Submitted by Caroline Falcao (caroline.rfalcao@ufpe.br) on 2017-06-29T17:35:04Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) 2011-Dissertação-TiagoNunes.pdf: 14422947 bytes, checksum: c5fe4454b1a2c027cf01d48b6015c9ca (MD5) / Made available in DSpace on 2017-06-29T17:35:04Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) 2011-Dissertação-TiagoNunes.pdf: 14422947 bytes, checksum: c5fe4454b1a2c027cf01d48b6015c9ca (MD5) Previous issue date: 2011-02-28 / Os anfípodos zooplanctônicossão componentes significativos das comunidades epi e mesopelágicas. Ocupam nichos ecológicos diversificados e, em algumas regiões frias, dominam a biomassa planctônica, constituindo os principais itens alimentares depeixes e baleias planctófagos. Como dados sobre composição específica e variabilidade geográfica ainda são escassos especialmente para o oceano Atlântico Sul Ocidental, objetivou-se levantar a composição dos Amphipodapresentes emáguas oceânicas da Zona Econômica Exclusiva (ZEE) do Nordeste do Brasil, contribuindo para o conhecimento taxonômico de distribuição horizontal. Duas hipóteses foram testadas:1) possuem alta diversidade na área, constituindo uma comunidade complexa, porém, pouco abundante; 2) há espécies que ocorrem exclusivamente na região, em relação às demais águas brasileiras. Um total de 43 amostras de macrozooplâncton foi analisado,amostras essas coletadas entre junho e julho de 1998 nas áreas: Oceânica Este (OE), Arquipélago São Pedro e São Paulo (ASPSP) e Cadeia Rocas/Noronha (CRN), parte integrante do Projeto REVIZEE Score NE-III. As amostras foram obtidas no estrato de0 a200m através de arrastos oblíquos, com rede de náilon do tipo bongo, com abertura de malha de 300μme 500μmdurante 15 minutos,acoplada com fluxômetro digital. Para este trabalho foi utilizado o material retido na malha de 300μm. Dados de temperatura e salinidade foram igualmente aferidos. O material biológico foi fixado a bordo, emuma solução de formaldeído a 4% neutralizado com tetraborato de sódio. Os indivíduos foram separados, dissecados e identificados até a menor unidade taxonômica possível. Observou-se uma densidade máxima de 1,92 org.m-3na E111 (ASPSP), e uma mínima de 0,175 org.m-3na E143 (OE). Foram identificadas 68 espécies, sendo 5 da subordem Gammaridea e 63 da Hyperiidea, além de cinco instantes de associação com organismos gelatinosos. Eupronoe intermedia, Hyperietta vosseleri, Anchylomera blossevillei,Phronimella elongata,Lycaeopsis zamboangaee Primno latreilleiforam consideradas muito frequentes, sendo as quatro primeiras aquelas que se sobressaíram em abundância (12,6%; 21,4%; 11,5%; 10,2%, respectivamente), consideradas pouco abundantes, e todas as outras, raras. O ASPSP foi a área que apresentou maior diversidade e equitabilidade (4,248 bits.ind-1e E= 0,761). Segue-se a elea CRN (3,878 bits.ind-1e E= 0,744) e a OE (3,766 bits.ind-1e E= 0,654). Esses valores expressam uma altaequitabilidade e diversidade para a área estudada, quando comparados a valores encontrados na literatura para outras áreas marinhas do Brasil e do mundo; a primeira, expressando uma boa distribuição dos organismos ao longo da coluna d’água, e a segunda, corroborando a hipótese de que os anfípodos zooplanctônicos apresentam, da zona nerítica em direção à oceânica, uma diminuição na densidade e aumento na diversidade. Este estudo contribui ainda com sete novas ocorrências para o Nordeste do Brasil e duas para o Atlântico Sul Ocidental. / Zooplanktonic amphipods are significant components of the epi-and mesopelagic communities. They occupy diverse ecological niches and, in some cold regions, dominate the plankton biomass, constituting the food bank for fish and plankton whales. Given the data on species composition and geographic variability are scarce, especially for the South Atlantic Ocean, the main goal of thisdissertation was to register the composition of crustaceans found in ocean waters of the Exclusive Economic Zone (EEZ) of the Northeast of Brazil, contributing to the knowledge of the taxonomy and biogeography of this group. Two hypothesis were tested: (1) the diversity of zooplanktonic amphipods at this area is high, representing a complex but not abundant community; (2) there are exclusive species at the region level in comparison to other Brazilian marine areas. I analyzed 43 samples of macrozooplankton collected between June and July 1998 in: Oceânica Este (OE), São Pedro and São Paulo archipelagos (SP/SP) and Cadeia Rocas/Noronha (CRN). All samples were obtained in a depth between 0 e 200m by through oblique hauls lasting 15 minutes with a nylon mesh-type bong, with the gap between 300μm mesh coupled with digital flowmeter. Biological material was fixed aboard with formaldehyde 4% neutralized with sodium tetraborate. Individuals were dissected and identified at the lowest taxonomic level it was possible. It was observed the maximum density of 1,92 org.m-3at E111 (SP/SP), and the minimum density of 0,175 org.m-3at E143 (OE). I identified 68species: 5 fromthe sub-order Gammaridea and 63 from the sub-order Hyperiidea; five associations with gelatinous zooplankton were also found. Eupronoe intermedia, Hyperietta vosseleri, Anchylomera blossevillei,Phronimella elongata,Lycaeopsis zamboangaeand Primno latreilleiwere considered frequent species. Among them, the first four species were also considered not abundant (12,6%; 21,4%; 11,5%; 10,2%, respectively).SP/SP was the area with the highest diversity and evenness(4,248 bits.ind-1; E= 0,761), followed by CRN (3,878 bits.ind-1; E= 0,744) and OE (3,766 bits.ind-1; E= 0,654). Thesevalues expressahigh evennessand diversityin the studyareawhen compared tovalues foundin the literature forothers Brazilianand globalmarine areas. Evenness results expressingagooddistribution of organismsthroughout thewater column; and diversity values are supporting the hypothesisthat zooplanktonic amphipodsexhibita decreasein the density andincreasein the diversity, from theneriticzonetoward theoceanic zone. Seven species are new register for the Northeastern region of Brazil and other two species, for Western South Atlantic (also exclusively occurring at Northeastern region).

