The early life stages of the blue and red shrimp Aristeus antennatus (Decapoda: Dendrobranchiata: Penaeoidea: Aristeidae) were described by Heldt in 1955 based on plankton samples, larval rearing and assumptions of species habitat. Even with adequate keys, identification of its first larval stages remained a difficult task due to the lack of specific morphological characters which would differentiate them from other Penaeoidea species. Larvae of Aristeus antennatus were collected in the continental slope off the Spanish Mediterranean coast in August 2016 with a neuston net and preserved in ethanol 96%. DNA from the larvae was extracted and the molecular markers Cytochrome Oxidase I and 16S rDNA were sequenced and compared to that of adults with the objective of confirming the previous morphological description. Then, we present additional information to the morphological description of Aristeus antennatus larval stages through scanning electron microscopy and molecular analysis. This represents the first documented occurrence of Aristeus antennatus larvae off the Catalan coast and sets the grounds for further work on larval ecology and population connectivity of the species, which is an important contribution to a more sustainable fishery.

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Abstract. Marine biophysical models can be used to explore the displacement of individuals in and between submarine canyons. Mostly, the studies focus on the shallow hydrodynamics in or around a single canyon. In the northwestern Mediterranean Sea, the knowledge on the deep-sea circulation and its spatial variability in three contiguous submarine canyons is limited. We used a Lagrangian framework with three-dimensional velocity fields from two hydrodynamics models to study the deep bottom connectivity between submarine canyons and to compare their influences on the particle transport. The particles represented eggs and larvae spawned by the deep-sea commercial shrimp Aristeus antennatus along the continental slope in summer. The passive particles mainly followed a southwest drift along the slope and drifted less than 200 km within 31 days. Two of the sub-marine canyons were connected by more than 27 % particles if they were released at sea bottom depths above 600 m. The vertical displacement of particles was depending on the submarine canyons, the depth and the can-yon wall where particles were released and it encouraged the analyses of the particle transport by canyons in-stead of generalizing the dynamics. In the two hydrodynamic models tested in this study, passive drift simulation differed depending on topography. Despite being run on a coarser grid, the hydrodynamic model using finer bathymetric resolution data and adjusted to the topography seemed to better model the passive drift of particles. Those results promote that the physical model parameterization has to be considered for improving the transport studies of deep-sea species.