How sailfish use their bills to capture schooling prey.
The istiophorid family of billfishes is characterized by an extended rostrum or 'bill'. While various functions (e.g. foraging and hydrodynamic benefits) have been proposed for this structure, until now no study has directly investigated the mechanisms by which billfishes use their rostrum to feed on prey. Here, we present the first unequivocal evidence of how the bill is used by Atlantic sailfish (Istiophorus albicans) to attack schooling sardines in the open ocean. Using high-speed video-analysis, we show that (i) sailfish manage to insert their bill into sardine schools without eliciting an evasive response and (ii) subsequently use their bill to either tap on individual prey targets or to slash through the school with powerful lateral motions characterized by one of the highest accelerations ever recorded in an aquatic vertebrate. Our results demonstrate that the combination of stealth and rapid motion make the sailfish bill an extremely effective feeding adaptation for capturing schooling prey.
IAMC-CNR, Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, , Località Sa Mardini, 09170 Torregrande, Oristano, Italy, Department of Biology and Ecology of Fishes, Leibniz Institute of Freshwater Ecology and Inland Fisheries, , Mueggelseedamm 310, 12587 Berlin, Germany, Department of Mathematics, University of Uppsala, , Uppsala, Sweden, Department of Ecology and Genetics, University of Uppsala, , Uppsala, Sweden, Marine Biological Section, University of Copenhagen, Strandpromenaden 5, , 3000 Helsingør, Denmark, Department of Electrical Engineering and Computer Science, Lübeck University of Applied Sciences, , 23562 Lübeck, Germany, Faculty of Life Sciences, Humboldt-Universität zu Berlin, , Invalidenstrasse 42, 10115 Berlin, Germany, Département de la Licence Sciences et Technologies, Université Pierre et Marie Curie, , 4 place Jussieu, 75005 Paris, France, Department of Biology, Carleton University, , 1125 Colonel By Drive, Ottawa, Ontario, Canada.
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Domenici
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Wilson
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Kurvers
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Marras
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Herbert-Read
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Steffensen
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Krause
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Viblanc
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Couillaud
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Krause
D000054:Acceleration; D000220:Adaptation, Biological; D000818:Animals; D010473:Perciformes / Q000033:anatomy & histology / Q000502:physiology*; D011235:Predatory Behavior; D014743:Videotape Recording
animal weapons; billfishes; fish schools; predator–prey interactions