Decapod crustacean larval community structure of the submarine canyon off Blanes (NW Mediterranean Sea)

Decapod crustacean fisheries play a crucial role on the northwestern Mediterranean coast due to their high commercial value. Although knowledge of larval ecology and recruitment dynamics of these species is essential to establish a sustainable fisheries management, they are still poorly known. In this paper, we describe the composition, abundance and distribution of decapod crustacean larvae in the submarine canyon off Blanes (northwestern Mediterranean Sea) during summer thermal stratification conditions. Samples were collected in September 2011 with a multi-net system and a 60-cm bongo net at 22 stations with bottom depths of between 100 and 1800 m. A total of 635 larvae from 60 genera were identified. The most relevant taxa were Aristeus antennatus (7.93 individuals/1000 m(3)), the family Sergestidae (7.24) and Alpheus glaber (6.78). These three taxa were dominant (>20% of total decapod larvae) at more than half of the stations. Decapod larval communities were found to be richer and more diverse at the canyon head. a finding which could be explained by the higher retention rates when compared with the upstream and downstream walls and the canyon axis.