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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Variabilidad espacio-temporal de paralarvas de cefalópodos en el mar peruano entre los años 2013 y 2014

Orosco Montenegro, Luz Ximena January 2016 (has links)
Se describe la composición de especies, distribución, abundancia y frecuencia de paralarvas de cefalópodos en el mar peruano. Se determinó un total de 14 familias, 8 géneros, 4 especies en un total de 1109 muestras de zooplancton colectadas con red Hensen a 50 metros de profundidad desde la superficie, proveniente de 8 cruceros de investigación ejecutados durante los años 2013 y 2014; siendo las especies más dominantes Argonauta spp. (41.4%) y Abraliopsis sp. (6.4%); y las familias Ommastrephidae (13%), Octopodidae (9.1%), Gonatidae (3.9%) y Pyroteuthidae (3.7%). Las paralarvas mostraron una distribución espacial y una relación especie-específica con las masas de agua. Las especies de Argonauta spp. estuvieron relacionadas con ASS, ACF y AES/ATS, y el aumento de sus abundancias relacionadas con el aumento de temperatura; la familia Ommastrephidae relacionadas con ASS y ACF, con una distribución oceánica; la familia Octopodidae distribuida solo en el norte-centro dentro de la plataforma continental; la familia Gonatidae asociadas únicamente a ACF; mientras que las familias Onychoteuthidae y Pyroteuthidae no mostraron patrón de distribución ni preferencia por alguna masa de agua específica. Species composition, distribution, abundance and frequency of paralarvae in Peruvian sea are described. It was determined a total of 14 families, 8 genera and 4 species were determined in a total of 1109 zooplankton samples collected with Hensen net to 50m deep from the surface from 8 vessel research carried out during 2013 and 2014; being the most dominant the species Argonauta spp. (41.4%) y Abraliopsis sp. (6.4%); and families Ommastrephidae (13%), Octopodidae (9.1%), Gonatidae (3.9%) and Pyroteuthidae (3.7%). Paralarvae showed a spatial distribution and species-specific relationship with water masses. The species Argonauta spp. was related with SSW, CCS and ESW/TSW, and increased their abundances related to the temperature rise; la family Ommastrephidae related with SSW and CCW, with an oceanic distribution; the family Octopodidae distributed only in the north-center within the continental shelf; the family Gonatidae associated only with CCW; while the families Onychoteuthidae and Pyroteuthidae didn´t show distribution pattern or preference for any specific water masses.
2

CO2-level Dependent Effects of Ocean Acidification on Squid, Doryteuthis pealeii, Early Life History

Zakroff, Casey J. 12 1900 (has links)
Ocean acidification is predicted to lead to global oceanic decreases in pH of up to 0.3 units within the next 100 years. However, those levels are already being reached currently in coastal regions due to natural CO2 variability. Squid are a vital component of the pelagic ecosystem, holding a unique niche as a highly active predatory invertebrate and major prey stock for upper trophic levels. This study examined the effects of a range of ocean acidification regimes on the early life history of a coastal squid species, the Atlantic longfin squid, Doryteuthis pealeii. Eggs were raised in a flow-through ocean acidification system at CO2 levels ranging from ambient (400ppm) to 2200ppm. Time to hatching, hatching efficiency, and hatchling mantle lengths, yolk sac sizes, and statoliths were all examined to elucidate stress effects. Delays in hatching time of at least a day were seen at exposures above 1300ppm in all trials under controlled conditions. Mantle lengths were significantly reduced at exposures above 1300 ppm. Yolk sac sizes varied between CO2 treatments, but no distinct pattern emerged. Statoliths were increasingly porous and malformed as CO2 exposures increased, and were significantly reduced in surface area at exposures above 1300ppm. Doryteuthis pealeii appears to be able to withstand acidosis stress without major effects up to 1300ppm, but is strongly impacted past that threshold. Since yolk consumption did not vary among treatments, it appears that during its early life stages, D. pealeii reallocates its available energy budget away from somatic growth and system development in order to mitigate the stress of acidosis.
3

