Migratory patterns, vertical distributions and diets of Abralia veranyi and Abraliopsis morisii (Cephalopoda: Enoploteuthidae) in the eastern North Atlantic

Abstract

Abralia veranyi and Abraliopsis morisii were the most abundant cephalopods caught during epipelagic and mesopelagic surveys off the Canary Islands and accounted for 26% and 35% of the cephalopod catch, respectively. Diel vertical migration patterns were observed in both species. At night, A. veranyi was recorded at depths as shallow as 38-90 m, whereas Abraliopsis morisii occurred at depths of 98-219 m. As individuals grow in mantle length, their diet changes substantially. Abraliopsis morisii showed ontogenetic shifts at 22.9 mm and 35.3 mm dorsal mantle length (DML), while A. veranyi showed ontogenetic shifts at 20.5 mm and 30.9 mm DML. Prior to the first ontogenic shift, both species fed mainly on copepods and mysids. After this shift they fed on larger prey, such as decapods and fish; the diets of larger individuals also contained cephalopods.