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The family Artedidraconidae comprises small, endemic Antarctic fishes, known as plunderfish, mostly distributed in the High Antarctic region. To study the diet of these specialised benthic feeders, stomach contents of the 11 most abundant species in the eastern Weddell Sea were examined. Prey composition was identified to the lowest taxonomic level for peracand crustaceans and polychaetes. Half of the food volume compr~sed 36 crustacean taxa (26 of which were amphipods). The other half was made up of 7 polychaete taxa and 8 other zoological groups. The diet of plunderfishes < 20 cm long was found to include about 70 % peracarid crustaceans, 50 % of which were amphipods. mainly garnrnarids; the rest of their diet was mostly sessile and motile polychaetes. Individuals larger than 15 cm began to prey on other fishes, although garnmands were stdl a part of their diet. The size of prey ranged from 5 to 32 mm. The mean size of prey increased with predator size. Selective predation effects were observed. small prey (copepods, cumaceans, ostracods, the gamrnarid family Eusiridae s.1. and the polychaete family Phyllodocidae) were found more frequently in small predators, whereas large prey (Epimeriidae, Lysianassidae s.1.. Cirolanidae, Arcturidae, Crangonidae. Euphausiidae. Pycnogonida) appeared in the stomachs of predators larger than a certain size. Plunderfish prey are generally abundant in the area, but the high diversity of the diet found in the genus Artedidraco, compared with the genera Dolloidraco and Pogonophryne, was surprising. The present analysis is based on data concerning the distribution and abundance of predators, as well as biological knowledge regarding the most characteristic types of prey. The specialised d e t s of plunderfishes from different habitats and of different sizes are also compared, in order to more closely examine the feedmg strategy of the family Artedidraconidae, and roughly quantify its impact on the benthic trophic web.

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SUMMARY: To investigate the marine benthic ecosystems of the Magellan region and to compare them with the better known Antarctic systems, three campaigns were recently carried out in this area: the Joint Magellan "Victor Hensen" Campaign 1994, the "Polarstern" ANT XIII/4 cruise 1996, and the "Vidal Gormaz" CIMAR FIORDO II cruise 1996. Numerous and diverse zoobenthos samples were collected mostly with an Agassiz trawl and with a small dredge, an epibenthic sledge, with baited traps or by diving. All gears together gathered more than 132,000 specimens of gammaridean and caprellidean amphipods. 137 species of gammaridean amphipods have been identified from the material to date. About 20% of these species appear to be new for science. This taxonomic work takes place in the framework of a general revision of the Southern Ocean amphipod fauna undertaken by the"Antarctic Amphipodologists Network". A complete list of the benthic species of gammaridean and caprellidean amphipods is presented, including the zoogeographical distribution and the new records. The new abundant material collected, still under study, will allow a comparison of faunal diversity, zoogeographical and ecological traits of the Magellan benthic amphipod taxocoenoses with those of the West and East Antarctic benthos.Key words: Biodiversity, Amphipoda, benthos, Magellan region, zoogeography. RESUMEN: DIVERSIDAD FAUNÍSTICA DE LOS ANFÍPODOS (CRUSTACEA) DE LA REGIÓN DE MAGALLANES EN COMPARACIÓN CONLA DE LA ANTÁRTIDA (RESULTADOS PRELIMINARES). -En el área de Magallanes se han Ilevado a cabo recientemente tres campañas de investigación: la campaña con B/I "Victor Hensen" en 1994, y las campañas "Polarstern" ANT XIII/4 y CIMAR FIORDO II con el B/O "Vidal Gormáz" en 1996. En las tres campañas se recoltaron numerosas y muy variadas muestras de organismos bentónicos. Las muestras se recogieron principalmente con la red Agassiz y mediante buceo. Los anfípodos se recolectaron también mediante una pequeña rastra y con trampas con cebo. En el conjunto de todas las muestras se recolectaron más de 132.000 especímenes de anfípodos gammáridos y caprélidos. La mayor parte de estos ejemplares se ha identificado, habiéndose obtenido unas 137 especies de las que un 20% son especies nuevas para la ciencia. El trabajo taxonó-mico efectuado se ha desarrollado en el marco del programa de revisión de la fauna de anfípodos del Oceáno Austral que lleva a cabo la "Antarctic Amphipodologists Network". El abundante material nuevo recolectado, en parte aún por estudiar, permitirá reevaluar las afinidades zoogeográficas, el origen y la dispersión de la fauna de anfípodos bentónicos de la región de Magallanes en relación con la fauna antártica del grupo.

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