Oceanografia pesqueira dos estágios iniciais de Loliginidae (Cephalopoda: Myopsida): paralarvas ao longo da plataforma continental entre o Cabo de São Tomé (RJ) e Cananéia (SP) (22º-25ºS) / Fisheries oceanography of the early stages of Loliginidae (cephalopoda: Myopsida): paralarvae along the continental shelf between Cabo de São Tomé (22ºS) and Cananéia (25°S), SE Brazil

Araujo, Carolina Costa de 26 February 2013 (has links)
Lulas da família Loliginidae são recursos pesqueiros em crescente importância no ecossistema marinho da Plataforma Continental Sudeste (PCSE) do Brasil. No entanto, informações sobre a distribuição dos estágios iniciais do seu ciclo de vida são bastante escassas. Com base em amostras de plâncton coletadas por 11 cruzeiros oceanográficos pretéritos do Instituto Oceanográfico da USP entre 1991 e 2005, o presente estudo teve como objetivo a identificação da ocorrência de paralarvas de Loliginidae na região entre o Cabo de São Tomé (RJ) e Cananéia (SP). Das 644 amostras analisadas, foram encontradas 246 paralarvas, sendo 121 identificadas em nível de espécie (Doryteuthis sanpaulensis n=75, Doryteuthis plei n=39, Lolliguncula brevis n=6 e Pickfordiateuthis pulchella, n=1). Os padrões de distribuição da Família em relação aos processos oceanográficos foram identificados a partir de mapas de distribuição horizontal e vertical de abundância, temperatura e salinidade. Modelos Lineares Generalizados (GLMs) foram utilizados para detectar os fatores que explicariam a ocorrência e a abundância de Loliginidae, os quais indicaram que a profundidade e a temperatura superficial do mar são as principais variáveis explanatórias. Uma Análise de Redundância (RDA) evidenciou os principais padrões de distribuição observados das três principais espécies de Loliginidae em relação às variáveis oceanográficas. D. sanpaulensis predominou na região norte da área de estudo, associada a águas frias e a eventos de ressurgência. D. plei ocorreu principalmente na região sul da área e em águas mais quentes. L. brevis foi encontrada apenas na região estuarina de Santos, em águas rasas e menos salinas. Os resultados obtidos representam uma contribuição relevante ao conhecimento sobre a Oceanografia Pesqueira das lulas no ecossistema marinho regional. / Loliginid squids are fisheries resources of increasing importance in the shelf ecosystem of Southeastern Brazil. Therefore, information about distribution of the early stages of their life cycle is scarce. Based on plankton samples collected by eleven historical oceanographic surveys cruises of the University of São Paulo\'s Oceanographic Institute between 1991 and 2005, the present study aimed identification of the occurrence of Loliginidae paralarvae in the region between Cabo de São Tomé (22ºS) and Cananéia (25ºS). From 664 samples analyzed, 246 paralarvae were found, being 121 identified to the species level, (Doryteuthis sanpaulensis n=75, Doryteuthis plei n=39,, Lolliguncula brevis n=6 and Pickfordiateuthis pulchella, n=1). The distributional patterns of Loliginidae in relation to oceanographic processes were identified by using horizontal and vertical maps of abundance, temperature and salinity. Generalized Linear Models (GLMs) were used to detect the factors that explain Loliginidae occurrence and abundance, which indicated that depth and sea surface temperature, were major explanatory variables. A Redundancy Analyses (RDA) showed the main observed distribution patterns of the three species of Loliginidae in relation to oceanographic variables. D. sanpaulensis occurred in the northern region associated to cold waters and upwelling events. D. plei occurred mainly in the southern region of the study area and in warmer waters.L. brevis was found in the estuarine region of Santos, in shallow and low salinity waters. The obtained results represent a relevant contribution to squids Fisheries Oceanography in the regional marine ecosystem.
4

