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Hokkaido University Collection of Scholarly and Academic Papers >
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Chemical composition and energy content of deep-sea calanoid copepods in the Western North Pacific Ocean
| Title: | Chemical composition and energy content of deep-sea calanoid copepods in the Western North Pacific Ocean |
| Authors: | Ikeda, Tsutomu Browse this author →KAKEN DB | | Yamaguchi, Atsushi Browse this author →KAKEN DB | | Matsuishi, Takashi Browse this author →KAKEN DB |
| Keywords: | Copepods | | Deep-sea | | C and N composition | | Energy | | Condition factor index | | Western North Pacific |
| Issue Date: | Nov-2006 |
| Publisher: | Elsevier Ltd |
| Journal Title: | Deep Sea Research Part I Oceanographic Research Papers |
| Volume: | 53 |
| Issue: | 11 |
| Start Page: | 1791 |
| End Page: | 1809 |
| Publisher DOI: | 10.1016/j.dsr.2006.08.002 |
| Abstract: | Condition factor index [CFI=1000×DW/(PL)3; DW: dry weight, PL: prosome length], water content, carbon (C), nitrogen (N), ash and energy content were determined on a total of 69 copepod species caught from the mesopelagic (500-1000 m), upper-bathypelagic (1000-2000 m), lower-bathypelagic (2000-3000 m) and abyssopelagic (3000-5000 m) zones of the western subarctic Pacific. Resultant data were grouped into these four sampling zones, four developmental stage/sex categories (C4, C5 and C6 females and males), three feeding types (carnivore, detritivore and suspension feeder), or two reaction speed groups by the presence/absence of myelinated sheath enveloping axons (fast and slow reacting species). Zone-structured data showed the overall ranges were 3.8-4.6 mm for PL, 1.6-2.6 mg for DW, 21.4-25.0 for CFI, 75.0-78.6% of wet weight (WW) for water, 51.3-53.7% of DW for C, 7.7-8.8% of DW for N, 6.2-7.0 (by weight) for C/N, 6.9-9.6% of DW for ash and 25.3-27.4 J mg-1 DW for energy. Among these components, N and ash exhibited significant between-zone differences characterized by gradual decrease downward for the former, and only the upper-bathypelagic zone > abyssopelagic zone for the latter. Stage/sex-structured data showed no significant differences among them, but energy content of C5 was higher than that of C6 females. From the analyses of feeding type-structured data, carnivores were shown to have lower water, N, ash, but higher C, C/N and energy contents than suspension feeders do. Reaction speed-structured data indicated that slow-reacting species have significantly higher water but lower CFI, C, N and energy contents than fast-reacting species. Designating these grouping criteria, PL and DW as independent variables, the attributes of these variables to the CFI, chemical composition or energy contents were evaluated by stepwise-multiple regression analysis, showing the most pronounced effect of suspension-feeder, followed by the presence of myelinated sheath, DW, C6 females and the abyssopelagic zone. Further analysis of zone-structured data, by adding epipelagic copepod data from identical thermal habitats (Arctic/Antarctic waters), revealed a more marked decline in N content from the epipelagic zone to the abyssopelagic zone, accompanied by an increase in C/N ratios downward. The decline in N (=protein or muscle) contents with depth cannot be explained by the "visual interactions" hypotheses being proposed for the metabolism of pelagic visual predators, but is consistent with the "predation-mediated selection" hypothesis for the metabolism of pelagic copepods. |
| Relation: | http://www.sciencedirect.com/science/journal/09670637 |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/17174 |
| Appears in Collections: | 水産科学院・水産科学研究院 (Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 池田 勉
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