Diet and feeding strategies of myctophids in the Northeast Atlantic

The trophic ecology of myctophids was investigated during spring 2019 in a large geographical span in the Northeast Atlantic (from Cape Verde to northern France), covering oligotrophic open ocean waters off south Iberia to the productive coastal areas of western Morocco. A total of 417 stomachs from 22 different myctophid species were analysed. Myctophids from the southern areas (from 20 to 42°N) mostly fed on copepods, whereas amphipods were the main prey of myctophids collected in the northern stations (from 42 to 48°N). The calanoids Pleuromamma spp. and Candacia spp., amphipods, euphausiids and decapod larvae were the most positively selected prey by all myctophid species, whenever these prey were present. Pleuromamma spp. were the most important prey for most species, with the largest average contribution to dietary carbon (49.6 ± 21.1%), while Candacia spp. were the dominant prey of Lampanyctus ater (contributing to 40.3% of the estimated dietary carbon), and amphipods were the dominant prey for Hygophum benoiti (39.0%), Myctophum punctatum (58.4%) and Symbolophorus veranyi (56.0%).

Results of the present study indicate that myctophids in the Northeast Atlantic are mainly characterized by specialized feeding strategies, although some species showed mixed strategies (Ceratoscopelus warmingii, Lepidophanes gaussi, Lobianchia dofleini and Lobianchia gemellarii) and a few species (Hygophum hygomii, H. benoiti and S. veranyi) showed a generalized feeding strategy. Our data provide key knowledge for food web and ecosystem studies and contribute to determining the trophodynamics of the global mesopelagic fish community.