This research focused on population dynamics of two gelatinous zooplankters (Aequorea & Pyrosoma atlanticum) in the northern California Current to assess their relationship to environmental conditions and role in the pelagic ecosystem. Data collected since 1999 showed seasonal and interannual fluctuations in the abundance and distribution of Aequorea in the NCC, with a positive correlation with sea surface temperature and salinity. Pyrosoma atlanticum, which are typically found in tropical waters, have only been observed in high abundances in the NCC since 2014 and their role in the pelagic ecosystem is not well understood. Pyrosome abundance related to in situ environmental variables showed a positive correlation with warmer SST. We also used fatty acids as trophic markers to better understand pyrosome trophic ecology in the NCC. FA biomarkers suggest that pyrosomes have a broad phytoplankton diet, which may indicate an ability to inhabit warmer, lower nutrient zones. / 2020-01-11

The distribution, abundance, chemical composition, metabolism, and feeding ecology of the tentaculate ctenophore, Callianira antarctica (Chun 1897), were investigated during austral winter 2001and autumn & winter 2002, in the vicinity of Marguerite Bay west of the Antarctic Peninsula. Callianira antarctica had a widespread distribution during autumn and winter, and variable abundance (0.02 to 2.6 ind. m-2) during winter 2001 associated with specific circulation features. Size frequency distributions for autumn and winter suggest that more than half of the C. antarctica population may have experienced 'degrowth' during winter due to low food availability. Callianira antarctica is a fairly robust ctenophore with geometric mean (geomean) carbon (C) and nitrogen (N) values of 8.41 and 1.83% dry weight (DW), respectively. Winter oxygen consumption and ammonium excretion rates ranged from 0.059 to 0.410 micro l O2 [mg DW]-1 h-1 and 0.60 to 31.1 µg-at N [g DW]-1 h-1, respectively, at 0oC. Daily minimum maintenance rations based on respiration experiments were 2.7% to 3.6% of the total body carbon (TBC) for small ctenophores, and 1.4% to 1.9% TBC for larger ctenophores. Calanoid copepods and larval and juvenile Antarctic krill were offered to ctenophores in incubation experiments. Digestion times were variable, lasting 8 to 20 h, and were independent of ctenophore size and dependent on number and type of prey. Gut content analysis from one autumn and two winter seasons indicated C. antarctica preyed on both copepods and krill in situ, with an increased dependence on larval krill during winter. Lipid biomarker analysis on C. antarctica and their potential prey confirmed these results. Divers observed aggregations of C. antarctica passively drifting with tentacles extended near dense concentrations of larval Euphausia superba during winter. These observations along with gut content and lipid biomarker analysis suggest that larval krill is an important prey item for C. antarctica during winter.

Members of the family Platytroctidae (tubeshoulders) are found throughout the meso- and bathypelagic waters of the World Ocean. Due to the lack of specimens collected globally, this taxon has received little attention, despite recent evidence suggesting its predominance in the bathypelagic biome. Prior to this study, only four species had been reported in the Gulf of Mexico’s (GoM) highly diverse deep-pelagic ecosystem. An extensive meso- and bathypelagic trawl series in the GoM allowed a detailed examination of this family, which included analyses of species composition, abundance, vertical distribution, sex ratios, and trophic ecology. A total of 16 species were collected, which included 12 new records for the GoM. The five most-abundant species collected were Mentodus facilis, Platytroctes apus, Barbantus curvifrons, Mentodus mesalirus, and Maulisia microlepis. All platytroctids were collected from tows that extended below 700 m. Mentodus facilis was the only species that significantly differed from the expected 1:1 sex ratio (pMentodus mesalirus and Maulisia microlepis heavily consumed gelatinous zooplankton. Mentodus facilis and Barbantus curvifrons had a more varied diet consuming chaetognaths, copepods, and ostracods, with M. facilis exhibiting a slightly greater reliance on ostracods and gelatinous prey. This study represents the first investigation into the diet of this fish family and adds to the sparse community data of the bathypelagic zone by identifying alternative nutrient pathways (e.g., the fish-jelly link) that connect the deep and upper oceanic ecosystems.