Patricio Barría

Preliminary diet analysis of the blue shark Prionace glauca in the eastern South Pacific

The diet of the blue shark Prionace glauca off central and northern Chile in the eastern South Pacific, during 2005 and 2006 were dominated by teleost fishes (72.21 %IRI) and cephalopods (27.07 %IRI). The seasonal feeding of blue shark showed as the most important prey diverse teleost fish species. Our findings would confirm that blue shark is a predator with wide trophic spectrum in the eastern south Pacific, although a higher number of stomachs need to be studied.

Alimentación y relaciones tróficas del pez espada (Xiphias gladius Linnaeus, 1758), frente a Chile centro-norte durante 2005

A total of 126 sword-fish (Xiphias gladius) stomach were analyzed. The stomachs were obtained from specimens captured within the 25° to 34°S and 78° to 90°W ...

Alimentación del tiburón marrajo Isurus oxyrinchus Rafinesque, 1810 (Lamniformes: Lamnidae) en el Pacífico suroriental

In order to examine the feeding of mako shark Isurus oxyrinchus, the stomach content of 205 specimens, captured between 21o and 35oS and 78o and 118o W off C...

New insights on the trophic ecology of blue (Prionace glauca) and shortfin mako sharks (Isurus oxyrinchus) from the oceanic eastern South Pacific

ABSTRACT The blue shark (Prionace glauca) and the shortfin mako shark (Isurus oxyrinchus) are two large and highly migratory sharks distributed in most oceans. Although they are often caught in the south Pacific Ocean long-line fisheries, their trophic ecology is poorly understood. Stable isotopes with Bayesian mixing and dependence concentration models were performed to determine the diet and trophic differences between the two species in the South-eastern Pacific Ocean. According to the mixing models, fishes are the most important prey of these sharks. Dolphin calves and remains were found in the stomachs of both species, which represents a novel finding in trophic ecology of South Pacific sharks. Intra-specific differences were found in P. glauca, but not in specimens of I. oxyrinchus. The two sharks showed a high degree of diet overlap (73%), primarily over mackerel and dolphin carcasses. Our results indicate that blue and shortfin mako sharks have a generalist feeding strategy in the eastern Pacific Ocean, with a strong preference for teleost fishes and also for dolphin carcasses. Therefore, trophic studies are useful to understand energy flow through the food web, and the trophic position of key species.