title: Feeding ecology of silky sharks Carcharhinus falciformis associated with floating objects in the western Indian Ocean.
abstract: The silky shark Carcharhinus falciformis is commonly associated with floating objects, including fish aggregating devices (FADs), in the Indian Ocean. While the motives for this associative behaviour are unclear, it does make them vulnerable to capture in the tuna purse seine fishery that makes extensive use of FADs. Here, the diet of 323 C. falciformis, caught at FADs in the Indian Ocean, was investigated to test the hypothesis that trophic benefits explain the associative behaviour. A high proportion of stomachs with fresh contents (57%) suggested that extensive feeding activity occurred while associated with FADs. Multiple dietary indices showed that typical non-associative prey types dominated, but were supplemented with fishes typically found at FADs. While the trophic benefits of FAD association may be substantial, our results suggest that associative behaviour is not driven solely by feeding.
authors.affiliation: South African Institute for Aquatic Biodiversity, Grahamstown, 6140, South Africa.|Department of Ichthyology and Fisheries Science, Rhodes University, Grahamstown, 6140, South Africa.|Institut de Recherche pour le Développement, UMR MARBEC (IRD, Ifremer Univ. Montpellier, CNRS), Avenue Jean Monnet CS 30171, 34203, Sète cedex, France.
authors.forename: J D
authors.initials: JD
authors.lastname: Filmalter
authors.affiliation: South African Institute for Aquatic Biodiversity, Grahamstown, 6140, South Africa.
authors.forename: P D
authors.initials: PD
authors.lastname: Cowley
authors.affiliation: Institut de Recherche pour le Développement, UMR MARBEC (IRD, Ifremer Univ. Montpellier, CNRS), Avenue Jean Monnet CS 30171, 34203, Sète cedex, France.
authors.forename: M
authors.initials: M
authors.lastname: Potier
authors.affiliation: Aix Marseille Université, Université Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), Marseille, France.
authors.forename: F
authors.initials: F
authors.lastname: Ménard
authors.affiliation: Port Elizabeth Museum at Bayworld, Port Elizabeth, Eastern Cape, South Africa.|Department of Zoology, CMR, Nelson Mandela Metropolitan University, P. O. Box 77000, Port Elizabeth, Eastern Cape, South Africa.
authors.forename: M J
authors.initials: MJ
authors.lastname: Smale
authors.affiliation: Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-Université de La Rochelle, 79360, Villiers-en-Bois, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Cherel
authors.affiliation: Institut de Recherche pour le Développement, UMR MARBEC (IRD, Ifremer Univ. Montpellier, CNRS), Avenue Jean Monnet CS 30171, 34203, Sète cedex, France.
authors.forename: L
authors.initials: L
authors.lastname: Dagorn
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources; D004784:Environmental Monitoring; D005247:Feeding Behavior / Q000502:physiology*; D019156:Indian Ocean; D012754:Sharks / Q000502:physiology*; D014413:Tuna
keywords: FAD; by-catch; diet; fish aggregation device; pelagic shark