Krause J. auteur aut IRD Herbert-Read J. E. auteur aut IRD Seebacher F. auteur aut IRD Domenici P. auteur aut IRD Wilson A. D. M. auteur aut IRD Marras S. auteur aut IRD Svendsen M. B. S. auteur aut IRD Strombom D. auteur aut IRD Steffensen J. F. auteur aut IRD Krause S. auteur aut IRD Viblanc P. E. auteur aut IRD Couillaud P. auteur aut IRD Bach Pascal auteur aut IRD Sabarros P. S. auteur aut IRD Zaslansky P. auteur aut IRD Kurvers Rhjm auteur aut IRD text journalArticle eng text/pdf born digital access The costs and benefits of group living often depend on the spatial position of individuals within groups and the ability of individuals to occupy preferred positions. For example, models of predation events for moving prey groups predict higher mortality risk for individuals at the periphery and front of groups. We investigated these predictions in sardine (Sardinella aurita) schools under attack from group hunting sailfish (Istiophorus platypterus) in the open ocean. Sailfish approached sardine schools about equally often from the front and rear, but prior to attack there was a chasing period in which sardines attempted to swim away from the predator. Consequently, all sailfish attacks were directed at the rear and peripheral positions of the school, resulting in higher predation risk for individuals at these positions. During attacks, sailfish slash at sardines with their bill causing prey injury including scale removal and tissue damage. Sardines injured in previous attacks were more often found in the rear half of the school than in the front half. Moreover, injured fish had lower tail-beat frequencies and lagged behind uninjured fish. Injuries inflicted by sailfish bills may, therefore, hinder prey swimming speed and drive spatial sorting in prey schools through passive self-assortment. We found only partial support for the theoretical predictions from current predator-prey models, highlighting the importance of incorporating more realistic predator-prey dynamics into these models. This article is part of the themed issue 'Physiological determinants of social behaviour in animals'. specialized group-living fish schools predation spatial positions locomotion MEXIQUE GOLFE 034 372 1727 art. 20160232 [8 p.] 2017 0962-8436 https://www.documentation.ird.fr/hor/fdi:010070319 10.1098/rstb.2016.0232 0962-8436 [F B010070319] https://www.documentation.ird.fr/hor/fdi:010070319 https://www.documentation.ird.fr/intranet/publi/2017/08/010070319.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2017-09-05 2023-07-11 fdi:010070319 fre