In August, 1959, Pacific Marine Station became an active participant in the California Co-operative Oceanic Fisheries Investigations (C.C.O.F.I.). The program began in 1949 as an investigation of factors that might be associated with the disappearance of the California Sardine. Since that time, the general scope and purpose has broadened, and new information about the coastal water of California has been obtained. With each passing year, more information is being gathered and put to use. Participation in this program by Pacific Marine Station has consisted of taking monthly oceanographic observations near the head of Bodega Submarine Canyon, twenty-five miles west of Bodega. Along with routine plankton tows taken for the C.C.O.F.I program, another tow was taken which was retained at Pacific Marine Station. From the latter, I have taken the material for the following report. Chaetognaths were present in every tow, in varying numbers and species. One species in particular was thought to be out of place inn our tows (this was recently described as a new species by Alvarino, 1962). This paper is a discussion of the chaetognaths obtained in the tows over a fourteen-month period, and their relations to water movements in the vicinity of the sampling station.

Thesis (M.Sc. (Zoology & Entomology)) - Rhodes University, 2009.

Abstract There are 22 species of chaetognaths belonging 11 genera and 4 families found in coastal waters around the Kaohsiung and Liuchiu Yu Island from March 1997 to February 1998. The average abundance of chaetognaths was 2527 ¡Ó1659 ind./100m3. The 5 most dominant species were Flaccisagitta enflata, Aidanosagitta crassa, Sagitta bipuncata, Ferosagitta ferox and Serratosagitta pacifica, and comprised > 95% of total chaetognaths. Fl. efnlata was the most common and abundance species, its number occupied 70% of total chaetognaths and occurred in every station. These dominant species showed significant seasonal succession, in that, Fl. Enflata could be found in all seasons, while S. bipuncata was found only in fall and winter. Most of chaetognaths found in this study were pelagic, tropical and temperate species, and most of them are widely distributed in the Pacific, the Atlantic and the Indian ocean (50% of total species), and in the Indian and the Pacific ocean (41% of total species). In terms of ecological distribution patterns, warm euryhaline species (i.e. Fl. Enflata and Fe. ferox), and warm hyperhaline species (i.e. S. bipuncata and Se. pacifica) dominated in this study areas. The abundance of chaetognaths was higher in fall (4721 ¡Ó8435 ind./100m3) and the lower in spring (1077 ¡Ó995 ind./100m3). The horizontal distribution of chaetognaths was apparently influenced by the runoff of Kaohsiung Habor and Kaoping River, and the peak abundance was usually found in the front of Kaoping river plume. Most chaetognaths (over 60% of total amount) were found in the surface waters (0-5 m), and its abundance abruptly decreased with depth. The scales of day/night vertical migration of chaetognaths were small (generally less than 50 m). Three types of vertical migration were distinguished in this study: Nocturnal migration (i.e. Fl. Enflata and Se. pacifica). Reverse migration (i.e. S. bipuncata ), and Non-migration (i.e. Fe. ferox). The vertical distribution and the distance of vertical migration of most chaetognaths, however, varied seasonally.

No description available.

