oliveira.pdf: 3097383 bytes, checksum: 9fa977ae687b83d00d6da838bc685cb5 (MD5) Previous issue date: 2015-07-30 / Sagital otoliths were analyzed trying to identify possible relationships among shape groups and environmental, biological and taxonomical variables of fishes. Five hundred otoliths images of different species were obtained. Cluster analysis by Ward's criterion was used in order to form similar otolith groups based on their shapes. This method was applied at two different times: 1) using a matrix of normalized Fourier coefficients, obtained by Fourier Elliptical analysis and Euclidean distance as similarity measure; and 2) using a similarity matrix produced by "TO distance ". Thirteen otolith morphotypes, validated by the silhouette graph, were obtained from both procedures. However, "TO distance" was more efficient, getting more heterogeneous shapes among groups and homogeneous shapes within them. Based on the groups obtained from “TO Distance”, simple correlation analysis was carried out to investigate the relationship among otolith shapes and fish variables. Results showed that the variables related to sulcus acusticus, such as position, depth and shape, were the most significant, getting a percentage of explanation of 100% of the total variability among shape groups. It follows that the results presented here can help to explain how otolith shape varies in function of fish species characteristics. / Otólitos sagita foram analisados buscando identificar possíveis relações entre os grupos de forma do mesmo com as características ambientais, biológicas e taxonômicas de peixes. Quinhentas imagens de otólitos sagita de espécies diferentes foram obtidas sendo estas imagens associadas a um arquivo com informações biológicas, ambientais e taxonômicas dos otólitos. A análise de agrupamento, através do critério de Ward, foi utilizada com o objetivo de formar grupos de otólitos semelhantes quanto a sua forma. Este método foi aplicado em dois momentos distintos, o primeiro utilizando a matriz dos coeficientes de Fourier normalizados, obtidos pela análise de Fourier Elíptica, tendo a distância Euclidiana como indicador de similaridade entre os otólitos e o segundo momento utilizando uma matriz de similaridade produzida pelo “TO distance”, onde foram estabelecidos 13 morfotipos de otólitos quanto a sua forma, estes validados por meio do gráfico da silhueta. Foi possível identificar que o “TO distance” mostrou ser uma medida de similaridade eficiente na separação das imagens, obtendo morfotipos mais heterogêneos entre os grupos e mais homogêneos dentro deles. A análise de correspondência simples mostrou que as variáveis relacionadas aos sulcos acústicos, como posição, profundidade e forma da cauda foram as que mais se destacaram, obtendo um percentual de explicação de 100% da variabilidade total dos dados para as duas dimensões juntas. Os resultados obtidos pelos métodos multivariados facilitaram a interpretação das inter-relações entre os treze grupos e as categorias das variáveis, mostrando como a forma dos otólitos e suas características podem influenciar na vida das espécies.

La sole commune présente au cours de son cycle de vie un changement ontogénétique d’habitat. Les larves sont marines et pélagiques, les juvéniles sont benthiques et vivent dans les nourriceries côtières (lagunes et estuaires) alors que les adultes sont benthiques et marins en zones plus profondes. Les otolithes sont des concrétions minéralisées de carbonate de calcium de l’oreille interne des téléostéens qui ne subissent ni dissolution ni résorption. Ils enregistrent les caractéristiques chimiques et isotopiques des milieux traversés.L’étude de la croissance, de la composition chimique et isotopique des otolithes des soles des nourriceries a confirmé l’existence de deux stocks de soles dans le golfe du Lion, un à l’Est et l’autre à l’Ouest. Les faibles valeurs de &#61540;13C et les fortes valeurs de Ba/Ca des otolithes des soles de l’Est du golfe ont été associées à une forte influence des apports rhodaniens sur la phase de vie larvaire lors des années où le débit du Rhône est normal. En période de crue, une forte influence du fleuve est visible sur les otolithes des soles des nourriceries de l’ensemble du golfe. La croissance des otolithes des juvéniles a été plus élevée lorsque la salinité a été proche de 20 et la température comprise entre 20 et 25°C (période estivale). Les signatures des otolithes de Mauguio et Berre ont présenté des &#61540;13C et Sr/Ca plus faibles que ceux de Thau (influences plus marines sur les proies et les masses d’eau). La spécificité des signatures chimiques et isotopiques des otolithes a permis d’élaborer des profils qui ont été retrouvés chez les populations de soles adultes du golfe, mais aussi vers Marseille et Bandol. Ces soles ont montré une influence du Rhône durant la phase de vie larvaire à 53%. Elles ont également