Effects of body size, age and maturity stage on diet in a large shark: ecological and applied implications

摘要: Ontogenetic diet shifts are a widespread phenomenon among vertebrates, although their relationships with life history traits poorly known. We analyzed the relative importance of body size, age and maturity stage as determinants marine top predator, copper shark, Carcharhinus brachyurus, by examining stomach contents using multiple-hypothesis modeling approach. Copper sharks shifted size increased they became sexually mature, incorporated larger prey grew, had discrete shift in only individuals than ≈200 cm total length able to on chondrichthyans. Body was most important trait explaining consumption chondrichthyans, while determined pelagic teleosts. Pelagic teleosts were consumed mostly medium-aged sharks, result, probably, risk-reducing feeding strategy at young ages coupled either senescence-related decline performance or change sensory capabilities age. all sizes cut pieces, implying that gape limitation (i.e., impossibility eating predator’s mouth) did not play role producing shift. Our results suggest that, contrary current practice setting minimum but maximum limits catches, any plan conserve restore ecological function through predatory control large prey, should aim maintain largest individuals.