Forage fauna in the diet of three large pelagic fishes (lancetfish, swordfish and yellowfin tuna) in the western equatorial Indian Ocean

Description of diet of pelagic fish in the southwestern Atlantic, Brazil

“…Potier et al (2007) emphasize tuna and similar fish predation to be described as an opportunistic process, as such fishes live in environments containing a relatively low organism's concentration, as are usually known the pelagic ocean regions. Besides the relative homogeneity of such environments, pelagic species may present relative ecological defined niches, which may minimize competition for resources.…”

“…Dragovich (1971), Perrin et al (1973), Pelczarski (1988) and Potier et al (2007) state that the squids Ommastrephidae represent the most important cephalopods present in the diet composition of T. albacares. Other groups, such as Octopoda are also related as food to this tuna fish, though in a relatively small amount.…”

“…1 Letelier et al 2009). Meanwhile, studies made for the Mediterranean Sea (Relini et al 1995), at the northeast Atlantic (Chancollon et al 2006) and at the Indic Ocean (Marsac & Potier 2001, Potier et al 2007) show a precisely converse pattern, thus classifying the swordfish as a primarily ictiophagic predator. The X. gladius diet may vary consistently at distinct habitats and seasons, as a consequence of the variations of the distinct prey population dynamics (Letelier et al 2009).…”

“…As it is known to be an opportunistic predator, the swordfish uses to show a broad alimentary spectrum, feeding on cephalopods, fish and crustaceans (Clarke et al 1995, Figueiredo & Menezes 2000. Its diet composition has been studied in the Mediterranean Sea (Bello 1991);Pacific Ocean (Ibañez et al 2004, Castillo et al 2007, Letelier et al 2009); at the Indic Ocean (Potier et al 2007) and the Atlantic Ocean (Stillwell & Kohler 1985Simões & Andrade 2000, Satoh et al 2004, Chancollon et al 2006. For Brazilian waters, besides the studies of Zavala-Camin (1981), Mello (1992) and Vaske-Júnior (2000), few other studies are registered.…”

Mesoscale eddies influence distribution and aggregation patterns of micronekton in the Mozambique Channel

“…Our findings provide first evidence that mesoscale eddies can shape the aggregation patterns of the prey of top pelagic predators in this region. Indeed, large fish predators such as tuna feed on various micronektonic organisms ranging from 2 to a few 10s of cm, including numerous fish, squid and crustacean species (Young et al 2001, Ménard et al 2006, Potier et al 2007). Piscivorous predators hunt individual prey but commonly seek out micronekton aggregations, such as shoals and clusters of shoals, in the water column (LebourgesDhaussy et al 2000, Bertrand et al 2002.…”