Feeding dynamics and distribution of the hyperiid amphipod, Themisto gaudichaudii (Guérin, 1828) in the polar frontal zone, Southern Ocean
The population structure and feeding dynamics of the hyperiid amphipod, Themisto gaudichaudii, was investigated during two cruises of the South African National Antarctic Programme conducted in the Indian sector of the Polar Frontal Zone during austral autumn (April) 2004 and 2005. During the 2004 c...
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ftrhodesunivcory:vital:5696 2023-05-15T14:00:06+02:00 Feeding dynamics and distribution of the hyperiid amphipod, Themisto gaudichaudii (Guérin, 1828) in the polar frontal zone, Southern Ocean Lange, Louise 2006 87 leaves pdf http://hdl.handle.net/10962/d1005382 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:5696 English eng Rhodes University Faculty of Science, Zoology and Entomology vital:5696 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:5696 http://hdl.handle.net/10962/d1005382 Lange, Louise Themisto gaudichaudii -- Antarctic Ocean Hyperiidae -- Antarctic Ocean Zooplankton -- Antarctic Ocean Thesis Masters MSc 2006 ftrhodesunivcory 2022-12-26T11:11:22Z The population structure and feeding dynamics of the hyperiid amphipod, Themisto gaudichaudii, was investigated during two cruises of the South African National Antarctic Programme conducted in the Indian sector of the Polar Frontal Zone during austral autumn (April) 2004 and 2005. During the 2004 cruise the frontal features that delimit the PFZ converged to form a single distinctive feature. In 2005, the research cruise was conducted in the vicinity of a cold-core eddy which was spawned from the Antarctic Polar Front. Total mesozooplankton abundance and biomass during the 2004 study ranged from 55.19 to 860.57 ind. m⁻³, and from 2.60 to 38.42 mg dwt m⁻³, respectively. In 2005 the abundance and biomass ranged from 23.1 to 2160.64 ind. m⁻³, and from 0.76 to 35.16 mg dwt m⁻³, respectively. The mesozooplankton community was numerically dominated by copepods, pteropods, and ostracods during both surveys. The abundance and biomass of Themisto gaudichaudii in the region of investigation was < 0.2 ind. m⁻³ (range 0.01 to 0.15 ind. m⁻³) and < 0.06 mg dwt m⁻³ (range 0.02 to 0.06 mg dwt m⁻³) during 2004, while in 2005 the abundance and biomass of the amphipod ranged from < 0.01 to 0.2 ind. m⁻³ and < 0.01 to 0.04 mg dwt m⁻³, respectively. These values correspond to < 1% of the total mesozooplankton abundance and biomass during both surveys. T. gaudichaudii exhibited no significant spatial patterns in abundance, biomass and total length during both 2004 and 2005 (p > 0.05 in all cases). A key feature of the two investigations was the virtual absence of juveniles (total length < 15 mm) among the amphipod population, supporting the suggestion that they exhibit strong seasonal patterns in reproduction. Gut content analysis during both years indicated that for both the male and female amphipods’, copepods were the most prevalent prey species found in stomachs, followed by chaetognaths and pteropods. Results of electivity studies indicate that T. gaudichaudii is an opportunistic predator, generally feeding ... Master Thesis Antarc* Antarctic Antarctic Ocean Mesozooplankton South African National Antarctic Programme Southern Ocean Copepods Rhodes University Cory: Repository Antarctic Antarctic Ocean Austral Indian Southern Ocean The Antarctic |
institution |
Open Polar |
collection |
Rhodes University Cory: Repository |
op_collection_id |
ftrhodesunivcory |
language |
English |
topic |
Themisto gaudichaudii -- Antarctic Ocean Hyperiidae -- Antarctic Ocean Zooplankton -- Antarctic Ocean |
spellingShingle |
Themisto gaudichaudii -- Antarctic Ocean Hyperiidae -- Antarctic Ocean Zooplankton -- Antarctic Ocean Lange, Louise Feeding dynamics and distribution of the hyperiid amphipod, Themisto gaudichaudii (Guérin, 1828) in the polar frontal zone, Southern Ocean |
topic_facet |
