The objective of this dissertation was to examine sailfish (Istiophorus platypterus) and blue marlin (Makaira nigricans) spawning in the Straits of Florida, with a specific focus on 1) the physical and biological characteristics of the spawning environment, and 2) the role of the region within the broader spawning patterns of these two species. In order to accomplish these objectives, two years of monthly ichthyoplankton collections and physical measurements across the Straits of Florida were combined with a finer-scale Lagrangian study. Additionally, a molecular species-identification methodology was developed that was both high-throughput and suitable for use with a broad taxonomic range of species. An initial analysis considered the diversity, assemblages and associated habitat of the larvae of large and medium size pelagic species. In total 36 species and 14,295 individuals were collected during this study, with the highest diversity occurring during the summer, and in the western frontal region of the Florida Current. Sailfish were included in an assemblage with Auxis rochei, A. thazard and Euthynnus alleterattus, all species found in highest abundance during the summer along the western edge of the Straits of Florida. Blue marlin grouped most closely with Thunnus atlanticus, Ruvettus pretiosus and Lampris guttatus, all summer spawners, whose larvae tended to occur further offshore. The primary environmental factors associated with these assemblages were SST (highest summer-early fall), day-length (highest early summer), thermocline depth (shallowest on the Florida side) and fluorescence (highest on the Florida side). A Lagrangian sampling effort was then used to more specifically evaluate the role of frontal zones in sailfish spawning. The results of this sampling indicated that the highest levels of sailfish spawning occurred in a frontal zone associated with the formation of a submesoscale frontal eddy. This spawning resulted in the first-feeding larvae occupying an area rich in prey items. Given the small spatial-scale of the front, and the distribution of the eggs of adult prey items, the results of this work would suggest that sailfish are actively targeting features for spawning that are favorable to the growth and survival of their larvae. Finally the relative importance of the Straits of Florida as a spawning ground was evaluated by calculating the annual egg production of both sailfish and blue marlin within this region. In total it was estimated that 2.1% of western Atlantic sailfish spawning and 1.6% of Atlantic wide blue marlin spawning occurs in the SF. Pop-up satellite tags deployed on sailfish at the start of the spawning season revealed their short residency times in the SF, suggesting that a large (≈10%) transient portion of the sailfish population is responsible for the SF egg production. These results indicate that the SF is a migratory bottleneck for sailfish. In conclusion the results of this study indicate that a hierarchy of physical and biological processes influence the distribution of billfish spawning in space and time. The results provide insights into the movement patterns and life history strategies of these species, and ultimately may aid in the development of the spatially explicit ecosystem based management approaches that are currently being advocated.

On April 20th, 2010, a fire broke out on the Deepwater Horizon (DWH) offshore oil drilling rig on the Macondo prospect located off the coast of the Gulf of Mexico (GOM). This fire and resulting explosions resulted in the sinking of the Deepwater Horizon rig and the largest marine oil spill in history. An estimated 4.9 million (+/- 10%) barrels were released into the Gulf of Mexico over the ensuing 87 days. Many economically important fish species spawn in northern Gulf of Mexico waters; the spawning seasons and pelagic larval phase of many of these species occur within the temporal extent of the DWH oil spill (April through July). Fish eggs and larvae in waters exposed to Macondo oil likely experienced lethal and sublethal physiological effects, leading to potential losses in year class strength depending on the proportion of a population’s larval production encountering oil. Differing spatial distributions of larvae due to different spawning locations and seasons could predict that some species were disproportionately affected by the DWH oil spill. This study aims at quantifying the impact of the spill across numerous taxa, by estimating the proportion of species-, genus-, or family-specific fish larval abundances located within the spatial/temporal domain of the DWH spill until the Macondo well was capped. Estimates and related uncertainties were based on empirical ichthyoplankton data collected over 27 years and on observed and modeled distribution of surface oil slicks and concentrations. In addition, two hypothetical oil spills were simulated on the Western Florida Slope and on the Western interior of the Gulf of Mexico to assess the impact of oil spills to the ichthyoplankton from different offshore locations that would have occurred during the DWH spill period. Ichthyoplankton data collected during annual plankton surveys (and other resource surveys) as part of the Southeast Area Monitoring and Assessment Program – Gulf of Mexico (SEAMAP) during years 1982-2009 were used to describe the composition and distribution of ichthyoplankton in the northern Gulf of Mexico. The SEAMAP larval fish data along with oil surface distributions (both actual and simulated) were used to estimate the proportions of larvae of 115 selected fish taxa that were potentially exposed to DWH