Distribution and biology of Alepocephalus rostvatus from the Mediterranean Sea

In the Catalan Sea (NW Mediterranean) A. rostratus was found on the bottom below 500 m and reached its maximum abundance and biomass at 1100–1300 m depth, being captured down to 2209 m. Mean fish size increased progressively with depth. Larger fish were predominantly females, and 50% of maturity was reached at 23–6 and 27–7 cm in males and females, respectively. Although a high percentage of the population was mature all year round, a peak was attained in autumn, coinciding with the slowest growth of the species. Size-at-age indicated a slow growth rate. The greatest observed age was 23 years, although most of individuals were 7–12 years old. Overall, A. rostratus can be considered as a typical K-strategist, showing a good adaptation to the oligotropic deepsea environment.