Utility of storage lipid volumes in inferring recent trophic history of copepods
We were able to estimate lipid oil-sac volumes of Pseudocalanus spp. copepodids c3 to c5 on and around Western Bank, Scotian Shelf, during three cruises (October and November 1997 and January 1998) at stations on (<60 m depth) and off (>60 m depth) the bank. We test the hypothesis that...
| Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
|---|---|
| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1999
|
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/f99-196 http://www.nrcresearchpress.com/doi/pdf/10.1139/f99-196 |
| Summary: | We were able to estimate lipid oil-sac volumes of Pseudocalanus spp. copepodids c3 to c5 on and around Western Bank, Scotian Shelf, during three cruises (October and November 1997 and January 1998) at stations on (<60 m depth) and off (>60 m depth) the bank. We test the hypothesis that storage lipid volume was not significantly different between locations during these three months. Pseudocalanus spp. are an important prey for Atlantic cod (Gadus morhua) larvae that are spawned and persist on the bank. However, in contrast with the greater concentration of Pseudocalanus spp. on relative to off the bank, size-adjusted oil-sac volumes were on average larger and less variable at off-bank stations. We conclude that the greater copepod concentration on the bank does not result from enhanced and uniform nutrition on the bank. Lipid volumes averaged larger in winter than in the autumn, indicating that nutritional condition of Pseudocalanus spp. copepodids does not decline subsequent to the autumn bloom. Although biochemical techniques are available to quantify the level of storage lipids in individual copepods, simple measurements of oil sacs and body sizes permit a rapid real-time assessment of their recent trophic history in relation to oceanographic structure. |
|---|