montré une forte similarité avec les profils chimiques de type lagune de Thau (10-56%) et Rhône (19-30%) durant leur vie juvénile. Toutefois, une proportion non négligeable de soles originaires de nourriceries non caractérisées (26-50%) a été observée. / The life cycle of the common sole shows an ontogenetic shift of habitats. The larvae are marine and pelagic, the juveniles are benthic in coastal nurseries (lagoons and estuaries) whereas adults are benthic and live in marine deeper areas. Otoliths are paired calcified structures from the inner ear of teletost fish. They are metabolically inert (neither resorption nor dissolution) and they record, both the age (daily and annual increments) and the chemical and isotopic characteristics of the environment inhabited. Otoliths study provides information on the life history traits of individuals.The study of growth, chemical and isotopic otolith composition of soles from nurseries confirmed the existence of two sole stocks in the Gulf of Lions, one in the Eastern part and the other in the Western part. Low values in &#61540;13C and higher values in Ba/Ca ratio measured in Eastern sole otoliths during the larval life were associated to a high influence of the Rhône River discharge during a normal flow rate periods. Conversely, the one hundred return flood of the 2nd of December 2003 was very high and visible on otoliths from all nurseries in the Gulf of Lions. Juvenile otolith growth was higher in nurseries with low salinity (~20) and temperatures between 20 and 25°C than in more marine nurseries. &#61540;13C and Sr/Ca ratios of otoliths from Berre and Mauguio coastal lagoons were lower than those observed in Thau coastal lagoon (more marine influences on preys and water masses). These specificities of otolith compositions were used for the elaboration of reference profiles, which have been identified in adult populations of the Gulf of Lions, Marseilles and Bandol. Adult have shown an influence of the Rhône River during their larval life at 53%. They have shown a similarity with Thau chemical profile (10-56%) and Rhône profile (19-30%) during their juvenile life. However, 26-50% of fish from uncharacterised nurseries have been observed.

Submitted by Caroline Falcao (caroline.rfalcao@ufpe.br) on 2017-05-22T17:32:45Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese__Aschenbrenner_versão_Definitiva.pdf: 1827049 bytes, checksum: 2b2e0b82d6dc856801226f7368d28b5b (MD5) / Made available in DSpace on 2017-05-22T17:32:45Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese__Aschenbrenner_versão_Definitiva.pdf: 1827049 bytes, checksum: 2b2e0b82d6dc856801226f7368d28b5b (MD5) Previous issue date: 2014-11-25 / O objetivo geral desta tese foi avaliar a conectividade entre ecossistemas costeiros e plataforma continental para a espécie L. alexandrei e estudar a utilização destas áreas em diferentes estágios do ciclo de vida para L. alexandrei e L. jocu na região costeira de PE. Para entender melhor a movimentação entre estas áreas, foram utilizados diferentes métodos combinados: (1) a estrutura etária e de tamanho de L. alexandrei foi determinada para áreas estuarinas (profundidades < 5m) e costeiras (profundidades entre 30 a 60 m) metros da plataforma continental; (2) a assinatura química de otólitos de indivíduos de L. alexandrei capturados em áreas estuarinas e costeiras foi analisada para evidenciar a variação ontogenética na permanência entre os diferentes habitats; (3) a presença em áreas estuarinas e recifes rasos adjacentes a costa em diferentes estágios do ciclo de vida foi detectada e quantificada para L. alexandrei e L. jocu através de censos visuais subaquáticos. Amostras biológicas (otólitos) de L. alexandrei foram coletadas através do acompanhamento de desembarques da pesca de Camboa em regiões estuarinas e pesca de rede e armadilhas em regiões costeiras entre o litoral dos estados de Pernambuco e Alagoas. As coletas foram realizadas durante três anos consecutivos (2010-2012). Otólitos de indivíduos juvenis e adultos foram extraídos, emblocados em resina, seccionados utilizando uma serra metalográfica e analisados inicialmente quanto à sua estrutura etária. Em uma segunda etapa, secções de otólitos foram analisadas com relação à sua assinatura química através de um espectrômetro de massa com ablação a laser. Observações subaquáticas foram realizadas em mangues (duas localidades) e recifes de coral adjacentes (três localidades) (a partir de 90 transectos de 10 x 2 m para cada localidade) durante os meses de novembro a março (2012- 13). Resultados da analise de distribuição etaria mostram que para áreas estuarinas indivíduos apresentaram idades de 0 a 4 anos, enquanto indivíduos coletados em áreas costeiras mais profundas foram mais velhos,entre 3 a 22 anos, indicando que uma mudança entre habitats ocorre aproximadamente entre idades 3 e 4. A frequência do tipo de borda