Abstract
The genus Heterogorgia Verrill, 1868 is poorly known. Lack of good illustrations and clear definitions have historically led authors to assign or transfer species erroneously to it. The genus was established by Verrill for three eastern Pacific species, another was described by Breedy and Guzman in 2005, and the geographic distribution was extended with the discovery of a western Atlantic species described by Castro in 1990. Heterogorgia is characterised by colonies composed of a number of stout stems that branch laterally and irregularly and arise from a conspicuous spreading holdfast. Coenen-chymal sclerites are mostly colourless spindles; anthocodiae have strong spindles arranged in collaret and points; and the calyces are prominently armed withwhorls of strongly projecting thorns. To define Heterogorgia we examined original type material of all eastern Pacific and western Atlantic species described until now and reference specimens from recent expeditions along the eastern Pacific. Morphological characters are analysed and illustrated using scanning electron micrographs. Lectotypes are designated for H. tortuosa and H. verrucosa to establish their taxonomic status. We conclude that Heterogorgia is comprised of five valid species at present: Heterogorgia hickmani and H. verrucosa for the Galapagos Islands and Ecuador mainland; H papillosa for Mexico; H. tortuosa and H verrucosa for Costa Rica and Panama; and H. uatumani for Brazil and Bahamas. The genera Astromuricea, Bebryce, Echinogorgia and Psammogorgia are proposed for the western Pacific species that were historically misplaced in Heterogorgia. We recommend that regional biodiversity estimates and biogeography analyses consider the erroneous status of the species that are still listed as Heterogorgia within the data sets.
NSTL