The aberrant and monotypic soft coral genus Malacacanthus Thomson, 1910 (Octocorallia: Alcyoniidae) endemic to southern Africa

The monotypic soft coral genus Malacacanthus has recently been rediscovered by means of scuba and is shown to be locally common and endemic in the shallow sublittoral of South Africa. Malacacanthus capensis (Hickson, 1900) is shown to be the proper taxonomic designation for the species. This species has previously been a problematic one due to the possession of several unusual morphological characteristics, including the total lack of sclerites and possession of a tough horny cuticle covering the stalk. The taxon is here shown to belong in the family Alcyoniidae by the possession of a full complement of mesenterial filaments, and not to the family Xeniidae as assigned by several previous authors. The species is here redescribed and the systematic status is revised. New observations on ecology and natural history from living colonies are also included.