oil. Bootstrapping methods were applied to the SEAMAP data to quantify the variability. Proportions of larval fish potentially exposed to oil were calculated for four oil spill scenarios: (1) the DWH spill, (2) an September-December oil spill with the same spatial footprint as the DWH spill but occurring later in the year, (3) a west Florida Slope spill occurring during the months of April-July and centered at 27˚N, 85˚W, and (4) a western GOM spill occurring during the spring and centered at 27˚N, 93.5˚W. Spill scenarios (3) and (4) were modeled using the Connectivity Modeling System (CMS). The CMS is a Lagrangian model which predicts oil droplet distribution and degradation based on oil properties and ocean currents. Significant differences in the proportion of larvae potentially exposed were found in the DWH spill and the three simulations. The proportion of fish larvae exposed to the DWH spill varied between 0% (many species) and 26.8% (Cynoscion nebulosus). The proportion of fish larvae exposed to simulated spills varied between 0% and 78.9% (Bonapartia pedaliota in Western GOM spill). Both the west Florida Slope oil spill and the western GOM spills had a disproportionally greater impact on a larger number of taxa than the DWH spill, even after correcting for their larger spatial extent. For the DWH spill (Scenario 1), the potentially most impacted taxa were Cynoscion nebulosus, Engraulidae, Rachycentron canadum, and Etropus spp. If the DWH spill had occurred in the fall (Scenario 2), the most potentially impacted taxa would have been Leiostomus xanthurus, Elopidae, and Pomatomus saltatrix. For a west Florida slope exposure (Scenario 3), the potentially most impacted taxa would be Holocentridae, Acanthocybium solandri, Coryphaena spp., and Pomacanthidae. For a western GOM spill (Scenario 4), the most potentially impacted taxa would be Bonapartia pedaliota, Thunnus thynnus, Caranx spp., and Holocentridae.. The historical SEAMAP data set combined with the CMS modeling tool provides a powerful planning tool to understand the potential impacts of oil spills in the northern GOM and the relative sensitivity of locations in the Northern GOM to oil spill effects.

University, Diss., 2005--Bremen. / Erscheinungsjahr an der Haupttitelstelle: 2004. Enth. 4 Sonderabdr. aus verschiedenen Zeitschr.

Fish larvae in Australian waters have been studied progressively in the last 2-3 decades including the distribution and abundance of taxa, growth and age, their prey and predators. However, the effect of nutrient limitation on ichthyoplankton is unstudied, particularly in the oligotrophic Australian waters. My study was aimed to examine the effect of natural or anthropogenic nutrients on the abundance, distribution, growth and condition of fish larvae along-shore of the NSW coast (latitude 30-34S), where the East Australian Current departs the NSW coast and generates local upwelling of cool nutrient-rich water. This study shows no significant difference in the total abundance or diversity of either larval fishes amongst the 112 taxa (111 families and 1 order), among regions within or upstream of the upwelling. However in both months, there were distinctive ichthyoplankton assemblages at the family level. The Carangidae, Labridae, Lutjanidae, Microcanthidae, Myctophidae and Scombridae were more abundant in the EAC or oceanic water masses, while the Callionymidae, Clupeidae, Platycephalidae, Sillaginidae and Terapontidae were mostly found in the surface or deep upwelled/uplifted water masses. This pattern is observed in other ichthyoplankton studies and may be a general and useful method to determine mixing of water masses. Larvae of silver trevally (Pseudocaranx dentex) and yellowtail scad (Trachurus novaezelandiae) were generally larger and less abundant in the topographically induced upwelling region, than north of the region in pre-upwelled conditions of the East Australian Current. Both species were mostly at the preflexion stage (less than 4.3 mm in body length and less than 10 days old) in the pre-upwelled conditions, particularly during November, and proportionally more larger and older larvae in the upwelled waters (mostly post-flexion, greater than 4.3 mm in body length and greater than 10 days old). Ages from sagittal otoliths ranged from 2-25 increments (~days) and exhibited linear growth for both species and months over the size range (3-15 mm standard length). The otolith radius-length relationship and the growth rates were similar between species and months, despite the 3-4C difference between months. Overall growth rates of the younger larvae were uniform throughout the entire sampling area (0.5-0.6 mm.d-1), while older larvae grew significantly faster in the upwelled water (0.41 mm.d-1) compared to the non-upwelled conditions (0.34 mm.d-1). Both species tended to be depleted in 13C in the upwelling region (from ???18.5 to ???19.0), consistent with expected ratios from deeper water, whereas the 15N composition tended to increase in Pseudocaranx, but decrease in Trachurus indicating different diets and possibly trophic level. The early life history of both species indicates spawning in pre-upwelled waters, but larval transport into upwelled waters is necessary for faster growth in the post-flexion stage. The assemblage of larval fishes did differ between the upwelled region and a region south of Sydney???s deepwater outfalls, but the difference was ascribed to a latitudinal effect and the EAC. Both larval carangids were enriched in 15N, possibly due to the enriched dissolved organic matter of primary treated sewage. In summary, this study found that the larval fish