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

Abstract

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 m3), 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.

Interannual fluctuations in connectivity among crab populations (Liocarcinus depurator) along the Atlantic-Mediterranean transition

“…The most probable explanation for the occurrence of this pattern would be the presence of the AOF, considered by many authors as the most relevant barrier generating the interruption or reduction of gene flow between populations of different species 54 – 58 . It is worth remarking that the AOF is an epipelagic structure, affecting the upper layers of the pelagic environment, where high concentrations of decapod crustacean larvae are usually reported 59 , 60 . By comparing the annual frequencies of the ATL haplogroup in this area, it was possible to understand the differentiation dynamics between populations.…”

Summer decapod crustacean larval communities along the eastern Spanish Mediterranean coast

“…In line with a smaller-scale study in the area of the submarine canyon off Blanes, our results show the larvae of the deep-sea blue and red shrimp A . antennatus as one of the dominant species in this period of the year [ 20 ]. They were associated to cold, high-salinity waters which would correspond to the old Atlantic water of the Northern zone.…”

“…The challenging and time-consuming task of identifying decapod larvae to species level has limited the study of these communities, so much so that we can only count a few of these studies in the Western Mediterranean Sea [ 12 , 15 – 20 ]. Currently, the descriptions of many decapod crustacean larvae are outdated or do not follow modern standards, and some larval stages of decapod taxa have yet to be found in the plankton or confirmed by molecular methods [ 21 ].…”