Abstract
Length–mass relationships and linear regressions are given for otolith size (length and height) and standard length ( L S ) of certain mesopelagic fishes (Myctophidae, Paralepididae, Phosichthyidae and Stomiidae) living in the central Mediterranean Sea. The length–mass relationship showed isometric growth in six species, whereas linear regressions of L S and otolith size fit the data well for all species. These equations represent a useful tool for dietary studies on Mediterranean marine predators.