Abstract
The feeding ecology of juvenile (<13,5 cm total length TL), immature (13,6–22,5 cm TL) and adult (>2,6 cm TL) chub mackerel Scomber japonicus was studied off the Canary Islands between March 1988 and May 1989. Copepods were numerically the most abundant prey item, but in terms of mass, mysids were dominant. Diets differ between fish from the Canary Islands and those from the North-West African shelf, which feed mainly on euphausiids. Two shifts in diet occurred with age. Juveniles consumed copepods, appendicularians and small fish, immature fish fed on mysids and copepods, and adults ate a greater proportion of fish.