TY - JOUR AU - Ménard Frédéric, Potier Michel PY - 2013// TI - Pelagic cephalopods in the western Indian Ocean: New information from diets of top predators T2 - Deep Sea Res. Part II Top. Stud. Oceanogr. JO - DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY SP - 83 EP - 92 VL - 95 KW - Beaks KW - Diet composition KW - Octopod KW - Ommastrephidae KW - Pelagic fish KW - Sooty tern KW - Squid KW - Trophic ecology KW - N2 - Using a combination of diverse large predatory fishes and one seabird, we collected information on the cephalopod fauna of the western Indian Ocean. We analyzed the stomach contents of 35 fishes representing ten families (Xiphiidae, Istiophoridae, Scombridae, Carangidae, Coryphaenidae, Alepisauridae, Dasyatidae, Carcharhinidae, Alopiidae and Sphyrnidae) and of the sooty tern Onychoprion fuscata of the Mozambique Channel from 2000 to 2010. Both fresh and accumulated beaks were used for identifying cephalopod prey. Cephalopods were important prey for twelve predators; swordfish Xiphias gladius had the highest cephalopod proportion; sooty tern (O. fuscata) and bigeye tuna (Thunnus obesus) had high proportions too. We recovered 23 cephalopod families and identified 38 species. Ten species from four Teuthida families (Ommastrephidae, Onychoteuthidae, Histioteuthidae and Ancistrocheiridae) and two Octopoda families (Argonautidae and Bolitaenidae) occurred very frequently in the stomach contents, while Sepiida were rare. Ommastrephidae were the most cephalopod food sources: the purpleback flying squid Sthenoteuthis oualaniensis was the most prevalent prey by far, Ornithoteuthis volatilis was important for eleven predators and few but large specimens of the neon flying squid Ommastrephes bartramii were recovered in the stomachs of swordfish in the Indian South Subtropical Gyre province only. Predators' groups were identified based on cephalopod prey composition, on depth in which they forage, and on prey size. Surface predators' diets were characterized by lower cephalopod diversity but greater average numbers of cephalopod prey, whereas the deep-dwelling predators (swordfish and bigeye tuna) preyed on larger specimens than surface predators (O. fuscata or yellowfin tunas Thunnus albacares). Our findings emphasized the usefulness of a community of marine predators to gain valuable information on the biology and the distribution of the cephalopod forage fauna that are discussed with regard to biogeographic province, marine predator, fishing gear to catch the large pelagic fishes, and size of the beaks recovered in the stomachs. SN - 0967-0645 UR - http://dx.doi.org/10.1016/j.dsr2.2012.08.022 N1 - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=4410), last updated on Sun, 21 Jul 2024 10:24:41 +0200 ID - MenardFrederic2013 ER -