Abstract

The trophic ecology of squids has been studied using traditional methods of stomach content identification, there are reports of the diet of species of the order Oegopsida that described the prey and consumption of these predators in oceanic waters. Recently, the trophic ecology studies have included the analysis of hard tissues and the δ¹³C and δ¹⁵N to identify changes in the contribution of prey to the diet of squids, and to describe the trophic niche and overlap probability between species. This review analyzed the bibliographic references that used beaks and gladii to understand the trophic ecology of squids that inhabit in the marine waters of America. Results demonstrate that the beak of 14 oegopsid squid families have been included in this kind of analysis. The most studied squid was the Ommastrephid Dosidicus gigas in the Pacific Ocean, but many squid families (13) were analyzed in the Atlantic Ocean. The gladius was included in the hard tissue analysis, and it was reported that in addition to beaks, they are useful to describe the habitat, use of prey for squids, and feeding changes through ontogeny. As squids are fast moving predators, the use of these tissues in the isotope analysis help researchers to identify hot spots in the ocean, because these areas are the main refuges for feeding and for the development of these populations. Sympatric species can be identified by using hard tissue and isotopic analysis, as these tissues recorded the use of habitat and feeding behavior.

Keywords: Isotopes; Oegopsid squids; Trophic niche; Trophic ecology; American oceans