ao longo de um ano utilizado para validar a deposição anual de anéis etários indica que, a formação da banda opaca ocorre no período chuvoso, entre abril e setembro. Dados de crescimento revelam que L. alexandrei possui um crescimento rápido durante os estágios iniciais de vida, atingindo em média 50% de seu tamanho assintótico com idade 2. Parâmetros da curva do modelo de crescimento de von Berlalanffy encontrados para L. alexandrei foram L∞ = 31 cm , k = 0.24, t0 = -1.26, r2 = 0.97. A taxa de mortalidade estimada para indivíduos coletados em áreas costeiras foi Z = 0.22 com sobrevivência de S = 0.78 year-1 . Para a analise microquímica dos otólitos foram medidos seis elementos: 7 Li, 24Mg, 55Mn, 59Co, 88Sr and 137Ba para indivíduos de L. Alexandrei. A analise de material recentemente depositado na borda de otólitos revelou que concentrações na razão elemento:Ca não variaram significativamente ao longo dos três anos testados. Similarmente, com exceção de dois elementos (Ba, Co), a razão elemento:Ca para indivíduos maiores habitando águas costeiras também foi estável, não apresentando diferenças para as diferentes regiões costeiras investigadas. Contrariamente, assinaturas químicas em otólitos de L. alexandrei de tamanhos similares provenientes da região estuarina e áreas costeiras foram distintas. Concentrações de Mn:Ca e Ba:Ca em otólitos foram ambos significativamente maiores para L. alexandrei coletados na região estuarina comparados a peixes coletados na região costeira adjacente, enquanto que para Sr:Ca uma tendência oposta foi observada. Dadas as diferenças pronunciadas na assinatura química entre áreas estuarina e costeiras, transectos de elemento:Ca foram construídos desde a região do núcleo até a margem em otólitos de indivíduos coletados em áreas costeiras para determinar o tempo de movimento (migração ontogenética) entre estuário e áreas costeiras. Concentrações de Mn:Ca e Ba:Ca mostraram um padrão semelhante ao esperado, com maiores concentrações para idades 1 e 2, com diminuição gradual para idades subsequentes. Este padrão sugere que espécimes de L. alexandrei começam a transição para habitats mais costeiros (e.g. menores concentrações de Mn e Ba) após a idade 2. Dados de observações subaquáticas corroboraram estes resultados, revelando que para ambas as espécies, indivíduos menores que 10 cm ocorrem exclusivamente em manguezais. Uma nítida mudança foi observada com um aumento de densidades para indivíduos acima de 10 cm em áreas recifais adjacentes. Para L. alexandrei a ocorrência de pos-assentantes, juvenis e subadultos foi registrada em manguezais enquanto que em recifes adjacentes apenas subadultos e adultos foram registrados. Padrão semelhante foi observado para L. jocu com individuos pos-assentantes, juvenis e subadultos em manguezais e juvenis e subadultos habitando recifes rasos adjacentes. Informações obtidas nesta Tese permitiram uma melhor compreensão dos padrões de crescimento e estrutura etária de L. alexandrei. Resultados sugerem ainda a movimentação ontogenética de L. alexandrei entre habitas costeiros e regiões costeiras mais profundas e permitem uma melhor compreensão da utilização de habitats costeiros em estágios iniciais de vida para as espécies de L. alexandrei e L. jocu. / Current objective of this thesis was to evaluate the connectivity among a shallow nursery area and deeper coastal ecossystems for L. alexandrei, and study utilization of such habitats in different life stages for L. alexandrei and L. jocu in the coastal areas of Pernambuco. In order to better understand movement between these areas, combined methods were applied: (1) initially age structure and size of L. alexandrei individuals were determined between estuarine (depths < 5 m) and deeper coastal areas (depths between 30 and 60 m); (2) otoliths microquimistry of L. alexandrei caught in estuarine and coastal areas were tested to evidence possible movement between these areas; (3) the utilization of mangroves and adjacent shallow reef areas in different life stages were studied through underwater visual census for L. alexandrei and L. jocu. Biological samples (otoliths) of L. alexandrei were collected through fishing landings of corral fisheries in estuarine areas and guillnets and traps for coastal areas between Pernambuco and Alagoas States. Data were collected during three consecutive years (2010- 2012). Otoliths of both juvenile and adult individuals were extracted, embedded in resin, sectioned with a low speed saw, then age structure were determined. In a second step, chemical concentrations of trace elements were analyzed in otolith sections using a laser ablation inductively coupled plasma mass spectrometer. Underwater observations (Total 90 transects of 10 x 2 m for each of the five locations) were performed along November to March (2012-13). Results show that inshore mangroves were comprised of individuals 0 to 4 