<jats:title>Abstract</jats:title><jats:p>Glass sponges (Porifera, Hexactinellida) are conspicuous habitat-forming members of many Antarctic shelf communities. Despite their ecological importance, in-situ species identification remains problematic as it is traditionally based on microscopic analysis of spicules. External morphological features, in contrast, have largely been disregarded, so that different species have been mislabeled or lumped together when their identification was based on image material. In this paper, we provide a straight-forward guideline for in-situ identification of the most common rossellid sponges of the Antarctic shelf based on macroscopic characteristics. To determine diagnostic macroscopic characteristics of <jats:italic>Anoxycalyx (Scolymastra) joubini</jats:italic> and eight <jats:italic>Rossella</jats:italic> species, we combined examination of trawl-collected specimens, previous species descriptions and in-situ image material from the eastern Weddell Sea. Our study revealed that the smooth-walled species <jats:italic>A. joubini</jats:italic>, <jats:italic>R. nuda</jats:italic> and <jats:italic>R. vanhoeffeni</jats:italic>, previously often mixed up, can be distinguished by the form of their basal spicule tuft, their surface structure and their overall body form. The previously synonymized species <jats:italic>R. racovitzae</jats:italic> and <jats:italic>R. podagrosa</jats:italic> can be distinguished by their markedly different habitus. Based on our results, the so-called ‘<jats:italic>R. racovitzae</jats:italic> budding type’ in fact refers to <jats:italic>R. podagrosa</jats:italic> which occurs regularly in the eastern Weddell Sea. The species <jats:italic>R. villosa</jats:italic>, <jats:italic>R. levis</jats:italic>, <jats:italic>R. fibulata</jats:italic> and <jats:italic>R. antarctica</jats:italic> can be distinguished by the appearance of their conules, protruding spicules and overall body form. We conclude that macroscopic characteristics are helpful means for identification of Antarctic rossellid sponge species. This approach enables species-specific quantitative studies of Antarctic glass sponge grounds based on increasingly used non-invasive imaging technology.</jats:p>