Distribution, behaviour and litter interactions of deep-sea crustacean of the Gulf of Cadiz (NE Atlantic)

Abstract

The deep-sea decapod crustacean assemblage of the Gulf of Cadiz is presently poorly characterized. Eighteen ROV video-transects (50 hours) were carried between 173 to 988 m depth on the continental slope. A total of 4339 individuals of 13 taxa were observed. Bathynectes maravigna (98 individuals and 2.3%), and Polybius henslowii (1691 individuals and 39.0%), were the most represented, followed by Munida sp. (1748 individuals, 40.2%). Individuals classified at family level were: Crangonidae (14 individuals, 0.3%), Majidae (1 individual, <0.1%), Paguridae (39 individuals, 0.9%), and Pandalidae (48 individuals, 1.1%). For a large group of animals, only a subclass or infraorder classification was achieved: Eumalacostraca (674 individuals, 15.5%) and Brachyura (2 individuals, <0.1%). Less observed specieswere: Nephrops norvegicus (8 individuals and 0.18%), Parapenaeus longirostris(8 individuals and 0.2%), Plesionika martia (16 individuals and 0.4%), Acanthephyra sp. (2 individuals and <0.1%). Munida sp. occurred in high-density patches in crinoid (Leptometra celtica) facies on the upper slope. P. henslowiiwas found in a contouritic channel. Species reaction to ROV footprint were aggressive (claws forward projectionand within burrow retraction) for Bathynectes maravigna, Munida sp., N. norvegicus, and P.henslowii(burrowingwas reported for the first time in this latter species, to our best knowledge). Species interaction with litter in B. maravigna, Munida sp., P. martia and Pandalidae was observed: individuals hiding under different kind of plastic andmetal artefacts.