Feeding ecology and predation impact of the recently established amphipod, Themisto libellula, in the St. Lawrence marine system, Canada
Themisto libellula was virtually absent from the St. Lawrence marine system (SLMS) before 1990. Since then, it has become an abundant, full-time resident of this system. Hyperiid amphipods of the genus Themisto are principally carnivorous and represent an essential link in the trophic pathway from s...
Published in: | Marine Ecology Progress Series |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | French |
Published: |
2008
|
Subjects: | |
Online Access: | https://semaphore.uqar.ca/id/eprint/1703/ https://semaphore.uqar.ca/id/eprint/1703/1/Alexandra_Marion_et_al_decembre2008.pdf https://doi.org/10.3354/meps07716 |
id |
ftunivquebecar:oai:semaphore.uqar.ca:1703 |
---|---|
record_format |
openpolar |
spelling |
ftunivquebecar:oai:semaphore.uqar.ca:1703 2023-05-15T15:48:04+02:00 Feeding ecology and predation impact of the recently established amphipod, Themisto libellula, in the St. Lawrence marine system, Canada Marion, Alexandra Harvey, Michel Chabot, Denis Brêthes, Jean-Claude 2008 application/pdf https://semaphore.uqar.ca/id/eprint/1703/ https://semaphore.uqar.ca/id/eprint/1703/1/Alexandra_Marion_et_al_decembre2008.pdf https://doi.org/10.3354/meps07716 fr fre https://semaphore.uqar.ca/id/eprint/1703/1/Alexandra_Marion_et_al_decembre2008.pdf Marion, Alexandra et Harvey, Michel et Chabot, Denis et Brêthes, Jean-Claude (2008). Feeding ecology and predation impact of the recently established amphipod, Themisto libellula, in the St. Lawrence marine system, Canada. Marine Ecology Progress Series, 373 . p. 53-70. Article Évalué par les pairs 2008 ftunivquebecar https://doi.org/10.3354/meps07716 2022-07-20T06:19:35Z Themisto libellula was virtually absent from the St. Lawrence marine system (SLMS) before 1990. Since then, it has become an abundant, full-time resident of this system. Hyperiid amphipods of the genus Themisto are principally carnivorous and represent an essential link in the trophic pathway from secondary production to higher trophic levels. Sampling of T. libellula was carried out in the lower St. Lawrence Estuary (LSLE) and the northwest Gulf of St. Lawrence (NWGSL) in the fall of 1998, 2003 and 2004 to study the feeding dynamics and predation impact of this species on mesozooplankton and macrozooplankton communities. Our results showed that T. libellula was an opportunistic predator with a circadian feeding cycle; activity was higher during the second part of the night and the sunrise period. Stomach content analyses showed that these amphipods consumed chiefly copepods, in particular, the copepodite stages CIV and CV of Calanus finmarchicus. Euphausiids, chaetognaths, amphipods and mysids constituted other important prey. Digestion time was estimated at 13 h. The daily ingestion rate of T. libellula was estimated using 2 approaches: (1) stomach fullness index and (2) mean number of prey removed per unit of time and converted to prey biomass using the stage-species dry masses of each prey item. We found that the daily ingestion rate of T. libellula ranged from 6.32 to 16.82% of body dry mass per day in both study areas (LSLE and NWGSL). Concerning predation impact, T. libellula consumed between 0.14 and 1.79% of the combined mesozooplankton and macrozooplankton standing stock per day and between 0.43 and 2.48% of the C. finmarchicus standing stock. Themisto libellula may thus exert a significant control on the mesozooplankton and macrozooplankton communities in the SLMS through direct predation. -- Keywords : Hyperiid amphipod Themisto libellula Feeding ecology Ingestion rate Digestion time Predation impact Gulf of St. Lawrence. Article in Journal/Newspaper Calanus finmarchicus Themisto libellula Copepods Université du Québec à Rimouski (UQAR): Sémaphore Canada Marine Ecology Progress Series 373 53 70 |
institution |
Open Polar |
collection |
Université du Québec à Rimouski (UQAR): Sémaphore |
op_collection_id |
ftunivquebecar |
language |
French |
description |
