Fatty acid patterns and stomach contents of two North Sea squid species, Loligo forbesii and Illex coindetii - [dataset]

With increasing temperatures in the North Sea, the local squid biomass has increased and new species have started to successfully reproduce in this area. One of these new species is the broadtail shortfin squid Illex coindetii. The squid with the so far highest biomass in the North Sea is Loligo forbesii. We selected the fatty acid (FA) composition and analyzed the stomach contents to obtain information about the prey spectra of these species. Individuals of both species were caught in July and August 2023. A total of 27 I. coindetii and 14 L. forbesii were measured for the FA composition of the mantle tissue and digestive glands (DG) as well as their stomach contents. In both species, the DG contained a higher variety and a higher content of FAs than the mantle. The FA compositions of the DG suggest moderate overlap in prey spectra of I. coindetii and L. forbesii. The stomach contents of both squid species showed a high degree of dietary overlap and contained several commercially important species As the North Sea temperatures keep rising, squids are expected to play a more important role in the regional food webs, and squids are targeted as a valuable fishery resource in the North Sea.