Made available in DSpace on 2015-04-17T14:55:21Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 516894 bytes, checksum: 1071d1e7f53386e40b6eb5baff950404 (MD5) Previous issue date: 2010-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The evolutionary affinities of Chaetognatha were tested under phylogenetic methods and the phylogeny of Deuterostomia was reconstructed. Deuterostomia + Chaetognatha formed the ingroup and Ectoprocta, Brachiopoda, Pterobranchia, Echinodermata, Enteropneusta, Tunicata, Cephalochordata, and Craniata were the terminal taxa, in addition to Chaetognatha. Oweniida, Pogonophora (Frenulata + Vestimentifera), and Phoronida formed the outgroup. The general anatomy of the group was analyzed and, from this process, the most informative characters were selected from the primary literature. The primary homology hypotheses were firstly built and subsequently tested with an appropriate congruence test, the parcimony in this case. Twenty five characters were selected, seventeen are multistate and eight are binary. The character matrix construction and the parcimony analysis were performed with the TNT 1.1 package. All characters were treated how unordered and received identical weights. Just one most parcimonious tree was recovered (length 59, consistence index 0.91 and retention index 0.90). The deuterostome monophyly, plus Chaetognatha, Ectoprocta and Brachiopoda, was recovered. Chaetognatha was recovered most closely related to Craniata, in a terminal position into the cladogram, supported by the characters 082, 16, 202 e 213 e 251 from the Table 4. / As relações evolutivas de Chaetognatha foram testadas com a utilização de métodos filogenéticos e a filogenia de Deuterostomia foi reconstruída. Deuterostomia + Chaetognatha formaram o grupo interno desta análise e os táxons terminais foram Ectoprocta, Brachiopoda, Pterobranchia, Echinodermata, Enteropneusta, Tunicata, Cephalochordata e Craniata, além de Chaetognatha. Como grupos externos foram utilizados os táxons Oweniida, Pogonophora (Frenulata + Vestimentifera) e Phoronida. A anatomia geral do grupo foi analisada e a partir dela foram selecionados os caracteres mais informativos com base na literatura primária. As hipóteses de homologia primária foram primeiramente levantadas e subsequentemente sujeitas a um teste de congruência adequado, que neste caso foi a análise de parcimônia. Foram selecionados 25 caracteres, dos quais 17 são multiestado e 8 são binários. A construção da matriz de caracteres e a análise de parcimônia foi efetuada com auxílio do programa TNT 1.1. Todos os caracteres foram tratados como não ordenados e receberam peso 1 . Foi obtida apenas uma árvore mais parcimoniosa, com tamanho 59, índice de consistência 0.91 e índice de retenção 0.90. A monofilia de Deuterostomia, com a inclusão de Chaetognatha, Ectoprocta e Brachiopoda foi recuperada. Chaetognatha foi recuperado como grupo irmão de Craniata, em uma posição terminal no cladograma, com base nos caracteres 082, 16, 202 e 213 e 251 da Tabela 4.

Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-01-31T00:15:23Z No. of bitstreams: 1 414944.pdf: 16958092 bytes, checksum: ff4bab68a6bf2a9ec7394da48a728674 (MD5) / Made available in DSpace on 2018-01-31T00:15:23Z (GMT). No. of bitstreams: 1 414944.pdf: 16958092 bytes, checksum: ff4bab68a6bf2a9ec7394da48a728674 (MD5) Previous issue date: 2000-04-25 / CAPES / Nas últimas décadas, a baía de Guanabara vem sendo submetida a uma forte influência antrópica e o estudo de organismos pelágicos é fundamental para avaliar e acompanhar este processo. Os Chaetognatha vivem nos oceanos de todo o mundo. Sua distribuição vertical é resultado de migrações ontogenéticas e de variações ambientais. Esta dissertação objetiva avaliar a distribuição vertical das espécies do Filo Chaetognatha em um ponto fixo na baía de Guanabara. Foram feitas amostragens à superfície e próximo ao fundo durante cinco ciclos de maré, no canal central de circulação de água da baía, a fim de estabelecer os padrões de distribuição dos Chaetognatha, no inverno de 1995 e no verão de 1996. Sagitta friderici, Sagitta enflata e Krohnitta pacifica, foram identificadas nas amostras. S. friderici, a mais abundante, é uma espécie de população residente na baía de Guanabara. Esta espécie migra nictemeralmente, migra nictemeralmente, ocupando os estratos superficiais durante a noite. S. enflata, a segunda mais abundante, é bastante associada à entrada subsuperficial da água costeira adjacente à baía. S. friderici e S. enflata distribuem-se ontogeneticamente na coluna d'água. Os indivíduos jovens permanecem mais associados às águas superficiais. Sazonalidade e maré não influenciam significativamente a distribuição dos Chaetognatha na coluna d'água, neste ponto da baía de Guanabara. / The Guanabara Bay had been submited to a strong anthropic influence and the study of pelagic organisms is fundamental to evaluate and accompany this process . The chaetognaths lives in all oceans of the world . Their vertical distribution is result of ontogenetic migrations and environmental variations . The purpose of this study is evaluate the vertical distribution of the Phylum Chaetognatha species at one fixed point of Guanabara Bay . Surface and bottom samples were done during five tidal cycles at the central channel of water circulation of the bay, to establish the distribution patterns of the chaetognaths at winter of 1995 and summer of 1996. Sagitta friderici, Sagitta enflata and Krohnitta pacifica, were found in the samples. S. friderici, the most abundant, is one species who had a fixed population at Guanabara Bay. This species do nictemeral migration, following the more superficial strates during the night. S. enflata, the second most abundant, is very associated to the subsuperficial enter of the coastal adjacent water. S. friderici and S. enflata are ontogenetically distributed at the water column. The young individuals still associated with the superficial water. Sazonality and tidal cycles had not significative difference to the chaetognath's distribution at the water column, at this point of the Guanabara Bay .