Themisto gaudichaudii -- Antarctic Ocean Hyperiidae -- Antarctic Ocean Zooplankton -- Antarctic Ocean |
description |
The population structure and feeding dynamics of the hyperiid amphipod, Themisto gaudichaudii, was investigated during two cruises of the South African National Antarctic Programme conducted in the Indian sector of the Polar Frontal Zone during austral autumn (April) 2004 and 2005. During the 2004 cruise the frontal features that delimit the PFZ converged to form a single distinctive feature. In 2005, the research cruise was conducted in the vicinity of a cold-core eddy which was spawned from the Antarctic Polar Front. Total mesozooplankton abundance and biomass during the 2004 study ranged from 55.19 to 860.57 ind. m⁻³, and from 2.60 to 38.42 mg dwt m⁻³, respectively. In 2005 the abundance and biomass ranged from 23.1 to 2160.64 ind. m⁻³, and from 0.76 to 35.16 mg dwt m⁻³, respectively. The mesozooplankton community was numerically dominated by copepods, pteropods, and ostracods during both surveys. The abundance and biomass of Themisto gaudichaudii in the region of investigation was < 0.2 ind. m⁻³ (range 0.01 to 0.15 ind. m⁻³) and < 0.06 mg dwt m⁻³ (range 0.02 to 0.06 mg dwt m⁻³) during 2004, while in 2005 the abundance and biomass of the amphipod ranged from < 0.01 to 0.2 ind. m⁻³ and < 0.01 to 0.04 mg dwt m⁻³, respectively. These values correspond to < 1% of the total mesozooplankton abundance and biomass during both surveys. T. gaudichaudii exhibited no significant spatial patterns in abundance, biomass and total length during both 2004 and 2005 (p > 0.05 in all cases). A key feature of the two investigations was the virtual absence of juveniles (total length < 15 mm) among the amphipod population, supporting the suggestion that they exhibit strong seasonal patterns in reproduction. Gut content analysis during both years indicated that for both the male and female amphipods’, copepods were the most prevalent prey species found in stomachs, followed by chaetognaths and pteropods. Results of electivity studies indicate that T. gaudichaudii is an opportunistic predator, generally feeding ... |
format |
Master Thesis |
author |
Lange, Louise |
author_facet |
Lange, Louise |
author_sort |
Lange, Louise |
title |
Feeding dynamics and distribution of the hyperiid amphipod, Themisto gaudichaudii (Guérin, 1828) in the polar frontal zone, Southern Ocean |
title_short |
Feeding dynamics and distribution of the hyperiid amphipod, Themisto gaudichaudii (Guérin, 1828) in the polar frontal zone, Southern Ocean |
title_full |
Feeding dynamics and distribution of the hyperiid amphipod, Themisto gaudichaudii (Guérin, 1828) in the polar frontal zone, Southern Ocean |
title_fullStr |
Feeding dynamics and distribution of the hyperiid amphipod, Themisto gaudichaudii (Guérin, 1828) in the polar frontal zone, Southern Ocean |
title_full_unstemmed |
Feeding dynamics and distribution of the hyperiid amphipod, Themisto gaudichaudii (Guérin, 1828) in the polar frontal zone, Southern Ocean |
title_sort |
feeding dynamics and distribution of the hyperiid amphipod, themisto gaudichaudii (guérin, 1828) in the polar frontal zone, southern ocean |
publisher |
Rhodes University |
publishDate |
2006 |
url |
http://hdl.handle.net/10962/d1005382 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:5696 |
geographic |
Antarctic Antarctic Ocean Austral Indian Southern Ocean The Antarctic |
geographic_facet |
Antarctic Antarctic Ocean Austral Indian Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctic Ocean Mesozooplankton South African National Antarctic Programme Southern Ocean Copepods |
genre_facet |
Antarc* Antarctic Antarctic Ocean Mesozooplankton South African National Antarctic Programme Southern Ocean Copepods |
op_relation |
vital:5696 https://corycommons.ru.ac.za/vital/access/manager/Repository/vital:5696 http://hdl.handle.net/10962/d1005382 |
op_rights |
Lange, Louise |
_version_ |
1766269106178228224 |