Lipid content in the early life stages of three mesopelagic fishes

Changes in lipid concentration during early ontogenetic stages were determined in three mesopelagic fish species, Benthosema glaciale , Hygophum benoiti and Maurolicus muelleri . Total lipid content per larva was related to size and mass and increased over the course of development. In all three species, the dry mass : total lipid ratio displayed a better fit than the standard length : total lipid ratio. Larvae of B. glaciale had a higher amount of lipid content, at a given mass, than the other two species. The rate of lipid accumulation with increasing larval development was similar in B. glaciale and H. benoiti , and both were higher than in M. muelleri larvae. Furthermore, total lipid concentration values, as a proportion of dry mass, increased significantly from the larval to the juvenile stages in B. glaciale (from 16 to 55%) and M. muelleri (from 9 to 20%). The present study has allowed comparisons to be drawn of the ability on the early developmental stages of deep‐sea fishes to accumulate energy reserves, both within and among species.