Article
Trophodynamics of the jumbo squid Dosidicus gigas during winter in the Southeast Pacific Ocean off the coast of Chile: Diet analyses and fatty acid profile
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0165-7836
Autor
Quispe-Machaca, Marco
Guzmán-Rivas, Fabián A.
Ibáñez, Christian M.
Urzúa, Ángel
Resumen
Artículo de publicación WOS - SCOPUS Marine trophodynamic studies have been developed mainly through the evaluation of stomach contents. How-
ever, these studies only reflect the feeding of a few days, showing a "snapshot" of the food consumed for a short
time. Currently, new complementary techniques have been developed to evaluate the diet of predators using
biochemical markers (fatty acids, FAs) and can, in turn, consider the rate of renewal of these biochemical
constituents in body tissues. In the jumbo squid Dosidicus gigas, an important fishery resource in the Humboldt
Current System, we identified and analyzed the stomach contents (prey) of D. gigas collected along the coasts of
Chile in order to compare the FA profiles of its prey with those of three of its principal tissues and/or organs
(digestive gland, gonad and mantle muscle). The analyses of the stomach contents indicate that D. gigas feeds on
fish, crustaceans and squids, as previously have been reported. Regarding the FAs, the digestive gland presented
the highest concentration and diversity of FAs, followed by the gonad and then the mantle. In turn, when
comparing the FAs of the digestive gland of D. gigas with the FA profiles of its preys, the crustacean Pleuroncodes
monodon and the fish Lampanyctus sp. presented the closest similarity, especially with a high contribution of
essential FAs and PUFAs. Our findings indicate that during the cold season (austral winter), individuals of D. gigas
may present an energy optimization strategy, characterized by the intake of prey with a high energy content rich
in PUFAs, such as crustaceans and small fishes. This study not only contributes to the understanding of the squid
biology and their trophodynamic, but also has important implications to improve fishery management within an
ecosystem approach. This is relevant because D. gigas and its prey have suffered heavy exploitation, with a
significant reduction in their biomass.