Benthic Polychaeta (Annelida) from the continental shelf of the Southern Mexican Pacific

The biological material was collected on board O/V “El Puma” from the Universidad Nacional Autónoma de México, during the oceanographic expedition “Sedimento 4” carried out in February 2008. In the continental shelf of the Southern Mexican Pacific (16° 45’ – 17° 14’N; 99° 49’ – 101° 2’W), 38 stations between 42 m and 109 m depth were sampled using a Smith-McIntyre grab (0.1 m2). Samples were collected on soft bottoms, and 82 species belonging to 52 genera and 27 families of Polychaeta (Annelida) were identified. The stations were geo-referenced by the Global Positioning System (GPS) of the vessel and the environmental data of depth (m), temperature (°C), salinity (psu), dissolved oxygen (ml/L), nitrate (mmol/m3) and phosphate (mmol/m3) concentrations, organic carbon (%), sand and mud percentages were also evaluated at each station.