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

Abstract

Decapod crustacean fisheries play a crucial role in the Northwestern Mediterranean coast due to their high commercial interest. Yet, larval ecology and recruitment of the species are still little known, although this information is essential to set sustainable fisheries management. In this paper, we describe the larval composition, abundance and distribution of decapod crustaceans in the submarine canyon off Blanes (Northwestern Mediterranean Sea). Samples were collected in September 2011 with a multi-net system and a 60 cm-bongo net (mesh size: 300 ¿m) in 22 stations with bottom depths between 100 and 1800 m, and preserved in 5% formaldehyde. Decapod larvae were sorted and identified to the lowest possible taxonomical level. A total of 470 larvae from 26 genera were found. Gennadas spp. showed the highest average density (7.93 individuals·1000 m-3), followed by Sergestes spp. (7.24) and Alpheus glaber (6.78). These three taxa were dominant (> 20% of total decapod larvae) in more than half of the stations. Total decapod larval density and Shannon diversity index values were significantly higher in the canyon head than in the upstream wall