Composition and distribution of the larval decapod community in the deep sea of the Western Mediterranean Sea Balearic Sub-basin

Mechanisms facilitating larvae transport from continental to more oceanic areas were investigated in the Balearic sub-basin (BSB), Western Mediterranean Sea. The abundance, distribution, and development stages of decapod larvae were recorded for a transect of 28 stations crossing the central eddy of the BSB. Zooplankton samples were taken to 1,800 m depth by horizontal and oblique 500-mu m mesh size nets hauls towed near the benthic boundary (BBL) and in deep scattering layers (DSL). In total, 67 taxa belonging to Decapoda and one Stomatopoda were identified. Advanced development represented 75% of the individuals recorded. 75% species corresponded of adults deep-sea species, 9% were Sergestids mesopelagic species, and the rest 16% corresponded to shelf and coastal species. Cluster assemblages formed were related to the hydrological conditions, water masses dynamics, and geomorphology structures mainly associated with nepheloid layers. Advanced and juvenile specimens of commercial species such as Parapenaeus longirostris, Geryon longipes, and Aristeus antennatus were found close to seafloor BBL. The influence of trophic ecology should be considered as the priority factor of larvae concentrations in deep.