Amphipods from the Mar del Plata Submarine Canyon, Southwest Atlantic Ocean.

CHIESA, I.; MARTÍNEZ, A.; DOTI, B.L.

Aveiro

Congreso; Deep Sea Biology Symposium; 2015

Universidad de Aveiro

Peracarids are known to be extremely diverse in the benthic deep sea. Particularly for the amphipods, in the whole Southern Ocean 80 species have been cited below 1000 m depth. The Mar del Plata Submarine Canyon is situated approximately 300 km east to Buenos Aires province, Argentina. In August 2012, a total of 4 benthic samples were taken on board the RV ?Puerto Deseado? during the first Argentine expedition conducted in this area. The preliminary results presented herein are based on the study of a single sample taken in 37º57.9? S, 54º31.9? W, at 1144 m depth, using an epibenthic sledge equipped with a net of 1 mm mesh size. At least 38 species (some of them new to science) of benthic amphipods, belonging to 21 families were identified: Acanthonotozomellidae, Ampeliscidae, Ampithoidae, Caprellidae, Colomastigidae, Cyproideidae, Dexaminidae, Epimeriidae, Eusiridae, Ischyroceridae, Leucothoidae, Liljeborgiidae, Lysianassidae s.l., Melitidae, Oedicerotidae, Photidae, Phoxocephalidae, Podoceridae, Stegocephalidae, Stenothoidae and Urothoidae. The most abundant and diverse families were Ampeliscidae, Ischyroceridae, Lysianassidae and Phoxocephalidae. Within the peracarid crustaceans, Asellota isopods are usually the dominant group in the deep sea. Nevertheless, in the same sample considered for this study, a smaller number of isopods species were identified, viz: 33 species (27 of these were asellotes). In the Argentine continental margin only 15 species of benthic amphipods had been recorded beyond 300 m depth, these preliminary results aim to improve the knowledge about the amphipods biodiversity in the deep southwest Atlantic Ocean.