title: Consistent size-independent harvest selection on fish body shape in two recreationally exploited marine species.
abstract: Harvesting wild animals may exert size-independent selection pressures on a range of morphological, life history, and behavioral traits. Most work so far has focused on selection pressures on life history traits and body size as morphological trait. We studied here how recreational fishing selects for morphological traits related to body shape, which may correlate with underlying swimming behavior. Using landmark-based geometric morphometrics, we found consistent recreational fishing-induced selection pressures on body shape in two recreationally exploited marine fish species. We show that individuals with larger-sized mouths and more streamlined and elongated bodies were more vulnerable to passively operated hook-and-line fishing independent of the individual's body size or condition. While the greater vulnerability of individuals with larger mouth gapes can be explained by the direct physical interaction with hooks, selection against streamlined and elongated individuals could either involve a specific foraging mode or relate to underlying elevated swimming behavior. Harvesting using passive gear is common around the globe, and thus, size-independent selection on body shape is expected to be widespread potentially leaving behind individuals with smaller oral gapes and more compact bodies. This might have repercussions for food webs by altering foraging and predation.
authors.affiliation: Instituto Mediterráneo de Estudios Avanzados, IMEDEA (CSIC-UIB) C/Miquel Marqués 21, 07190, Esporles, Illes Balears, Spain ; Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries Müggelseedamm 310, 12587, Berlin, Germany.
authors.forename: Josep
authors.initials: J
authors.lastname: Alós
authors.affiliation: Instituto Mediterráneo de Estudios Avanzados, IMEDEA (CSIC-UIB) C/Miquel Marqués 21, 07190, Esporles, Illes Balears, Spain.
authors.forename: Miquel
authors.initials: M
authors.lastname: Palmer
authors.affiliation: Faculty of Life Sciences, University of Manchester M13 9PT Manchester, U.K.
authors.forename: Marta
authors.initials: M
authors.lastname: Linde-Medina
authors.affiliation: Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries Müggelseedamm 310, 12587, Berlin, Germany ; Chair of Integrative Fisheries Management and Integrative Research Institute for the Transformation of Human-Environment Systems (IRI THESys), Faculty of Life Sciences, Humboldt-Universität zu Berlin Invalidenstrasse 42, 10115, Berlin, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Arlinghaus
keywords: Behavior; ecomorphology; fisheries-induced selection; geometric morphometrics; predator–prey interactions; recreational fishing