MEPS 299:1-5 (2005)  -  doi:10.3354/meps299001

Piscivorous fish patrol krill swarms

Stein Kaartvedt1,*, Anders Røstad1, Øyvind Fiksen2, Webjørn Melle3, Thomas Torgersen2, Mari Tiseth Breien3, Thor A. Klevjer1

1Department of Biology, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norway
2Department of Biology, University of Bergen, PO Box 7800, 5020 Bergen, Norway
3Institute of Marine Research, PO Box 1870, 5817 Bergen, Norway

ABSTRACT: Dense swarms of the krill Meganyctiphanes norvegica in the Norwegian Sea were patrolled by large, piscivorous fish, which apparently use the krill swarms as feeding grounds in their hunt for planktivores. For the krill, patrols of piscivores may add to the generally accepted anti-predator benefit of the swarming behavior. The fact that krill swarms govern small-scale patchiness of large piscivores emphasizes the key role of krill in oceanic ecosystems.


KEY WORDS: Swarms · Fish · Anti-predator benefits · Behavioral cascades · Meganyctiphanes norvegica


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