community can provide a biological means to trace water masses, and estimate their degree of mixing. Remarkably there was no significant effect of upwelling or sewage addition to the abundance or diversity of larval fish, in the nutrient poor waters of the East Australian Current. Larval carangids and pilchards were abundant in late spring off northern NSW, and their early life histories were inferred. Both larval carangid species seem to be spawned in the EAC waters, but as post-flexion larvae grew faster in the upwelled zone. Pre-flexion (less than 10 day old) larval carangids of both genera indicated spawning in the EAC, and the rarer post-flexion (greater than 10 days old) carangids grew faster in the upwelled waters. Here, both genera had stable isotope signatures characteristic of upwelled waters for carbon, but had different nitrogen signatures, indicative of different diets and trophic level status. Larval pilchards actually grew more slowly in the upwelling region, as observed in coastal waters off Japan, and their nursery grounds may be further offshore in the Tasman Front, analogous to their early life history in the Kuroshio Extension.

Fish larvae in Australian waters have been studied progressively in the last 2-3 decades including the distribution and abundance of taxa, growth and age, their prey and predators. However, the effect of nutrient limitation on ichthyoplankton is unstudied, particularly in the oligotrophic Australian waters. My study was aimed to examine the effect of natural or anthropogenic nutrients on the abundance, distribution, growth and condition of fish larvae along-shore of the NSW coast (latitude 30-34S), where the East Australian Current departs the NSW coast and generates local upwelling of cool nutrient-rich water. This study shows no significant difference in the total abundance or diversity of either larval fishes amongst the 112 taxa (111 families and 1 order), among regions within or upstream of the upwelling. However in both months, there were distinctive ichthyoplankton assemblages at the family level. The Carangidae, Labridae, Lutjanidae, Microcanthidae, Myctophidae and Scombridae were more abundant in the EAC or oceanic water masses, while the Callionymidae, Clupeidae, Platycephalidae, Sillaginidae and Terapontidae were mostly found in the surface or deep upwelled/uplifted water masses. This pattern is observed in other ichthyoplankton studies and may be a general and useful method to determine mixing of water masses. Larvae of silver trevally (Pseudocaranx dentex) and yellowtail scad (Trachurus novaezelandiae) were generally larger and less abundant in the topographically induced upwelling region, than north of the region in pre-upwelled conditions of the East Australian Current. Both species were mostly at the preflexion stage (less than 4.3 mm in body length and less than 10 days old) in the pre-upwelled conditions, particularly during November, and proportionally more larger and older larvae in the upwelled waters (mostly post-flexion, greater than 4.3 mm in body length and greater than 10 days old). Ages from sagittal otoliths ranged from 2-25 increments (~days) and exhibited linear growth for both species and months over the size range (3-15 mm standard length). The otolith radius-length relationship and the growth rates were similar between species and months, despite the 3-4C difference between months. Overall growth rates of the younger larvae were uniform throughout the entire sampling area (0.5-0.6 mm.d-1), while older larvae grew significantly faster in the upwelled water (0.41 mm.d-1) compared to the non-upwelled conditions (0.34 mm.d-1). Both species tended to be depleted in 13C in the upwelling region (from ???18.5 to ???19.0), consistent with expected ratios from deeper water, whereas the 15N composition tended to increase in Pseudocaranx, but decrease in Trachurus indicating different diets and possibly trophic level. The early life history of both species indicates spawning in pre-upwelled waters, but larval transport into upwelled waters is necessary for faster growth in the post-flexion stage. The assemblage of larval fishes did differ between the upwelled region and a region south of Sydney???s deepwater outfalls, but the difference was ascribed to a latitudinal effect and the EAC. Both larval carangids were enriched in 15N, possibly due to the enriched dissolved organic matter of primary treated sewage. In summary, this study found that the larval fish community can provide a biological means to trace water masses, and estimate their degree of mixing. Remarkably there was no significant effect of upwelling or sewage addition to the abundance or diversity of larval fish, in the nutrient poor waters of the East Australian Current. Larval carangids and pilchards were abundant in late spring off northern NSW, and their early life histories were inferred. Both larval carangid species seem to be spawned in the EAC waters, but as post-flexion larvae grew faster in the upwelled zone. Pre-flexion (less than 10 day old) larval carangids of both genera indicated spawning in the EAC, and the rarer post-flexion (greater than 10 days old) carangids grew faster in the upwelled waters. Here, both genera had stable isotope signatures characteristic of upwelled waters for carbon, but had different nitrogen signatures, indicative of different diets and trophic level status. Larval pilchards actually grew more slowly in the upwelling region, as observed in coastal waters off Japan, and their nursery grounds may be further offshore in the Tasman Front, analogous to their early life history in the Kuroshio Extension.