Themisto libellula was virtually absent from the St. Lawrence marine system (SLMS) before 1990. Since then, it has become an abundant, full-time resident of this system. Hyperiid amphipods of the genus Themisto are principally carnivorous and represent an essential link in the trophic pathway from secondary production to higher trophic levels. Sampling of T. libellula was carried out in the lower St. Lawrence Estuary (LSLE) and the northwest Gulf of St. Lawrence (NWGSL) in the fall of 1998, 2003 and 2004 to study the feeding dynamics and predation impact of this species on mesozooplankton and macrozooplankton communities. Our results showed that T. libellula was an opportunistic predator with a circadian feeding cycle; activity was higher during the second part of the night and the sunrise period. Stomach content analyses showed that these amphipods consumed chiefly copepods, in particular, the copepodite stages CIV and CV of Calanus finmarchicus. Euphausiids, chaetognaths, amphipods and mysids constituted other important prey. Digestion time was estimated at 13 h. The daily ingestion rate of T. libellula was estimated using 2 approaches: (1) stomach fullness index and (2) mean number of prey removed per unit of time and converted to prey biomass using the stage-species dry masses of each prey item. We found that the daily ingestion rate of T. libellula ranged from 6.32 to 16.82% of body dry mass per day in both study areas (LSLE and NWGSL). Concerning predation impact, T. libellula consumed between 0.14 and 1.79% of the combined mesozooplankton and macrozooplankton standing stock per day and between 0.43 and 2.48% of the C. finmarchicus standing stock. Themisto libellula may thus exert a significant control on the mesozooplankton and macrozooplankton communities in the SLMS through direct predation. -- Keywords : Hyperiid amphipod Themisto libellula Feeding ecology Ingestion rate Digestion time Predation impact Gulf of St. Lawrence. |
format |
Article in Journal/Newspaper |
author |
Marion, Alexandra Harvey, Michel Chabot, Denis Brêthes, Jean-Claude |
spellingShingle |
Marion, Alexandra Harvey, Michel Chabot, Denis Brêthes, Jean-Claude Feeding ecology and predation impact of the recently established amphipod, Themisto libellula, in the St. Lawrence marine system, Canada |
author_facet |
Marion, Alexandra Harvey, Michel Chabot, Denis Brêthes, Jean-Claude |
author_sort |
Marion, Alexandra |
title |
Feeding ecology and predation impact of the recently established amphipod, Themisto libellula, in the St. Lawrence marine system, Canada |
title_short |
Feeding ecology and predation impact of the recently established amphipod, Themisto libellula, in the St. Lawrence marine system, Canada |
title_full |
Feeding ecology and predation impact of the recently established amphipod, Themisto libellula, in the St. Lawrence marine system, Canada |
title_fullStr |
Feeding ecology and predation impact of the recently established amphipod, Themisto libellula, in the St. Lawrence marine system, Canada |
title_full_unstemmed |
Feeding ecology and predation impact of the recently established amphipod, Themisto libellula, in the St. Lawrence marine system, Canada |
title_sort |
feeding ecology and predation impact of the recently established amphipod, themisto libellula, in the st. lawrence marine system, canada |
publishDate |
2008 |
url |
https://semaphore.uqar.ca/id/eprint/1703/ https://semaphore.uqar.ca/id/eprint/1703/1/Alexandra_Marion_et_al_decembre2008.pdf https://doi.org/10.3354/meps07716 |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Calanus finmarchicus Themisto libellula Copepods |
genre_facet |
Calanus finmarchicus Themisto libellula Copepods |
op_relation |
https://semaphore.uqar.ca/id/eprint/1703/1/Alexandra_Marion_et_al_decembre2008.pdf Marion, Alexandra et Harvey, Michel et Chabot, Denis et Brêthes, Jean-Claude (2008). Feeding ecology and predation impact of the recently established amphipod, Themisto libellula, in the St. Lawrence marine system, Canada. Marine Ecology Progress Series, 373 . p. 53-70. |
op_doi |
https://doi.org/10.3354/meps07716 |
container_title |
Marine Ecology Progress Series |
container_volume |
373 |
container_start_page |
53 |
op_container_end_page |
70 |
_version_ |
1766383070342021120 |