Advances on the phylogenetic placement of the enigmatic octocoral Dendrobrachia Brook 1889.

The monogeneric family Dendrobrachiidae has been a taxonomic curiosity since its original description in 1889. Using one nuclear (18S) and two mitochondrial (mtMutS and cox1) genes, the phylogenetic placement of Dendrobrachiidae within the Octocorallia was investigated based on recently-collected specimens and museum collections. In particular, the relationship between Dendrobrachia and its suspected close allies from the Chrysogorgiidae and Ifalukellidae was examined. Phylogenetic inferences based on nuclear 18S sequences were inconclusive. On the basis of mitochondrial cox1 and mtMutS, the hypothesis that Dendrobrachia is closely related to the Chrysogorgiidae or the Ifalukellidae could be rejected with confidence. Dendrobrachia appeared distantly related to all octocoral groups considered here. However, the phylogenetic placement of Dendrobrachia could not be further clearly resolved.