Submitted by (edna.saturno@ufrpe.br) on 2017-02-17T16:17:53Z No. of bitstreams: 1 Regis Vinicius Souza Santos.pdf: 929113 bytes, checksum: beba8735782c77bc69b5b5649c207373 (MD5) / Made available in DSpace on 2017-02-17T16:17:53Z (GMT). No. of bitstreams: 1 Regis Vinicius Souza Santos.pdf: 929113 bytes, checksum: beba8735782c77bc69b5b5649c207373 (MD5) Previous issue date: 2012-02-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work was developed in the estuary of the Vaza-Barris River, Sergipe, Brazil, and established nine sampling stations in the hope to ensure maximum representation of the study area. In order to characterize the environment and community ichthyoplankton, we tried to recognize trends and distribution of these organisms to evaluate the role of the estuary as an environment conducive to growth in the early stages of local ichthyofauna. The campaigns were carried out every three months, from April 2010 to January 2011, on two consecutive days during the tide quadrature. For sampling it was used network-cylindrical conical type (500 μm), operated in the flow of ebb tide day and night, with two types of hauls in the surface and one meter deep. The parameters water temperature, dissolved oxygen, salinity, inorganic phosphate, chlorophyll "a", phaeophytin, nitrate and turbidity were obtained in surface of all sampling stations. We collected 38,781 eggs and 3,526 fish larvae. Eggs and larvae were present in all months and all sampling stations. We identified 42 different taxa, distributed in 21 families. The distribution and composition of ichthyoplankton in the estuary of the Vaza-Barris River were strongly influenced by environmental conditions, mainly by the penetration of marine waters through the tidal currents. Some families, like Engraulidae, Gobiidae (Bathygobius soporator, Ctenogobius spp., Gobionellus oceanicus, Gobiosoma nudum and Microgobius meeki), Sciaenidae (Bairdiella ronchus, Cynoscion leiarchus, Macrodon ancylodon, Micropogonias furnieri, Stellifer rastrifer and S. stellifer) and Achiridae (Achirus sp. and Trinectes sp.), occurred throughout the period studied in higher densities, while other rare, as Ostraciidae (Acanthostracion sp.) and Microdesmidae (Microdesmus longipinnis), were recorded for the first time in the region. The fact that families, which are economically and ecologically important, use the estuary during the development of its life cycle, emphasizes the importance of the area in the maintenance of estuarine fish species and the adjacent coastal zone. / O presente trabalho foi desenvolvido no estuário do rio Vaza-Barris, Sergipe, Brasil, sendo estabelecidas nove estações de amostragem na expectativa de garantir a máxima representatividade da área de estudo. Com o objetivo de caracterizar o ambiente e a comunidade ictioplanctônica, procurou-se reconhecer as tendências de distribuição desses organismos e avaliar o papel do estuário como ambiente propício ao desenvolvimento das fases iniciais da ictiofauna local. As campanhas foram realizadas a cada três meses, de abril de 2010 a janeiro de 2011, em dois dias consecutivos durante a maré de quadratura. Para a amostragem foi utilizada rede do tipo cônico-cilíndrica (500 μm), operada nos períodos vazante-diurno e vazante-noturno, em arrastos na superfície e a um metro de profundidade. Os parâmetros temperatura da água, oxigênio dissolvido, salinidade, fosfato inorgânico, clorofila “a”, feofitina, nitrato e turbidez foram obtidos na superfície de todas as estações de amostragem. Foram coletados 38.781 ovos e 3.526 larvas de peixes. Os ovos e as larvas estiveram presentes em todos os meses de amostragem e em todas as estações de coleta . Foram identificados 42 taxa distintos, distribuídos em 21 famílias. A distribuição e composição do ictioplâncton do estuário do rio Vaza-Barris foram fortemente influenciadas pelas condições ambientais, principalmente pela penetração de águas marinhas através das correntes de maré. Algumas famílias, como Engraulidae, Gobiidae (Bathygobius soporator, Ctenogobius spp., Gobionellus oceanicus, Gobiosoma nudum e Microgobius meeki), Sciaenidae (Bairdiella ronchus, Cynoscion leiarchus, Macrodon ancylodon, Micropogonias furnieri, Stellifer rastrifer e S. stellifer) e Achiridae (Achirus sp. e Trinectes sp.), ocorreram durante todo o período estudado em maiores densidades, enquanto outras raras, como Ostraciidae (Acanthostracion sp.) e Microdesmidae (Microdesmus longipinnis), foram registradas pela primeira vez na região. O fato de famílias econômica e ecologicamente importantes utilizarem o estuário durante o desenvolvimento do seu ciclo de vida, enfatiza a importância da área na manutenção da ictiofauna estuarina e da zona costeira adjacente.