Trophodynamics of carnivorous zooplankton in the region of the Subtropical Convergence (STC) in the Indian sector of the Southern Ocean was investigated during austral autumn (April 2007) as part of the first cruise of the Southern Ocean Ecosystem Variability Study. Within the region of the study, the STC was well defined by the 14°C surface isotherm which separated the Agulhas Return Current and Subtropical water in the north from Sub-Antarctic waters to the south. Total average abundance (3.89 ± 5.46ind 100m-3) and biomass (0.14 ± 0.27mg Dwt 100m-3) of carnivorous zooplankton south of the front were significantly higher than the total average abundance (1.33 ± 1.81ind 100m-3) and biomass (0.03 ± 0.05mg Dwt 100m-3) north of the front (p<0.001). There were no significant correlations between the selected physico-chemical (temperature and salinity) and the biological (mesozooplankton abundance and biomass) variables and the total abundance and biomass of the carnivorous zooplankton during the investigation (p>0.05 in all cases). There was no evidence of enhanced biomass and abundance values at stations occupied in the immediate vicinity of the front. Total average carnivorous zooplankton abundance was dominated by chaetognaths (Eukrohnia hamata Möbius 1875, Sagitta gazellae Ritler-Záhony 1909 and S. zetesios Fowler 1905) and euphausiids (Nematoscelis megalops Sars 1883, Euphausia longirostris Hansen 1908 and E. spinifera Sars 1883), which contributed up to 86.58 ± 32.91% of the total counts. The total average biomass was dominated by euphausiids and amphipods (Themisto gaudichaudii Guérin-Méneville 1825, Phronima sedentaria Forsskål 1775 and Vibilia armata Bovallius 1887) which contributed up to 71.45 ± 34.85% of the total counts. In general the populations of both the euphausiids and amphipods were dominated by females while the chaetognaths were dominated by juveniles. Numerical analysis identified two major zooplankton groupings within the survey area which did not coincide with the water masses within the survey area. The SIMPER procedure of the PRIMER package indicated differences between the groups were mainly attributed to changes in the abundance of the numerically dominant species rather than the presence or absence of individual species. The absence of any significant spatial patterns in the distribution of the carnivorous zooplankton suggests that the STC did not act as a biogeographical barrier during the present study. The mean feeding rates of the chaetognaths E. hamata, S. gazellae and S. zetesios were 1.82 ± 0.85prey d-1, 3.63 ± 2.08prey d-1 and 2.18 ± 0.59prey d-1, respectively. These rates correspond to a combined predation impact equivalent to <5% of the mesozooplankton standing stock or <10% of the mesozooplankton secondary production. Mesozooplankton, comprising mainly copepods was the dominant prey in the guts of the three chaetognath species. Total predation impact of the euphausiids, chaetognaths and amphipods, estimated using published daily ration data, on the mesozooplankton standing stock and secondary production ranged from 0.01% to 1.53% and from 0.03% to 30.54%, respectively. Among the carnivorous zooplankton, chaetognaths were generally identified as the dominant predators of mesozooplankton. Low predation impact of selected carnivorous zooplankton suggested that these organisms contributed little to the vertical carbon flux within the region of investigation during the study.

No description available.

Zooplankton samples and water mass measurements were conducted along a 10 km long, east-west transect off the coast of southeast Florida during 2007. Temperature and salinity measurements were recorded using a conductivity-temperature-depth (CTD) sensor, and current direction and magnitude measurements were recorded using an acoustic Doppler current profiler (ADCP). Daylight zooplankton samples were collected using a 335 μm mesh bongo net at surface 0-25 m and 0-150 m (nearshore) and 0-200 m (offshore), at three stations, for 5 nonconsecutive months along the transect. Chaetognatha were separated from bulk zooplankton samples and identified to species; fifteen different species were found. Flaccisagitta enflata had the highest densities over the entire sampling period, followed by Serratosagitta serratodentata, and Krohnitta pacifica. ADCP data revealed the existence of a Subsurface Counter Current in conjunction with an offshore meander of the Florida Current during May, July, and September 2007. Abiotic data confirmed the presence of Continental Edge Water and Yucatan Water occupying different spatial and temporal scales, and the boundary between these two water masses existed as the western boundary of the Florida Current. The densities of each species were compared to the collection site’s temperature and salinity data. Densities of several species (Flaccisagitta enflata, Ferosagitta hispida, M. minima, and Sagitta bipuctata) demonstrated a correlation to temperature and S. bipunctata and Ferosagitta hispida showed a correlation to salinity. These species were associated with the front and peripheries of the Florida Current.