RT Journal Article SR Electronic T1 Nuclear and mitochondrial phylogeny of Rossella (Hexactinellida: Lyssacinosida, Rossellidae): a species and a species flock in the Southern Ocean JF bioRxiv FD Cold Spring Harbor Laboratory SP 037440 DO 10.1101/037440 A1 Sergio Vargas A1 Martin Dohrmann A1 Christian Göecke A1 Dorte Janussen A1 Gert Wöerheide YR 2016 UL http://biorxiv.org/content/early/2016/01/22/037440.abstract 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 & Kirkpatrick, 1910, and Rossella levis (Kirkpatrick, 1907).