Inventory of trapped organisms under Octopus vulgaris (Cuvier, 1797) mantle, caught off Mauritania by Spanish freezer trawlers

Abstract

During the trawl fishing, diverse organisms that share the habitat with Octopus vulgaris Cuvier, 1797 are swept jointly and into the octopuses’ mantle: cephalopods and other molluscs, juvenile and adult fish, crustaceans, algae, etc. This catch is not taken into account in the assessments, and it could be considered as by-catch and as bio-ecological indicators. Spanish cephalopod-targeted trawl fishery is being developed since 1963 in the Saharan Bank. Nowadays, this fishery is carried out by freezer trawlers in Mauritanian waters. Since the mid-70’s researchers from the Centro Oceanográfico de Canarias (COC) based in Tenerife (belonging to the Instituto Español de Oceanografía (IEO)), have carried out biological studies and assessment of these resources. In 2003 the European Basic Data Collection Program (Regulation (EC) 1543/200) was established to accomplish the European requirements and to carry on this line of researching. From January 2010 to April 2011, an intense sampling program has been carried out over O. vulgaris by the Data Collection team from the COC-IEO, in collaboration with ANACEF (Asociación Nacional de Armadores de Buques Congeladores de Pesca de Cefalópodos). In this framework, weekly samples were kept frozen until their analysis. The organisms extracted from the octopus mantle were labelled and conserved after the biological samplings in the laboratory, and analyzed later. An inventory of species and pictures of them is presented.