Appendicularians and copepods from Scotia Bay (Laurie island, South Orkney, Antarctica): fluctuations in community structure and diversity in two contrasting, consecutive summers (original) (raw)
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Copepods: Main Zooplankters in Admiralty Bay, King George Island, Antarctica
INCT-APA Annual Activity Report, 2015
Copepods have a major role in zooplankton communities worldwide and are very important in Polar ecosystems; they form the base of the trophic web, contributing through accumulation of great energy reserves. For this work, fifty five samples were collected in Admiralty Bay, King George Island, Antarctica during the summer of 2009. A total of 15,328 copepods were sorted, Rhincalanus gigas, Macrosetella gracilis, Clausocalanus sp. and another five taxa were identified.
Copepods in sea ice of the western Weddell Sea during austral spring 2004
Deep Sea Research Part II: Topical Studies in Oceanography, 2008
In the framework of the R.V. Polarstern expedition ''Ice station POLarstern'' (ISPOL) spatial and temporal trends in composition, abundance and age structure of sea ice inhabiting copepods were investigated in the western Weddell Sea during the transition from the spring to the summer state. For the spatial scale, sea-ice coring was performed at six locations on a transect from the ice edge to the icedrift station between 14 and 24 November 2004. The temporal changes were investigated in a time series study on a drifting sea-ice floe from 29 November to 30 December 2004. A relatively large number of copepod species (15) were found in the ice with a higher number at the time station (13) than at the transect (9). Drescheriella spp. was by far the most abundant taxon encountered in the sea ice throughout the present study (72-87%). On the transect, Idomene antarctica ranked second in abundance (7%) followed by Stephos longipes (2%) and Ectinosoma sp. (2%). In contrast, Diarthrode cf. lilacinus, which was not found on the transect, was the second most abundant species (11%) at the time station, followed by I. antarctica (9%), Ectinosoma sp. (6%) and S. longipes (1%). Naupliar stages dominated the populations of Drescheriella spp. and S. longipes both on the transect and during the time series. The Ectinosoma sp. population was dominated by nauplii only at the stations of the transect, while copepodite stages made up the largest fraction during the time series. Copepodids always predominated the I. antarctica populations, and it was the only species in which adults occurred in high densities contributing significantly to the abundance. Only Drescheriella spp. and S. longipes occurred throughout the sea-ice cores, while the occurrence of all other species was restricted to the bottom layer of the ice. The distribution of all species was very patchy and varied greatly between the sampling sites. r
Copepods in spring annual sea ice at Terra Nova Bay (Ross Sea, Antarctica)
Polar Biology, 2007
The aim of this study was to investigate patterns of abundance, distribution, temporal changes and species composition of the dominant ice-associated copepods in the spring annual pack ice, platelet ice and water column at Terra Nova Bay, Ross Sea, during late spring 1997. Ice cores were drilled for temporal and spatial scales. Stephos longipes and Harpacticus furcifer dominated the sea ice meiofauna in terms of numbers in the lower few centimeters of the bottom ice associated with high chlorophyll a and phaeopigment levels. Nauplii dominated the S. longipes population (91.6%) and occurred in extremely high concentrations. In contrast, copepodids were the dominant stages in H. furcifer. How H. furcifer carries out its entire life cycle and how it diVers from ecologically similar species such as Drescheriella glacialis should be examined in more detail.
Spatial distribution of Antarctic copepods in Fíldes Bay during summer of 2012
Revista De Biologia Marina Y Oceanografia, 2014
Resumen.-La Península Antártica Chilena, se caracteriza por ser estable en su condición oceanográfica, sin embargo sus zonas costeras como bahías pueden presentar condiciones físicas variables tanto espacial como temporalmente. Se ha señalado que existe una importante interacción entre las condiciones oceanográficas y patrones de distribución espacial del zooplancton, sin embargo, no existe mayor evidencia acerca de cómo esta interacción afecta la distribución horizontal y vertical del zooplancton que habita estas zonas. El presente estudio muestra evidencias de los cambios que ocurren a nivel de estructura comunitaria del zooplancton, específicamente en el ensamble de copépodos al inte rior de Bahía Fíldes. Los resultados muestran que copépodos de la familia Oithonidae son abundantes en zonas costeras de la bahía mientras que copépodos de la familia Calanidae son abundantes en zonas contiguas al Estrecho Bransfield encontrándose en escasa abundancia al interior de la bahía. Estos hallazgos indican que existen diferencias en el ensamble de copépodos a lo largo de la bahí a con cambios en términos de abundancia y distribución de grupos dominantes enc ontrados comúnmente en la Península Antártica y aguas cercanas al paso Drake.
