Spatial distribution and abundance of the Stomatopoda and Decapoda crustaceans sampled by bottom trawl in the gulf of Gabes (Tunisia, Central Mediterranean)

Stomatopoda and Decapoda crustaceans play an important role in the marine ecosystems through varied ecological strategies and bio-disturbance of species' community with an important effect on the benthic communities' structure, in addition to abiotic factors (such as temperature, salinity and type of bottom). Furthermore, faunal inventories are necessary, especially when focused on ecological and economical important groups, such as the Malacostraca class, and concentrated on areas under intense fishery activity such as the gulf of Gabes (Central Mediterranean). Inshore and offshore collections were performed at 30 sites of the Gulf's continental shell (20-260 m depth) in spring 2009, by employing two experimental bottom trawl gears. Overall, 40 species were detected in the samples distributed among Stomatopoda (only one species) and Decapoda (7 Dendrobranchiata, 3 Caridea, 1 Astacidea, 7 Anomura, and 21 Brachyura). In terms of abundance, Stomatopoda contributed for about 14\%. The coastal area of the gulf (especially, areas in the North-east of Gabes and North-west of Djerba between 20 and 40 m depth) hosted a high variety of species; the most abundant were Squilla mantis, Paguristes eremite, Inachus dorsettensis and the exotic intruder Trachysalambria palaestinensis.