Larval fish assemblages were investigated during a three-year multidisciplinary project conducted off the coast of south-western Australia. Larvae were sampled using replicated oblique bongo net tows along a five-station transect extending from inshore (18m depth) to offshore waters (1000m depth). A total of 148 taxa from 93 teleost families were identified. Larvae of Gobiidae, and Blenniidae were abundant inshore, while larvae of pelagic and reef-dwelling families, such as Clupeidae, Engraulidae, Carangidae and Labridae were common in continental shelf waters. Larvae of oceanic families, particularly Myctophidae, Phosichthydae and Gonostomatidae, dominated offshore assemblages. Inshore larval fish assemblages were the most seasonal, in terms of species composition and abundance, with offshore assemblages the least so. Multivariate statistical analyses revealed larval fish assemblages to have a strong temporal and spatial structure. Assemblages were closely correlated to water masses, with species distributions reflecting both cross shelf and along-shore oceanographic processes and events. The strength and position of the warm, southward flowing Leeuwin Current, and of the cool, seasonal, northward flowing Capes Current were shown to drive much of the variability in the marine environment, and thus larval fish assemblages. Many of the distinctions between larval fish assemblages on the continental shelf were attributable to patterns of abundance in clupeiform larvae. While larvae of Engraulis australis and Spratelloides robustus showed clear seasonal and spatial distribution patterns, larvae of Sardinops sagax and Etrumeus teres were found throughout the year, with high interannual variability in abundance. Abundances of larvae from all pelagic clupeiform species were negatively correlated to microzooplankton concentrations. Peaks of abundance of S. sagax and E. teres, in particular, appeared to be better aligned with favourable transport and retention conditions. A detailed comparison of the horizontal and vertical distribution of larval fishes highlighted the influence of contrasting oceanographic conditions between summer and winter on larval fish assemblages. Although most fish larvae were found above the thermocline, depth distributions differed between taxa, and were shown to influence their offshore transport. Neustonic fish larvae showed potential for significant dispersion during summer, as a result of offshore Ekman transport. Mesoscale Leeuwin Current eddies were a feature of the oceanography of the region, and their influence on larval fish assemblages was examined in both an anti-cyclonic eddy (warm-core) and a cyclonic eddy (cold-core). The warm-core eddy contained larval fish assemblages that were distinct from those in the cold-core eddy, with lower larval fish concentrations, especially in the eddy centre. Although the eddies originated near the continental shelf, larval fish assemblages within both eddies were largely oceanic, probably a result of the age of the eddies when they were sampled (about 5 months). Overall, larval fish assemblages showed strong temporal and spatial structure, and were well aligned to water masses in the region. The unique oceanography off south western Australia thus has considerable implications for both larval fish transport, and potential recruitment to regional fisheries.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-09-04T17:30:14Z No. of bitstreams: 1 DelzeniraCosta.pdf: 655988 bytes, checksum: 0d73fad8577433c0e331c0a57009728e (MD5) / Made available in DSpace on 2017-09-04T17:30:14Z (GMT). No. of bitstreams: 1 DelzeniraCosta.pdf: 655988 bytes, checksum: 0d73fad8577433c0e331c0a57009728e (MD5) Previous issue date: 2017-04-04 / This present work was realized out in a profile of the coastal and marine zone of the continental shelf of Maranhão (MCS). This order to describe the existence of structure patterns of fish larvae species in the coastal and marine zone of the MCS, testing the hypothesis that the community structure is related to the environmental conditions of the region. The sampling was performed and distributed at seven collection points (MA1, MA2, MA3, MA4, MA5, MA6 and MA7), throughout nine campaigns in the months of April, August, October and November 2013; January, March, May, July and September 2014. The ichthyoplankton was obtained by horizontal trawls on the surface, using a conical – cylinder