Sponges (Porifera: Demospongiae) recorded at the South Shetland Islands and near the Antarctic Peninsula during the Argentinian Summer Antarctic Expedition in 2012

While in recent years there have been many scientific expeditions to Antarctica, there is still plenty to discover about it’s marine biodiversity, especially in certain regions, and particularly in regards to benthic organisms such as sponges (Phylum Porifera). The Argentinian 2012 Summer Antarctic Expedition took place between February and March of 2012. One of its main goals was the study of the benthic communities, considering the biodiversity and the distribution of the species around the Antarctic Peninsula and neighbouring islands. Samples were collected by bottom trawling at eight locations. Sponges were sorted from total catch, photographed, labeled and frozen onboard, while identification was carried out using classical methodology at the Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP, Argentina). In this preliminary study we provide the identification and location of the samples belonging to the Demospongiae Class. A total of 34 samples were collected and 23 species were identified. The most represented Order was Poecilosclerida with 18 species (Isodictya erinacea, I. lankesteri, I. cf. verrucosa, Mycale (Oxymycale) acerata, M. cf. tridens, Phorbas glaberrimus, P. acantochela, Lissodendoryx anacantha, L. flabellata, L. ramilobosa, Artemisina apollinis, Myxodoryx hanitschi, Clathria (Axosuberites) nidificata, Tedania charcoti, Iophon unicorne, I. cf. aceratum, Myxilla mollis, Kirkpatrickia aff. coulmani), followed by Haplosclerida with 5 species (Haliclonissa verrucosa, Haliclona sp. Calyx cf.arcuarius, Microxina charcoti, Hemigellius cf. pilosus). The most frequently recorded species was Mycale (Oxymycale) acerata followed by species of the genus Isodictya and Lissodendoryx. Some of the recorded species such as Phorbas glaberrimus, Myxodoryx hanitschi, Phorbas cf. acanthochela and Raspailia (Hymeraphiopsis) hentscheli have only scarce records in this region. The results of this study greatly contribute to the knowledge on the distribution and biodiversity of Antarctic sponges, a very important component of the benthic communities.