years (mean: 2) while individuals in deeper reef environments were older (range: 3 to 22; mean: 8), indicating that an ontogenetic shift occurs at approximately age 3 or 4. Edge analysis was used to validate the annual deposition in the otoliths suggesting opaque growth rings were formed in the wet season between April and September. Growth data revealed that L. alexandrei display a faster growth in early life stages, reaching approximately 50% of its asymptotic size at age 2. Age at length data were used to predict growth rates of L. alexandrei using the von Bertalanffy growth model from where the following parameters were calculated: L∞ = 31 cm , k = 0.24, t0 = -1.26, r2 = 0.97. Mortality rates were estimated for coastal habitats, with Z = 0.22 and S = 0.78 year-1 . Concentrations of six trace elements were measure (7 Li, 24Mg, 55Mn, 59Co, 88Sr and 137Ba) in otoliths of L. alexadrei. Element:Ca ratios in the otoliths of juvenile and sub-adult L. alexadrei from estuaries were not significantly different among three consecutive years (2010, 2011 and 2012), suggesting that physicochemical conditions within the nursery investigated was temporally stable. Similarly, apart from two element (Ba, Co), element:Ca ratios for larger L. alexandrei inhabiting coastal waters were also similar. In contrast, otolith chemistry of similar sized L. alexandrei from estuarine and coastal areas was distinctly different (based on recently accreted material). Otolith Mn:Ca and Ba:Ca were both significantly higher for L. alexandrei collected in estuaries compared to fish from adjacent coastal reefs region, while the opposite trend was observed for Sr:Ca. Given the pronounced differences in otolith chemistry between estuarine and coastal areas, element:Ca transects were constructed from the core to margin of the otoliths for adults (age 7+) collected on reefs to determine the timing of movement (ontogenetic migration) from estuarine to coastal areas. Based on observed patterns of decline for both Mn:Ca and Ba:Ca, it appears that L. alexandrei begin to transition to more coastal habitats (i.e., lower element:Ca ratios) after age 2. Underwater observations indicate that for both species, individuals smaller than 10 cm occurred exclusively in mangroves. A distinct shift was observed with higher densities for individuals larger than 10 cm in adjacent shallow reef areas. For L. alexandrei mangroves registered occurrence of (postsettlers, juveniles and subadults) while for shallow reefs only (subadults and adults) were observed. A similar pattern was observed for L. jocu with individuals (postsettlers, juveniles and subadults) in mangroves and (juveniles and subadults) inhabiting shallow reefs. General information provided in this thesis allow a better understanding of size structure and growth pattern for L. alexandrei. Yet results suggest ontogenetic migration for L. alexandrei between shallow coastal and deeper marine habitats as well as a better understanding of habitat utilization in early life stages for L. alexandrei and L. jocu.

Understanding the life history of a species is essential for fully understanding its role within an ecosystem. However, many of the fish species of high ecological value have not been studied due to their less prominent roles in local recreational and commercial fisheries in comparison to other targeted species. This study describes the age and growth patterns of three small tuna species inhabiting South Florida waters: blackfin tuna Thunnus atlanticus, little tunny Euthynnus alletteratus, and skipjack tuna Katsuwonus pelamis. Tuna specimens were collected via donations obtained from various fishing tournaments and charter captains in the areas of the Florida Straits as well as hook-and-line by the Nova Southeastern University Oceanographic Center. Age was described via sagittal otolith deposition patterns. They were removed, dried, sectioned, and rings were counted as well as measured. Validation of the timing of ring deposits was done by marginal increment analysis. Growth parameters were determined by comparison of fish fork length to count measurements. This comparison via the Von Bertalanffy growth equation produced a growth rate for each species: blackfin, L∞ = 95.34 cm, K = 0.28, and t0 = -1.53; little tunny, L∞ = 77.93 cm, K = 0.69, and t0 = -0.69; and skipjack, L∞ = 112.76 cm, K = 0.24, and t0 = -1.70. The curves indicate an average size of an individual of a given species at a certain age. They also give an estimation of a maximum length (L∞) of each species, in addition to specific growth rate, which is indicated by the slope. Parameters of each resulting Von Bertalanffy equation were compared among species. Results were also compared with growth rates currently used in stock assessments by fisheries management organizations, such as the International Commission for the Conservation of Atlantic Tunas (ICCAT).

