New genus and species of black coral from the SW Pacific and Antarctica (Cnidaria: Anthozoa: Antipatharia: Schizopathidae).

Abstract

A new genus, Diplopathes, in the family Schizopathidae, and three new species are described from the Southwest Pacific and Antarctic region based on morphological data. The new genus superficially resembles Telopathes in being branched and having simple, bilateral pinnules, but differs in having strictly alternately arranged pinnules, and in having small polyps 4 mm or less in transverse diameter. Mitochondrial DNA placed Diplopathes and Telopathes in separate clades within the Schizopathidae, thus supporting the significance of seemingly subtle anatomical differences. The new species are: D. antarctica, with sparse branching, pinnules of up to 7 cm long, and polypar spines up to 0.045 mm tall; D. multipinnata, with dense branching, pinnules up to 3 cm long, and polypar spines up to 0.1 mm tall; and D. tuatoruensis, with very sparse branching, pinnules up to 10 cm long, and polypar spines up to 0.1 mm. Interestingly, the three new species do not form a monophyletic clade based on mitochondrial DNA. We propose and discuss two hypotheses to explain the results of the phylogenetic reconstruction, including that molecular and physical change are uncoupled or that we have uncovered another example of morphological convergence in unrelated species.