plankton net with mesh of 300 μm and 60 cm of mouth diameter. The variables “temperature”, “salinity”, “conductivity”, total dissolved solids – TDS, Water transparency, dissolved oxygen, suspended particulate matter, dissolved nutrients (phosphate and nitrite) were obtained on the water surface at all collection points. The canonical correspondence analysis (CCA) was used to verify the influence of environmental variables on larval abundance and distribution. During the sample period, 4.011 fish larvae were collected, belonging to 23 families, 40 genera and 31 species. The most abundant were Anchovilla lepidentostole, Cynoscion acoupa, Sardinella brasiliensis e Mugil sp. The diversity and richness of species occurred in a way that, at the point MA1 was strongly influenced by many individuals and few species with a high degree of dominance, while in the MA7 was recorded the greatest diversity and richness of species. The more parsimonious CCA model constructed by the forward selection considered the variables water transparency (M), SPM, salinity, TSD and conductivity sufficient to explain the abundance distributions of the species. All together, these variables accounted for 89.6% of the total abundance variation in the larval species. These analyzes demonstrated the existence of two distinct sets of species, namely: i) a set of coastal species with estuarine influence; Ii) a set of marine species with oceanic influence. In general, the formation of fish larvae in the coastal and marine environments of MCS was influenced by the environmental variables of this region. The formation of these sets showed that in the MCS there is a diverse ichthyofauna of commercial and ecological importance. This indicates this area as a zone in need of conservation, in which its characteristics must be preserved. / O presente trabalho foi realizado em um perfil da zona costeira e marinha da Plataforma Continental Maranhense (PCM). O objetivo foi descrever a existência de padrões da estrutura do conjunto de espécies das larvas de peixes na zona costeira e marinha da PCM, testando a hipótese de que a estrutura da comunidade está relacionada às condições ambientais da região. A amostragem foi distribuída entre 7 pontos de coletas (MA1, MA2, MA3, MA4, MA5, MA6 e MA7) durante nove campanhas. Os meses amostrados foram: abril, agosto, outubro e novembro de 2013 e janeiro, março, maio, julho e setembro de 2014. O ictioplâncton foi obtido através de arrastos horizontais na superfície usando rede de plâncton – cônico cilíndrico, com abertura de malha de 300 μm e 30 cm de boca. Os parâmetros temperatura, salinidade, profundidade de transparência, oxigênio dissolvido, material particulado em suspensão (MPS), sólidos totais dissolvidos, condutividade, TDS, pH, fosfato e nitrito foram obtidos na superfície da água em todos os pontos de coleta. Foram utilizadas as análises de correspondência canônica (CCA) para verificar a influência das variáveis ambientais sobre a abundância das larvas. Durante o período amostral foram coletadas 4.011 larvas de peixes, sendo identificadas 43 famílias e 31 espécies. As espécies mais abundantes foram Anchoviella lepidentostolle, Cynoscion acoupa e Mugil sp. A diversidade e riqueza de espécies ocorreram de maneira que, no ponto MA1 foi fortemente influenciado por muitos indivíduos e com poucas espécies com alto grau de dominância, enquanto que no MA7 foi registrada a maior diversidade e riqueza de espécies. O modelo de CCA mais parcimonioso construído pela seleção forward considerou as variáveis transparência da água (m), MPS, salinidade, TDS e condutividade suficientes para explicar as distribuições de abundância das espécies. Consideradas juntas, estas variáveis explicaram 89,6% da variação total das abundâncias no conjunto de espécies de larvas. Estas análises demonstraram a existência de dois conjuntos de espécies distintos, a saber: i) um conjunto de espécies costeiras com influência estuarina; ii) um conjunto de espécies marinhas com influência oceânica. Em geral, a formação da estrutura da comunidade das espécies de larvas de peixes nas zonas costeira e marinha da PCM foi influenciada por variáveis ambientais atuantes nesta área. A formação dos conjuntos das larvas de peixes mostrou que a PCM possui uma diversificada ictiofauna de importância comercial e ecológica. Isto indica esta área como zona de conservação, na qual suas características devem ser preservadas.