This thesis is part of the project \"Biodiversity and functioning of a subtropical coastal ecosystem: a contribution to integrated management\" funded by FAPESP - São Paulo Research Foundation - Process 2011/50317-5. Known as Biota Araçá, this project was performed in order to evaluate the diversity and the functionality of a subtropical tidal flat located at the northern coast of São Paulo State, a high diversity area. Our study, based on landmark analysis of fish body shape and otoliths shape, was conducted at the University of São Paulo in collaboration with researchers from the Institut de Ciències del Mar (Consejo Superior de Investigaciones Cientificas, Barcelona, Spain). The thesis was organized in five chapters. In the first one, we present a historical review about the use of morphology as a tool for the Science. Initially this theme was to supply my curiosity about \"how the shape of organisms contributed to the development of biodiversity studies\". The second chapter shows the dependence of the fish assemblages\' morphological structure according to the samplers utilized. For that, nine fishing gears were used to sample the Araçá fish assemblages and we determined which samplers are more useful to represent the total fish morphological variability of the area. Given the heterogeneity and complexity of habitats of Araçá Bay, we supposed that some habitats have major influence in the morphological diversity. Therefore, the aim of the third chapter was to determine how fish diversity techniques reveal the ichthyofauna of the three main habitats of Araçá Bay: intertidal, inner/outer sublittoral, marginal shallow sublittoral (elected as results of the previous chapter). Here we emphasize the importance of abundance data and morpho-functional approaches to understand fish habitat complexities, and consequently, the ecosystem functioning. Thus, we present the more sensible habitats in case of the Araçá\'s environmental degradation. During the development of our study, one question emerged: \"are sagittae landmarks able to describe the fish assemblage biodiversity as well as are fish body shapes?\" To answer this question, in the fourth chapter, the morphological correspondence between fish body shapes and otolith sagittae shapes were assessed. We investigated 43 species using different shape descriptors, attempting to habit, diet, swimming type, and hearing capabilities. Other specific questions were answered: 1- which method: shape indices, wavelets or landmarks, better discriminate species classification and, 2- which one shows the ecological significance of otoliths? In the last chapter, considerations are presented taking in account our initial question \"Are landmarks analysis adequate to identify fish assemblages in a subtropical ecosystem?\" The conclusion is that the method is a useful tool to describe fish body and otolith shapes as well as to define fish assemblages in highly diverse ecosystems. / Esta tese é parte do projeto \"Biodiversidade e funcionamento de um ecossistema subtropical: uma contribuição ao manejo integrado\" financiado pela FAPESP - Fundação de Amparo a Pesquisa do Estado de São Paulo - Processo 2011/ 50317-5. Conhecido como Biota Araçá, este projeto foi desenvolvido com o objetivo de avaliar a diversidade e a funcionalidade de uma planície de maré subtropical localizada no litoral norte do Estado de São Paulo, uma área de alta diversidade. Nosso estudo, baseado na análise de pontos homólogos relacionados à forma dos corpos de peixes e à forma de otólitos, foi conduzido na Universidade de São Paulo com a colaboração de pesquisadores do Institut de Ciències del Mar (Consejo Superior de Investigaciones Cientificas, Barcelona, Espanha). A tese está organizada em cinco capítulos. No primeiro, apresentamos uma revisão histórica sobre o uso da morfologia como ferramenta para a Ciência. Inicialmente, este tema surgiu a partir da nossa curiosidade sobre \"como a forma dos organismos contribuiu para o desenvolvimento dos estudos de biodiversidade\". O segundo capítulo mostra a dependência da estrutura morfológica das assembléias de peixes de acordo com os amostradores utilizados. Para isso, nove artes de pesca foram empregadas para amostrar as assembléias de peixes do Araçá e, foi analisado quais delas foram mais úteis para representar a variabilidade morfológica total das espécies presentes na área. Dada a heterogeneidade e complexidade dos habitats da Baía do Araçá, supusemos que alguns deles apresentariam maior influência na diversidade morfológica da ictiofauna. Assim, o objetivo do terceiro capítulo foi analisar como as técnicas utilizadas na avaliação da diversidade de peixes revelam esta diversidade nos três principais habitats da Baía do Araçá: entremarés, sublitoral interno/externo, sublitoral marginal raso (eleitos a partir dos resultados obtidos no capítulo anterior). Aqui, enfatizamos a importância dos dados de abundância e de abordagens morfofuncionais para entender as complexidades dos habitats para os peixes e, consequentemente, o funcionamento do ecossistema. Ainda aqui, apresentamos os habitats mais sensíveis no caso de uma degradação ambiental do Araçá. Durante o desenvolvimento do estudo, uma questão emergiu: \"pontos homólogos em sagittae são capazes de descrever a biodiversidade da assembléia de peixes, assim como o são as formas corporais?