Ctenophora in the Arctic: the abundance, distribution and predatory impact of the cydippid ctenophore Mertensia ovum (Fabricius) in the Barents Sea

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Swanberg, Neil ; Båmstedt, Ulf (1991)

The Ctenophora Mertensia ovum and Beroe cucumis, collected using both conventional sampling gear and scuba divers, were studied in the Barents Sea east of Bjørnøya and North Norway in spring 1987 and summer 1988. Among the gelatinous zooplankton, Mertensia ovum was the most consistently abundant copepod predator. Feeding experiments were conducted to evaluate the predation rate of M. ovum in various trophic regimes. This ctenophore can take prey varying in size from small copepods to amphipods and krill, but gut-content analyses from field-collected specimens as well as experimental results showed that the main food source for adults was large-sized copepods (e.g. Calanus finmarchicus, C. glacialis, C. hyperboreus, Metridia longa). The robust tentacle arrray of M. ovum makes this species effective as a predator on large prey. The high potential predation rate of this ctenophore relative to its estimated metabolic cost of only 1.7% of the body energy content d?1 suggests that M. ovum may be able to maintain a positive energy balance even in conditions of low prey abundance. It is suggested that a single exploitation of a zooplankton patch may provide energy for survival for a very long time. The potential impact of M. ovum on Barents Sea copepod populations is estimated on the basis of the minimal observed average daily ration in experiments and from field data on gut contents. Using abundances of copepods for the area, and the actual predator biomass collected, it was estimated that an average of 0.7% of the copepod fauna per day could fall prey to this predator.
  • References (36)
    36 references, page 1 of 4

    Alldredge. A. 1972: Abandoned larvacean houses: A unique food source in the pelagic environment. Science 177,885887, Anderson, E. 1974: Trophic interactions among ctenophores and copepods in St. Margaret's Bay, Nova Scotia. Ph.D. Thesis. Sept.. 1974. Dalhousie Univ. 85 pp.

    Biggs. D. C.. Bidigare. R. R. & Smith. D. E. 1981: Population density of gelatinous macrozooplankton: I n situ estimation in oceanic surface waters. Biol. Oceanog. I . 157-173.

    Blggs. D. C . . Laval. P.. Braconnot, J - C . , Carri, C.. Goy. J . . Masson. M. & Morand. P. 1987: In situ observations of Mediterranean zooplankton by SCUBA and bathyscaphe in the Ligurian Sea in Apnl 1986. Pp. 153-161 i n : “Diving for Science...86.“ Proceedings of the Sixth Annual Scientific Diving Symposium. 31 Oct-3 Nov.. 1986, Tallahassee, Florida. American Academy of Underwater Sciences.

    BBmstedt, U. 1981: Water and organic content of boreal macrozooplankton and their significance for the energy content. Sarsia 66. 59-66

    Deason. E. E. & Smayda. T. J. 1982:Ctenophore-zooplanktonphytoplankton interactions in Narragansett Bay, Rhode Island. U.S.A., during 1972-1977. J . Plankton Res. 4, 203-217.

    De Lafontaine, Y. & Legget, W. C. 1987: Effect of container size on estimates of mortality and predation rates in experiments with macrozooplankton and larval fish. Can. J. Fish. Aq. Sci. 44, 1534-1543.

    Elliot, J . M. & Davison. W. 1975: Energy equivalents of oxygen consumption in animal energetics. Oecologica (Eerl.) 19. 19S201.

    Feigenbaum. D. & Reeve, M. R . 1977: Prey detection in the Chaetognatha: Response to a vibrating probe and experimental determination of attack distance in large aquaria. Limnol. Oceanogr. 22, 1052-1058.

    Fraser, J. H. 1970:The ecology of the ctenophore Pleurobrachia pileus in Scottish waters. 1. Cons. Int. Explor. Mer 33, 149-168.

    Greene, C. H. 1986: Patterns of prey selection: implications of predator foraging tactics. A m . Naturalist 128, 824-839.

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