Systematics and spicule evolution in dictyonal sponges (Hexactinellida: Sceptrulophora) with description of two new species
Version of Record online: 25 NOV 2011
© 2011 The Linnean Society of London
Zoological Journal of the Linnean Society
Volume 163, Issue 4, pages 1003–1025, December 2011
How to Cite
DOHRMANN, M., GÖCKE, C., JANUSSEN, D., REITNER, J., LÜTER, C. and WÖRHEIDE, G. (2011), Systematics and spicule evolution in dictyonal sponges (Hexactinellida: Sceptrulophora) with description of two new species. Zoological Journal of the Linnean Society, 163: 1003–1025. doi: 10.1111/j.1096-3642.2011.00753.x
- Issue online: 25 NOV 2011
- Version of Record online: 25 NOV 2011
- Received 6 October 2010; revised 25 March 2011; accepted for publication 28 March 2011
- Deep Down Under Expedition;
- molecular systematics;
In this paper we report on recently collected specimens of glass sponges belonging to Farreidae Gray, 1872, and Tretodictyidae Schulze, 1886 (Porifera: Hexactinellida: Hexactinosida). All specimens represent new geographical records for their genera: Coral Sea for Aspidoscopulia Reiswig, 2002 (Farreidae) and Psilocalyx Ijima, 1927 (Tretodictyidae); north-west Atlantic for Sarostegia Topsent, 1904 (Farreidae). Two new species, Aspidoscopulia australia Dohrmann, Göcke & Janussen sp. nov. and Aspidoscopulia ospreya Dohrmann, Göcke & Janussen sp. nov., are described. To investigate further the evolution of hexactinosidan sponges, we sequenced two nuclear (18S and 28S rDNA) and two mitochondrial [16S ribosomal rDNA, cytochrome oxidase subunit I (COI)] genes from these specimens, as well as from a recently described new species of Lonchiphora Ijima, 1927 (Farreidae). Besides corroborating the monophyly of Tretodictyidae, our molecular phylogenetic analyses support a clade of clavule-bearing sponges with a farreoid dictyonal framework (i.e. Farreidae sensu stricto). In contrast, Sarostegia, which lacks these features, appears unrelated to this clade – instead our data are consistent with an earlier placement of this genus in Euretidae Zittel, 1877. We introduce formally the taxon Sceptrulophora Mehl 1992, and emend the classification of Hexactinosida to reflect this move and our new findings regarding the position of Sarostegia. Finally, we discuss implications of the molecular phylogeny for the evolution of sceptrules, the defining autapomorphy of Sceptrulophora.
© 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163, 1003–1025.