An experimental aquarium for observing the schooling behaviour of Antarctic krill (Euphausia superba)

• Published in: Deep Sea Research Part II: Topical Studies in Oceanography
• Main Authors: Kawaguchi, S, King, R, Meijers, R, Osborn, JE, Swadling, KM, Ritz, DA, Nicol, S
• Format: Article in Journal/Newspaper
• Language: English
• Published: Pergamon-Elsevier Science Ltd 2010
• Subjects: Environmental Sciences; Environmental Science and Management; Wildlife and Habitat Management; Antarctic; Antarc*; Antarctic Krill; Euphausia superba
• Online Access: http://www.sciencedirect.com; https://doi.org/10.1016/j.dsr2.2009.10.017; http://ecite.utas.edu.au/65693

Schooling behaviour of Antarctic krill was induced repeatedly over a period of one year in the AustralianAntarctic Division research aquarium. The details of the laboratory setup suitable for krill to school aredescribed. Light intensity and food condition were found to affect krill swimming patterns andschooling behaviour. Krill swam in polarised groups and responded as a group to objects that producedsharp contrasts but not to less distinct objects. Schools broke up when they encountered densephytoplankton patches, and aggregated more tightly when kept with a white featureless background.The diel nature of school formation was observed under simulated natural light conditions withstronger and tighter schools during daytime and no obvious schooling behaviour during night. Thesebehavioural patterns are further discussed in terms of their costs and benefits of feeding and predationrisk, in conjunction with the diel vertical migration behaviour of krill.