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Marine Biology

, Volume 136, Issue 1, pp 129–135 | Cite as

Contribution of heterotrophic material to diet and energy budget of Antarctic krill, Euphausia superba

  • R. Perissinotto
  • L. Gurney
  • E. A. Pakhomov
Article

Abstract

A novel approach was used to estimate the heterotrophic carbon component in the diet of the Antarctic krill Euphausia superba. Over 200 specimens from seven samples collected in the Lazarev Sea (January 1993 and 1995), at the Antarctic Polar Front (January 1993), and around South Georgia (February/March 1994) were dissected, and the total carbon content of their stomachs was estimated with a CHN-analyser. Gut-pigment contents were also measured by the gut-fluorescence technique in specimens collected at the same time, and the equivalent amount of their gut carbon was then subtracted from the total organic carbon content of guts from the same samples. The remaining carbon was assumed to originate entirely from heterotrophic food sources. This heterotrophic component accounted for a substantial proportion of the total food consumed by Antarctic krill, ranging from 17.4 to 98.9% of the mass of the gut contents (mean = 78.8% ± 21.2 SD). The results make an important contribution to the elucidation of the energy budget of krill and its daily carbon ration. With a few exceptions, previous estimates were largely calculated from a solely autotrophic carbon source, and were unable to account for the metabolic requirements of E. superba. Krill plays an important role in Antarctic food webs, as it often constitutes ≃50% of the total biomass of the zooplankton, and produces fast-sinking, dense faecal pellets which are important in the vertical transport of organic carbon from the euphotic layer to the deep ocean. High consumption rates of smaller heterotrophic organisms by krill suggest that this large microphage may be more important than previously believed in re-packaging micro- and mesozooplankton into a longer-lasting and more easily sequestered carbon pool.

Keywords

Total Organic Carbon Total Organic Carbon Content Antarctic Krill Total Carbon Content Euphotic Layer 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • R. Perissinotto
    • 1
  • L. Gurney
    • 2
  • E. A. Pakhomov
    • 2
  1. 1.Marine Science Unit, University of Durban-Westville, Private Bag X54001, Durban 4000, South Africa Fax: 0027 (0)31-2044730 e-mail: renzo@pixie.udw.ac.zaZA
  2. 2.Southern Ocean Group, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown 6140, South AfricaZA

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