Distribution of six major copepod species around South Georgia in early summer

Atkinson, Angus. 1989 Distribution of six major copepod species around South Georgia in early summer. Polar Biology, 9 (6). 353-363. 10.1007/BF00442525

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Official URL: http://dx.doi.org/10.1007/BF00442525

Abstract/Summary

An intensive net sampling survey was conducted around the island of South Georgia during November/December 1981. The distribution and copepodite stage structure of the dominant copepods Calanoides acutus, Calanus simillimus, C. propinquus, Rhincalanus gigas, Metridia lucens and Metridia gerlachei were compared. The herbivorous species had completed their spring vertical migration and their summer generations were developing during the survey. At every station, Calanoides acutus was noticeably more advanced than Rhincalanus gigas in its reproductive cycle. The species were also more advanced in their development in the SE oceanic part of the survey area than in the NW. However, copepod development rates are rapid at this time of year, and this apparent regional difference may be due mainly to temporal variation during the four weeks of the survey. A truly regional variation in timing of reproduction was found when development was compared between shelf and oceanic waters. Spawning of Rhincalanus gigas and particularly of Calanoides acutus was later over the shelf. The age structure of the epi-mesopelagic metridinids also differed between shelf and oceanic waters, but no age differences were found for either Calanus simillimus or C. propinquus, both of which live and spawn higher in the water column than the other species. The presence of the South Georgia shelf also limited the overall abundance of the two deeper living metridinids. However, the length of time between spawning (and production of large numbers of early copepodids) and sampling had the largest influence on observed species abundance within the survey area.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1007/BF00442525
ISSN:	0722-4060
Additional Keywords:	oceanic water, reproductive cycle, vertical migration, survey area, herbivorous species
Date made live:	13 Sep 2018 08:08 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/520960

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1007/BF00442525

ISSN:

0722-4060

Additional Keywords:

oceanic water, reproductive cycle, vertical migration, survey area, herbivorous species

Date made live:

13 Sep 2018 08:08 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/520960