\" Para responder esta questão, no quarto capítulo, avaliamos a correspondência morfológica entre formas corporais de peixes e formas de otólitos sagittae. Nós investigamos 43 espécies utilizando diferentes descritores de forma, com vistas aos hábitos, dieta, tipo de natação e capacidades auditivas. Outras questões específicas foram respondidas: 1- qual método: índices de forma, wavelets ou landmarks, melhor discriminam as espécies para classificação e, 2- qual deles mostra a significância ecológica dos otólitos? No último capítulo, são apresentadas considerações levando em conta nossa pergunta inicial \"A análise de pontos homólogos é adequada para identificar assembléias de peixes em um ecossistema subtropical?\" A conclusão é que o método é uma ferramenta útil para descrever formas de corpos de peixes e otólitos, bem como definir associações de peixes em ecossistemas altamente diversificados.

The mechanisms of mortality during critical life stages of fish are not well-understood and, for many species, it is not clear if the mechanisms are similar for naturally and artificially propagated individuals. For Chinook salmon (Oncorhynchus tshawytscha), natural fish potentially face negative interactions, such as competition, and survival disadvantages, such as smaller size, that may limit survival when in association with hatchery fish. To better understand the mechanisms of mortality for hatchery and natural Chinook salmon during the critical early marine residence stage, I: (1) developed a model to discriminate between hatchery and natural juveniles using otolith structure; (2) directly compared migratory patterns of hatchery and natural juveniles; and (3) determined if there was evidence for selective mortality during early marine residence. I followed two cohorts through space and time by collecting juveniles from May-September in the Columbia River estuary and off the coast in September of 2010 and 2011. I compared attributes of those juveniles when they firstentered marine waters with those of survivors after their first summer at sea. I used a combination of genetic stock identification, otolith chemistry and structure, and physical tags to determine stock of origin, size at and timing of freshwater emigration, marine growth, and production type (hatchery or natural). I focused on the subyearling life history of a federally managed genetic stock group (upper Columbia River summer and fall Chinook salmon, UCR Su/F) because: 1) it is an abundant stock group; 2) subyearlings may be more vulnerable to size-selective mortality than yearlings; and 3) it is currently impossible to assess impacts of hatchery production due to low rates of marking the hatchery fish within this stock group. The classification model included two metrics, the presence or absence of a previously unreported transfer check associated with hatchery rearing and variability in otolith increment width, and predicted production type with a 92% jack-knifed accuracy. Overall, timing of marine entry was similar for hatchery and natural UCR Su/F juveniles, which entered marine waters from May-September with a peak in July and August in both years. Estuarine residence times were brief: 80% of the individuals captured in the estuary had resided in saline waters for < 3 days and mean estuarine residence was significantly greater (7 ± 1.3 d) in 2010 than 2011 (1 ± 0.3 d). The only clear difference was that natural individuals captured in the estuary in 2011 migrated to saline waters earlier (July 13th ± 4 d) than hatchery conspecifics (August 10th ± 6 d). However, the timing of marine entry was similar (July 27th ± 1 d) between hatchery and natural fish collected later in the ocean. This observation could be due to differential survival related to the timing of marine entry. Alternatively, estuarine collections may not have adequately represented the emigrating population due to rapid emigration. I documented clear spatial overlap between production types during early marine residence but no difference in median size at marine entry (100 ± 3.5 mm), size at capture (152 ± 4.0 mm), or marine growth (0.94 ± 0.1 %b l d-1). There were also no significant differences in size at marine entry between estuary and ocean collections, which indicates that size-selective mortality