Epipelagic copepod assemblage in the Gerlache Strait (Antarctica) during the 2015 austral summer
Bulletin of Marine and Coastal Research
Oblique zooplankton tows were carried out in the Gerlache Strait from 17 to 22 January 2015 as part of the first Colombian oceanographic expedition to the Antarctic continent, to document the composition and structure of the epipelagic copepod assemblage, taking into account variations at a small spatial scale. The epipelagic environment of the Gerlache Strait was divided into two oceanographic regions during sampling: a stratified northern region and a homogeneous southern region. The epipelagic copepod assemblage comprised 17 species belonging to four orders and 13 families. Adult copepods as well as developmental stages ranging from copepodite II (C2) to copepodite V (C5) from eight different species were recorded in the study area. The dominant species by number was Oithona similis, followed by O. frigida, Ctenocalanus citer, Drescheriella glacialis, and Calanoides acutus. There were significant differences between the epipelagic copepod assemblages present in the northern and s...
Spatial distribution of copepods in fast ice of eastern Antarctica
2000
The distribution and abundance of sympagic copepods in fast ice of the Australian Antarctic Territory (AAT) were investigated between October and December 1995. Copepods were collected from six sites between the northern Vestfold Hills (Murphy Rocks) and Mawson Station, a distance of approximately 650 km. Nine species of copepods were identified from the ice cores, however, of these only three were recorded regularly: Paralabidocera antarctica, Drescheriella glacialis and Stephos longipes. The density of copepods was highest in the bottom few cm of ice, with abundances reaching up to 147 1 ' . The highest concentrations of chlorophyll a were also found in the bottom portion of ice, suggesting that the copepods congregated in regions of high food availability. All developmental stages of Drescheriella glacialis were observed during this study, often from within a single core. In contrast, Paralabidocera antarctica occurred mainly as early copepodite stages, and Stephos longipes mainly as nauplii. These observations were consistent with the documented life cycles for each species. Drescheriella glacialis appears to reproduce and breed within the ice, Paralabidocera antarctica overwinters in the ice but enters a pelagic phase as late-stage copepodids, while nauplii of Stephos longipes are the predominant stages which associate closely with sea ice.
Hydrobiologia, 2007
A new harpacticoid copepod species was found during a year round plankton survey in a shallow Antarctic bay. Both the dominant Calanoida and Cyclopoida and the often neglected Harpacticoida, their abundances in relation to sea-ice formation and decline in presence of Euphausia superba are regarded, in this study. Alteutha potter sp. n. (Peltidiidae) was collected in Potter Cove, King George Island, Antarctica. While its geographical region occurrence and planktonic life style are comparable to many of its congeners, morphological characters such as shape and setation of the maxilliped and the almost complete fusion of the baseoendopod and the exopod of the fifth leg in the female are described for the first time for this genus. Morphological peculiarities such as the lack, the deformation or fusion of setae on only one body side have been detected in several specimens. This copepod species is obviously sea-ice related. Its abundances in the plankton reached a maximum under the winter sea-ice. The year round population structure did not show very high variability whereas ovigerous females mostly occurred in spring and summer. Assuming different possible ecological strategies and environmental temperatures generation times between 46 and 77 days are calculated for A. potter sp. n.
Polar Science, 2017
Copepods are one of the most important components of the Southern Ocean food web, and are widely distributed from surface to deeper waters. We conducted discrete depth sampling to clarify the community structure of copepods from the epi-to bathypelagic layers of the oceanic and neritic waters off Ad elie and George V Land, East Antarctica, in the austral summer of 2008. Notably high diversity and species numbers were observed in the meso-and bathypelagic layers. Cluster analysis based on the similarity of copepod communities identified seven cluster groups, which corresponded well with water masses. In the epi-and upper-mesopelagic layers of the oceanic zone, the SB (Southern Boundary of the Antarctic Circumpolar Current) divided copepod communities. Conversely, in the lower meso-and bathypelagic layers (500e2000 m depth), communities were consistent across the SB. In these layers, the distributions of copepod species were separated by habitat depth ranges and feeding behaviour. The different food webs occur in the epipelagic layer with habitat segregation by zooplankton in their horizontal distribution ranges.
Journal of Plankton Research, 2002
Paraeuchaeta antarctica (Giesbrecht, 1902) is the most commonly recorded species of the copepod family Euchaetidae throughout the Antarctic, and also occurs, usually in small numbers, in subantarctic sectors of the Atlantic, Indian and Pacific oceans (Fontaine, 1988; Park, 1994). The species inhabits mainly mesopelagic waters but is also found in the epipelagic and bathypelagic (Fontaine, 1988; Zmijewska, 1993; Mazzocchi et al., 1995). It is a fairly large [body length and body mass up to 10 mm and 18 mg, repectively; (Fontaine, 1988) and authors' unpublished data] carnivorous species, which is equipped with a pair of feeding appendages allowing it to capture smaller copepods (Hopkins, 1987; Øresland, 1991; Yen, 1991). Paraeuchaeta antarctica therefore acts as a