Submitted by Valquíria Barbieri (kikibarbi@hotmail.com) on 2018-04-10T19:32:13Z No. of bitstreams: 1 DISS_2014_Gabriela Maria Maimone de Figueiredo.pdf: 941864 bytes, checksum: 484a34af643f773276e576c7baaae016 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2018-04-26T17:22:46Z (GMT) No. of bitstreams: 1 DISS_2014_Gabriela Maria Maimone de Figueiredo.pdf: 941864 bytes, checksum: 484a34af643f773276e576c7baaae016 (MD5) / Made available in DSpace on 2018-04-26T17:22:46Z (GMT). No. of bitstreams: 1 DISS_2014_Gabriela Maria Maimone de Figueiredo.pdf: 941864 bytes, checksum: 484a34af643f773276e576c7baaae016 (MD5) Previous issue date: 2014-03-17 / CNPq / Este estudo teve como objetivo avaliar a distribuição espacial e temporal das assembleias do ictioplâncton do rio Cuiabá e áreas adjacentes, no período de novembro de 2007 a fevereiro de 2008, bem como estudar as relações de densidades dos ovos e larvas com os fatores locais físicos (temperatura, velocidade da água) químicos (fosfato, nitrogênio total, nitrogênio amoniacal), como indicadores da produtividade no ambiente, fatores bióticos (densidades de fitoplâncton e zooplâncton) e com os fatores regionais (nível do rio e pluviosidade), formando condições e locais favoráveis para seu desenvolvimento e sobrevivência nos estágios iniciais de vida dos peixes. As coletas do ictioplâncton foram realizadas em 14 pontos ao longo do rio e áreas adjacentes, com arrastos sub-superficiais de 20 e 40 cm de profundidade, com rede tipo cilindro-cônica de malha 300 μm. Concomitantemente, foram coletadas amostras de fitoplâncton e zooplâncton, bem como realizadas as medidas das variáveis locais e regionais. Após as coletas as amostras foram triadas e identificadas ao menor nível taxonômico possível. Para avaliar as diferenças nas densidades de ovos e larvas nos locais e nos meses de estudo, foi utilizado o teste de ANOVA por medidas repetidas. Foi utilizada uma correlação de Spearman para a análise das densidades de ovos e larvas com as variáveis regionais e com as variáveis locais. Para avaliar as densidades das larvas com as densidades do fitoplâncton e do zooplâncton também foi utilizada a correlação de Spearman, porém, este teste foi feito com as larvas que foram identificadas em nível de gênero e espécie, e posteriormente, com cada espécie de larva de peixe migrador. Para analisar a composição das estruturas das assembleias de larvas através das densidades nos locais foi utilizado o teste de Mantel parcial, entre as distâncias de similaridades, distâncias ambientais e geográficas. Para avaliar a diferença temporal entre os grupos de Characiformes e Siluriformes foi feito o teste de ANOVA por medidas repetidas. Foi realizada uma ordenação direta das densidades das larvas dos migradores nos pontos amostrais. Os resultados espaciais com as densidades de ovos (F1;10= 0,572; p=0,467), e larvas (F1;10= 3,494 ; p=0,091) não foram significativos. Os resultados temporais com as densidades de ovos (F3;30= 0,533; p=0,663) não foram significativos, já para as larvas (F3;30= 4,539; p=0,009) foram significativos, com picos de densidades em novembro e janeiro. Houve correlação significativa entre as densidades das larvas com o nitrogênio total (r=-0,127; p=0,025) e a temperatura da água (r=0,292; p=0,035). O teste de Mantel parcial mostrou que a variação ambiental não foi fator determinante na distribuição da composição taxonômica dos grupos ao longo do rio (r=-0,214; p=0,966) e que as assembleias de larvas apresentam significativa dependência geográfica (r=0,459; p=0,001), quanto mais próximos os pontos geograficamente, mais similares foram as composições taxonômicas. Os resultados taxonômicos mostraram diferença temporal significativa (F3;48= 3,994; p=0,012) entre os grupos dos Siluriformes e Characiformes. / The aim of this study is to assess the spatial and temporal distribution of Ichthyoplankton assemblies of the Cuiabá River and adjacent areas, from November 2007 to February 2008. We also studied the relationships of egg and larvae density with local physical factors (temperature, water velocity) chemical (phosphate, total nitrogen, ammoniac nitrogen) as indicators of productivity in the environment, abiotic factors (densities of phytoplankton and zooplankton), and with regional factors (the river level and rainfall), as they form favorable conditions and locations for their development and survival in the earlier stages of fish life. Ichthyoplankton samples were conducted in 14 points along the river, with subsurface water of 20 and 40 cm deep, with cylinder-type nets of 300 μm. Concomitantly, were collected samples of phytoplankton and zooplankton, and measured the local and regional variables. After the data collecting, the samples were sorted out and identified to the lowest taxonomic level possible. To evaluate differences in densities of eggs and larvae in the localities and in the months of study, ANOVA for repeated measurements was applied. Spearman correlation was used for the analysis of densities of