Oceanografia pesqueira dos estágios iniciais de Loliginidae (Cephalopoda: Myopsida): paralarvas ao longo da plataforma continental entre o Cabo de São Tomé (RJ) e Cananéia (SP) (22º-25ºS) / Fisheries oceanography of the early stages of Loliginidae (cephalopoda: Myopsida): paralarvae along the continental shelf between Cabo de São Tomé (22ºS) and Cananéia (25°S), SE Brazil

Carolina Costa de Araujo 26 February 2013 (has links)
Lulas da família Loliginidae são recursos pesqueiros em crescente importância no ecossistema marinho da Plataforma Continental Sudeste (PCSE) do Brasil. No entanto, informações sobre a distribuição dos estágios iniciais do seu ciclo de vida são bastante escassas. Com base em amostras de plâncton coletadas por 11 cruzeiros oceanográficos pretéritos do Instituto Oceanográfico da USP entre 1991 e 2005, o presente estudo teve como objetivo a identificação da ocorrência de paralarvas de Loliginidae na região entre o Cabo de São Tomé (RJ) e Cananéia (SP). Das 644 amostras analisadas, foram encontradas 246 paralarvas, sendo 121 identificadas em nível de espécie (Doryteuthis sanpaulensis n=75, Doryteuthis plei n=39, Lolliguncula brevis n=6 e Pickfordiateuthis pulchella, n=1). Os padrões de distribuição da Família em relação aos processos oceanográficos foram identificados a partir de mapas de distribuição horizontal e vertical de abundância, temperatura e salinidade. Modelos Lineares Generalizados (GLMs) foram utilizados para detectar os fatores que explicariam a ocorrência e a abundância de Loliginidae, os quais indicaram que a profundidade e a temperatura superficial do mar são as principais variáveis explanatórias. Uma Análise de Redundância (RDA) evidenciou os principais padrões de distribuição observados das três principais espécies de Loliginidae em relação às variáveis oceanográficas. D. sanpaulensis predominou na região norte da área de estudo, associada a águas frias e a eventos de ressurgência. D. plei ocorreu principalmente na região sul da área e em águas mais quentes. L. brevis foi encontrada apenas na região estuarina de Santos, em águas rasas e menos salinas. Os resultados obtidos representam uma contribuição relevante ao conhecimento sobre a Oceanografia Pesqueira das lulas no ecossistema marinho regional. / Loliginid squids are fisheries resources of increasing importance in the shelf ecosystem of Southeastern Brazil. Therefore, information about distribution of the early stages of their life cycle is scarce. Based on plankton samples collected by eleven historical oceanographic surveys cruises of the University of São Paulo\'s Oceanographic Institute between 1991 and 2005, the present study aimed identification of the occurrence of Loliginidae paralarvae in the region between Cabo de São Tomé (22ºS) and Cananéia (25ºS). From 664 samples analyzed, 246 paralarvae were found, being 121 identified to the species level, (Doryteuthis sanpaulensis n=75, Doryteuthis plei n=39,, Lolliguncula brevis n=6 and Pickfordiateuthis pulchella, n=1). The distributional patterns of Loliginidae in relation to oceanographic processes were identified by using horizontal and vertical maps of abundance, temperature and salinity. Generalized Linear Models (GLMs) were used to detect the factors that explain Loliginidae occurrence and abundance, which indicated that depth and sea surface temperature, were major explanatory variables. A Redundancy Analyses (RDA) showed the main observed distribution patterns of the three species of Loliginidae in relation to oceanographic variables. D. sanpaulensis occurred in the northern region associated to cold waters and upwelling events. D. plei occurred mainly in the southern region of the study area and in warmer waters.L. brevis was found in the estuarine region of Santos, in shallow and low salinity waters. The obtained results represent a relevant contribution to squids Fisheries Oceanography in the regional marine ecosystem.

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