ALBERT

Description:    The commercially and ecologically valuable sandeel (Ammodytes ssp.) make distinct vertical shifts between an inactive stage, during which they seek refuge in the sand, and a pelagic schooling stage, during which they forage. This characteristic discontinuous foraging pattern constitutes a challenge to fishery biologists and has consequences for a wide range of predators ranging from birds and mammals to commercially important species. However, experimental studies that shed light on the primary drivers of foraging activity in fish are rare. In the present study, whole schools of sandeel ( A . tobianus ) were caught in August in east Denmark (65°02′30N; 12°37′00E) and kept in large tanks in the laboratory. It was found that the amount of food ingested and memory of past days feeding history are primary drivers of foraging activity at the level of the entire school, whereas external factors such as prey concentration and temperature are merely secondary drivers. Content Type Journal Article Pages 1-9 DOI 10.1007/s00227-011-1691-x Authors Mikael van Deurs, National Institute of Aquatic Resources, Technical University of Denmark, Jaegersborg Alle 1, Charlottenlund Castle, 2920 Charlottenlund, Denmark Jane W. Behrens, National Institute of Aquatic Resources, Technical University of Denmark, Jaegersborg Alle 1, Charlottenlund Castle, 2920 Charlottenlund, Denmark Thomas Warnar, National Institute of Aquatic Resources, Technical University of Denmark, Jaegersborg Alle 1, Charlottenlund Castle, 2920 Charlottenlund, Denmark John Fleng Steffensen, Marine Biological Laboratory, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark Journal Marine Biology Online ISSN 1432-1793 Print ISSN 0025-3162