had not occurred. Based on both external tags and the otolith classification model, the mean percentage of natural fish in ocean collections was 17% (± 4.8) greater than in the Columbia River estuary; this finding may indicate that estuarine collections are biased to hatchery fish or, more likely, that natural fish survived at higher rates than hatchery fish. Increased survival of natural fish may be related to greater selection pressure during freshwater rearing and prior experience with predators. This study provides the first direct stock-specific comparison of juvenile migratory behavior in natural and hatchery juvenile Columbia River Chinook salmon during early marine residence. Further research is needed to determine if natural fish consistently survive better than hatchery conspecifics and, if so, determine the specific traits and behaviors that afford a survival advantage. / Graduation date: 2013

Made available in DSpace on 2014-12-17T15:36:35Z (GMT). No. of bitstreams: 1 KellyCAP.pdf: 2804234 bytes, checksum: e14a879efe151d80522174c9403f357e (MD5) Previous issue date: 2009-02-13 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This study investigated factors that influence the group size during the behavior foraging of estuarine dolphin Sotalia guianensis in the coast south of the state Rio Grande do Norte (RN), it also characterized the diet of estuarine dolphins and elaborated an otoliths catalog for aid in the identification of the preys found in the stomach contents. In relation to the group size during behaviour foraging, inside of the Curral Bay, larger frequency of solitary hunt was observed. Factors as tide variation, group composition and seasons didn't present correlation with the number of animals observed during a feeding episode. Capture success for participant was shown significantly larger when the animals hunted alone, what possibly explains the largest frequency of solitary hunt inside of the Curral Bay. About diet, were identified 18 bone fishes species, with predominance of species the families Haemulidae and Sciaenidae and five cephalopods species, including two new species in the diet of Sotalia guianensis in Brazil. Our results indicated that estuarine dolphin in the coast oriental from Rio Grande do Norte (RN) feeds predominantly of fish that form shoal, of habitat estuarino and producing of sounds. The analysis of the images, otoliths of 43 species of coastal fish of the coast of the state of Rio Grande do Norte (RN), aided by the offered descriptions, demonstrated to be an effective methodology for the knowledge of those structures, as well as it represented a form of reducing the subjectivity in the identification of the bone fishes found in stomach content / Esse trabalho investigou os fatores que influenciam o tamanho de grupo durante o comportamento alimentar do boto cinza Sotalia guianensis no litoral sul do estado do Rio Grande do Norte (RN), tamb?m caracterizou a dieta dessa esp?cie na regi?o e elaborou um cat?logo de ot?litos para auxiliar ? identifica??o das presas encontradas nos conte?dos estomacais dos animais analisados. Em rela??o ao tamanho de grupo durante o forrageio, dentro da enseada do curral, foi observado maior freq??ncia de ca?a solit?ria. Fatores como varia??o de mar?, composi??o de grupo e esta??es do ano n?o apresentaram correla??o com o n?mero de animais observados durante um epis?dio de alimenta??o. Contudo, o sucesso de captura por participante mostrou-se significativamente maior quando os animais ca?avam sozinhos, o que possivelmente explica a maior freq??ncia de ca?a solit?ria dentro dessa enseada. Sobre a caracteriza??o da dieta, foram identificadas 18 esp?cies de tele?steos, com predomin?ncia de esp?cies pertencentes ?s fam?lias Haemulidae e Sciaenidae e cinco esp?cies de cefal?podes, incluindo duas esp?cies ainda n?o registradas na dieta de Sotalia guianensis no Brasil. De acordo com as informa??es sobre a dieta, o boto cinza no litoral oriental do Rio Grande do Norte (RN) alimenta-se predominantemente de peixes que formam cardume, de habitat estuarino e produtores de sons. A an?lise das imagens dos ot?litos de 43 esp?cies de peixes costeiros do litoral do estado do Rio Grande do Norte (RN) demonstrou ser uma metodologia eficaz, bem como representou uma forma de diminuir a subjetividade na identifica??o dos tele?steos encontrado em conte?do estomacal

