Comparative morphology of Southern Ocean Euphausia species: ecological significance of sexual dimorphic features
Species of the genus Euphausia dominate the euphausiid biomass of the Southern Ocean, the three largest being Euphausia superba, E. triacantha and E. crystallorophias. We measured a number of morphological features to identify differences between, and within, these species to obtain ecological insig...
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ftnerc:oai:nora.nerc.ac.uk:528850 2024-02-11T10:03:36+01:00 Comparative morphology of Southern Ocean Euphausia species: ecological significance of sexual dimorphic features Tarling, G.A. Hobbs, C. Johnson, M.L. Färber Lorda, J. 2020-11-03 text http://nora.nerc.ac.uk/id/eprint/528850/ https://nora.nerc.ac.uk/id/eprint/528850/1/Tarling%26Hobbs%20et%20al%20revised%20manuscript%20and%20figure_v2_clean.pdf https://link.springer.com/article/10.1007/s00300-020-02764-6 en eng Springer https://nora.nerc.ac.uk/id/eprint/528850/1/Tarling%26Hobbs%20et%20al%20revised%20manuscript%20and%20figure_v2_clean.pdf Tarling, G.A. orcid:0000-0002-3753-5899 Hobbs, C.; Johnson, M.L.; Färber Lorda, J. 2020 Comparative morphology of Southern Ocean Euphausia species: ecological significance of sexual dimorphic features. Polar Biology, 43. 2043-2058. https://doi.org/10.1007/s00300-020-02764-6 <https://doi.org/10.1007/s00300-020-02764-6> Publication - Article PeerReviewed 2020 ftnerc https://doi.org/10.1007/s00300-020-02764-6 2024-01-19T00:03:17Z Species of the genus Euphausia dominate the euphausiid biomass of the Southern Ocean, the three largest being Euphausia superba, E. triacantha and E. crystallorophias. We measured a number of morphological features to identify differences between, and within, these species to obtain ecological insights. Interspecifically, the greatest difference was carapace size, with that of E. superba being by far the largest and most variable. This likely reflects its prolific spawning capacity compared with other euphausiid species. E. triacantha exhibited an extended sixth abdominal segment that could facilitate greater levels of thrust in the tail flip escape response. The pleopods, which provide propulsion in forward swimming, were more than 50% larger in E. superba, indicating a greater capacity for directional movement at high velocities. E. crystallorophias had eyes that were almost double the size of those in E. superba and E. triacantha, which may help retain visual resolution within its under-ice habitat. Intraspecifically, we found the above morphological features differed little between sexes and developmental stages in E. crystallorophias and E. triacantha, but differed significantly in E. superba. Compared to females and juveniles, male E. superba had significantly larger eyes and pleopods, whilst the carapace in males became shorter as a proportion of body length during growth. These features indicate a greater capacity for searching and swimming in males, which, we hypothesise, increases their ability to locate and fertilise females. This morphological specialisation in male E. superba is indicative of comparatively greater inter-male competition resulting from its tendency to form large, dense swarms. Article in Journal/Newspaper Euphausia superba Polar Biology Southern Ocean Natural Environment Research Council: NERC Open Research Archive Southern Ocean Polar Biology 43 12 2043 2058 |
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Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
English |
description |
Species of the genus Euphausia dominate the euphausiid biomass of the Southern Ocean, the three largest being Euphausia superba, E. triacantha and E. crystallorophias. We measured a number of morphological features to identify differences between, and within, these species to obtain ecological insights. Interspecifically, the greatest difference was carapace size, with that of E. superba being by far the largest and most variable. This likely reflects its prolific spawning capacity compared with other euphausiid species. E. triacantha exhibited an extended sixth abdominal segment that could facilitate greater levels of thrust in the tail flip escape response. The pleopods, which provide propulsion in forward swimming, were more than 50% larger in E. superba, indicating a greater capacity for directional movement at high velocities. E. crystallorophias had eyes that were almost double the size of those in E. superba and E. triacantha, which may help retain visual resolution within its under-ice habitat. Intraspecifically, we found the above morphological features differed little between sexes and developmental stages in E. crystallorophias and E. triacantha, but differed significantly in E. superba. Compared to females and juveniles, male E. superba had significantly larger eyes and pleopods, whilst the carapace in males became shorter as a proportion of body length during growth. These features indicate a greater capacity for searching and swimming in males, which, we hypothesise, increases their ability to locate and fertilise females. This morphological specialisation in male E. superba is indicative of comparatively greater inter-male competition resulting from its tendency to form large, dense swarms. |
format |
Article in Journal/Newspaper |
author |
Tarling, G.A. Hobbs, C. Johnson, M.L. Färber Lorda, J. |
spellingShingle |
Tarling, G.A. Hobbs, C. Johnson, M.L. Färber Lorda, J. Comparative morphology of Southern Ocean Euphausia species: ecological significance of sexual dimorphic features |
author_facet |
Tarling, G.A. Hobbs, C. Johnson, M.L. Färber Lorda, J. |
author_sort |
Tarling, G.A. |
title |
Comparative morphology of Southern Ocean Euphausia species: ecological significance of sexual dimorphic features |
title_short |
Comparative morphology of Southern Ocean Euphausia species: ecological significance of sexual dimorphic features |
title_full |
Comparative morphology of Southern Ocean Euphausia species: ecological significance of sexual dimorphic features |
title_fullStr |
Comparative morphology of Southern Ocean Euphausia species: ecological significance of sexual dimorphic features |
title_full_unstemmed |
Comparative morphology of Southern Ocean Euphausia species: ecological significance of sexual dimorphic features |
title_sort |
comparative morphology of southern ocean euphausia species: ecological significance of sexual dimorphic features |
publisher |
Springer |
publishDate |
2020 |
url |
http://nora.nerc.ac.uk/id/eprint/528850/ https://nora.nerc.ac.uk/id/eprint/528850/1/Tarling%26Hobbs%20et%20al%20revised%20manuscript%20and%20figure_v2_clean.pdf https://link.springer.com/article/10.1007/s00300-020-02764-6 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Euphausia superba Polar Biology Southern Ocean |
genre_facet |
Euphausia superba Polar Biology Southern Ocean |
op_relation |
https://nora.nerc.ac.uk/id/eprint/528850/1/Tarling%26Hobbs%20et%20al%20revised%20manuscript%20and%20figure_v2_clean.pdf Tarling, G.A. orcid:0000-0002-3753-5899 Hobbs, C.; Johnson, M.L.; Färber Lorda, J. 2020 Comparative morphology of Southern Ocean Euphausia species: ecological significance of sexual dimorphic features. Polar Biology, 43. 2043-2058. https://doi.org/10.1007/s00300-020-02764-6 <https://doi.org/10.1007/s00300-020-02764-6> |
op_doi |
https://doi.org/10.1007/s00300-020-02764-6 |
container_title |
Polar Biology |
container_volume |
43 |
container_issue |
12 |
container_start_page |
2043 |
op_container_end_page |
2058 |
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1790599889495785472 |