eggs and larvae with regional and local variables. To evaluate larval densities with densities of phytoplankton and zooplankton we also used the Spearman correlation, however, this test was done with larvae that were identified at the level of genus and species, and later, with each species of migrating fish larvae. To analyze the composition of the structure of assemblies of larvae through the densities at the localities, we applied the partial Mantel test, between the distances of similarities, environmental and geographic distances. To evaluate the temporal difference between the groups of Characiformes and Siluriformes, we applied an ANOVA for repeated measurements. A direct ordering of the migratory larvae densities in sampling points was done. The spatial results with egg densities (F1;10= 0,572; p=0,467), and larvae (F1;10= 3,494 ; p=0,091) were not significant. Temporal results with egg densities (F3;30= 0,533; p=0,663) were not significant, however for the larvae (F3;30= 4,539; p=0,009) the results were significant with peaks in November and January. There was a significant correlation between larval densities and total nitrogen (r=-0,127; p=0,025) and the water temperature (r=0,292; p=0,035). The partial Mantel test has shown that the environmental variation was not a determining factor in the distribution of the taxonomic composition of groups along the basin (r=-0,214; p=0,966). The larvae assemblies show significant geographic dependence (r=0,459; p=0,001), the closer the dots geographically, the more similar were the taxonomic compositions. Taxonomic results show significant temporal difference (F3;48= 3,994; p=0,012) between groups of Siluriformes and Characiformes.

Made available in DSpace on 2017-07-10T18:01:56Z (GMT). No. of bitstreams: 1 Luana Wieczorek Fucks.pdf: 1110842 bytes, checksum: 6a60e56633977fc0c1151c11205e9065 (MD5) Previous issue date: 2015-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In order to evaluate the Salminus brasiliensis larval diet in natural environment was analyzed the stomach contents of 200 individuals with standard length ranging between 7.00 to 13.99 millimeters. For that, the food items have been identified, classified and quantified by numeric frequency and occurrence. Were also obtained some morphometric data of both S. brasiliensis larvae and prey captured by them. For the larvae were assessed standard length and size of the mouth, while the prey has been evaluated the maximum height of the body. The material analyzed was collected in the Ilha Grande National Park region in a lotic remaining stretch of the Paraná River, in 18 stations distributed in the main channel, its tributaries and oxbow lakes. The diet of the larvae was predominantly composed of fish larvae, especially of Characiformes and Siluriformes. Cannibalism cases were reported demonstrating that this is a characteristic behavior of the species, and is independent on the availability of other food items. Dorado's larvae show a negative allometric relationship between the proportion size of the upper jaw relative to the standard length, it means, those variables do not grow proportionally throughout the growth. It was observed that there is no selectivity when taking into consideration the height of consumed prey, but their sizes remained within the maximum intake limit, and neither the heights of prey or even the height of the mouth were a factor limiting of intake. / Com o objetivo de avaliar a dieta de larvas de Salminus brasiliensis em ambiente natural, foi analisado o conteúdo estomacal de 200 de indivíduos com comprimento padrão variando entre 7.00 a 13.99 milímetros. Para tanto, os itens alimentares foram identificados e quantificados quanto à frequência numérica e de ocorrência. Foram obtidos alguns dados morfométricos tanto das larvas de S. brasiliensis como das presas ingeridas. Para as larvas foram avaliados o comprimento padrão e tamanho da boca, enquanto que das presas foi avaliado a altura máxima do corpo. O material analisado foi coletado na região do Parque Nacional de Ilha Grande em um trecho do remanescente lótico do rio Paraná, em 18 estações distribuídas na calha principal, seus tributários e lagoas marginais. A dieta das larvas foi composta predominantemente por larvas de peixes, principalmente de Characiformes e Siluriformes. Casos de canibalismo foram registrados demonstrando que este é um comportamento característico da espécie, e independe da disponibilidade de outros itens alimentares. As larvas do dourado apresentam uma relação alométrica negativa entre a proporção do tamanho da maxila superior e o comprimento padrão, isto é, essas variáveis não se desenvolvem proporcionalmente ao longo do crescimento. Pôde-se observar também que não há uma seletividade alimentar quando se leva em consideração a altura das presas consumidas, mas que seus tamanhos mantiveram-se dentro do limite máximo de ingestão, sendo que tanto as alturas das presas e quanto a abertura da boca foram um fator limitante na ingestão.