Made available in DSpace on 2014-12-17T15:36:44Z (GMT). No. of bitstreams: 1 MonicaRO_TESE.pdf: 9199361 bytes, checksum: c0ccdbb9830c327846e159e62e15732a (MD5) Previous issue date: 2014-07-03 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The flyingfish, Hirundichthys affinis (G?nther, 1866) (Exocoetidae) and ballyhoo half beak, Hemiramphus brasiliensis (Linnaeus, 1758) (Hemiramphidae) are marine fish species of commercial value, which contribute to artisanal fishery production of Rio Grande do Norte, Brazil. Besides the economic importance, these fish are important from an ecological point of view, being components in pelagic food chain, where they are the preferred prey of larger predators of high commercial value. This study aimed to determine the reproductive strategies of H. affinis and H. brasiliensis and the fishery production of H. affinis in the northern coast of Rio Grande do Norte. The results are presented in the form of six cientific articles and a review paper. The first article presents the morphometric measurements and meristic counts which confirmed the taxonomic status, population structure in length-weight and the gonad development of H. affinis through macroscopic observations of the ovaries and testes. Females of this species were bigger and heavier than males. The second article describes the reproductive tactics, such as, sex ratio, length at first sexual maturity, histological aspects of gonads, fecundity and spawning season, that indicate the reproductive strategy of H. affinis. The third article shows annual changes in the fishery production of H. affinis in Cai?ara do Norte, during the period of 1993 to 2010, emphasizing the relevance of this fish in total fishery production of Rio Grande do Norte, besides registering the fall in production in the years 2008 to 2010. The fourth article describes the population structure, with respect to the length and weight, the length-weight relationship, growth type and sex ratio of Hemiramphus brasiliensis. The fifth article describes the reproductive biology of H. brasiliensis, with details about sex ratio, length at first sexual maturity, fecundity, type of breeding and spawning season. The sixth article deals with the reproductive strategy of H. brasiliensis. The review paper presents the topic of age determination of tropical fish using analysis of otoliths. Both species use the coastal waters of Cai?ara do Norte for reproductive purposes. The flying fish, H. affinis migrates from the oceanic waters to the coastal waters to reproduce, coinciding with the rainy season. H. affinis presents total spawning and a seasonal reproductive strategy. However, H. brasiliensis lives and reproduces in the coastal waters displaying partial spawning and an equilibrium reproductive strategy / O peixe-voador, Hirundichthys affinis (G?nther, 1866) (Exocoetidae) e a agulha preta, Hemiramphus brasiliensis (Linnaeus,1758) (Hemiramphidae) s?o peixes marinhos de valor comercial, que contribuem para a produ??o pesqueira artesanal do Rio Grande do Norte, Brasil. Esses peixes s?o importantes na teia alimentar pel?gica, pois constituem as principais presas preferidas de predadores de alto valor comercial. Este trabalho teve como objetivo determinar as estrat?gias reprodutivas de H. affinis e de H. brasiliensis e a produ??o pesqueira de H. affinis no litoral Norte do Rio Grande do Norte. Os resultados est?o apresentados sob a forma de seis artigos cient?ficos e um artigo de revis?o. O primeiro artigo aborda as medidas morfom?tricas e contagens mer?sticas que confirmaram a taxonomia da esp?cie, a estrutura da popula??o em peso-comprimento e o desenvolvimento das g?nadas de H. affinis, atrav?s de observa??es macrosc?picas dos ov?rios e test?culos. Foi verificado que as f?meas s?o maiores e mais pesados do que os machos. O segundo artigo descreve ?s t?ticas reprodutivas, tais como, propor??o sexual, comprimento da primeira matura??o sexual, aspectos histol?gicos das g?nadas, fecundidade e per?odo de desova, que indicam a estrat?gia reprodutiva de H. affinis. O terceiro artigo mostra a varia??o anual da produ??o de H. affinis em Cai?ara do Norte, durante o per?odo de 1993 a 2010, dando ?nfase a relev?ncia desse peixe na produ??o pesqueira no RN, incluindo o registro da queda na produ??o durante os anos de 2008 a 2010. O quarto artigo apresenta a estrutura populacional, no que tange ao comprimento e peso, a rela??o peso-comprimento, o tipo de crescimento e a propor??o sexual de Hemiramphus brasiliensis. O quinto artigo apresenta a biologia reprodutiva de H. brasiliensis, com detalhes sobre a propor??o sexual, o comprimento da primeira matura??o sexual, a fecundidade, o tipo e o per?odo de desova. O sexto artigo descreve a estrat?gia reprodutiva de H. brasiliensis. O artigo de revis?o aborda o tema de determina??o da idade dos peixes tropicais atrav?s de ot?litos. As duas esp?cies utilizam o litoral de Cai?ara do Norte para fins reprodutivos. H. affinis migra das ?guas oce?nicas para as ?guas costeiras, coincidindo com o per?odo chuvoso. H. affinis apresenta desova total e a estrat?gia reprodutiva do tipo sazonal. Enquanto, H. brasiliensis vive e reproduz nas ?guas costeiras apresentando desova parcelada e uma estrat?gia reprodutiva do tipo de equil?brio