PT - JOURNAL ARTICLE AU - Sergio Vargas AU - Martin Dohrmann AU - Christian Göecke AU - Dorte Janussen AU - Gert Wöerheide TI - Nuclear and mitochondrial phylogeny of <em>Rossella</em> (Hexactinellida: Lyssacinosida, Rossellidae): a species and a species flock in the Southern Ocean AID - 10.1101/037440 DP - 2016 Jan 01 TA - bioRxiv PG - 037440 4099 - http://biorxiv.org/content/early/2016/01/22/037440.short 4100 - http://biorxiv.org/content/early/2016/01/22/037440.full AB - Hexactinellida (glass sponges) are abundant and important components of Antarctic benthic communities. However, the relationships and systematics within the common genus Rossella Carter, 1872 (Lyssacinosida: Rossellidae) are unclear and in need of revision. The species content of this genus has changed dramatically over the years depending on the criteria used by the taxonomic authority consulted. Rossella was formerly regarded as a putatively monophyletic group distributed in the Southern Ocean and the North Atlantic. However, molecular phylogenetic analyses have shown that Rossella is restricted to the Southern Ocean, where it shows a circum-Antarctic and subantarctic distribution. Herein, we provide a molecular phylogenetic analysis of the genus Rossella, based on mitochondrial (16S rDNA and COI) and nuclear (28S rDNA) markers. We corroborate the monophyly of Rossella and provide evidence supporting the existence of one species, namely Rossella antarctica Carter, 1872 and a species flock including specimens determined as Rossella racovitzae Topsent, 1901, Rossella nuda Topsent, 1901, Rossella fibulata Schulze &amp; Kirkpatrick, 1910, and Rossella levis (Kirkpatrick, 1907).