Chrysogorgiidae Verrill, 1883
The family Chrysogorgiidae is distributed worldwide, as far North as Greenland and as far South as Antarctica. The depth distribution of chrysogorgiids ranges from 10 to 3375 m, but most species (> 75%) seem restricted to deep water, inhabiting soft and hard bottoms. Even though there is no published quantification of their abundance, chrysogorgiids are considered common by deep-sea biologists, and are often found along with isidids and primnoids. During recent expeditions in the Northwestern Atlantic (Mountains-in-the-Sea, 2003-04; Deep Atlantic Stepping Stones, 2005), chrysogorgiids were revealed by remotely operated vehicles (ROVs) to be among the tallest and most majestic octocoral colonies inhabiting the Corner and New England Seamounts.
Calcaxonian octocoral family, typically found in the deep sea. Most chrysogorgiid corals are easily recognizable from their spiraling stem, their delicate polyps, and for many, the beautiful metallic luster of their hard skeleton.
Originally described by Verrill 1883 as such: “Axis composed almost entirely of nonspicular calcified material in concentric lamellae. Surface of axis smooth and glossy or with a metallic lustre. Holdfast is root-like (for colonies living in soft substrata) or disk-like (for colonies attached to solid objects). Colonies branched or unbranched and whip-like. Sclerites in most genera are rods, scales, or plates with low or no tuberculation, and little marginal sculpture. Twelve genera are distributed throughout the world's seas, many at great depth.”.
Twenty four nucleotide sequences available from Genbank: http://www.ncbi.nlm.nih.gov/portal/utils/pageresolver.fcgi?log$=activity&recordid=1247245734262576.
A manuscript by Eric Pante and Scott France on the phylogenetics of the Chrysogorgiidae is in preparation for submission to a peer-reviewed journal (as of 07-09-2009).
We are currently working on a phylogeny of the Chrysogorgiidae (manuscript submission expected in Fall 2009). We presented our preliminary results at the Deepsea Coral Symposium held in Wellington, New Zealand in December 2008 (http://coral2008.niwa.co.nz/files/coral-conf-handbook.pdf). Abstract: Chrysogorgiids are among the most commonly encountered octocorals in the deep-sea. Despite their diversity, ubiquity and relative abundance, chrysogorgiids lack systematic treatment. We present the first phylogenetic reconstruction of the family, based on taxa from 8 of 13 recognized genera, using both nuclear (18S) and mitochondrial (cox1 and msh1) markers (2870 bp). The deep-sea genera Metallogorgia, Iridogorgia, Rhodaniridogorgia, Radicipes and Chrysogorgia form a monophyletic clade. The newly described Rhodaniridogorgia is polyphyletic within the Iridogorgia clade. Genetic variability was low (18S) to nonexistent (cox1, msh1) in Metallogorgia, across a wide geographic scale (NW Atlantic, N and S Pacific), suggesting a relatively recent origin of the genus (insufficient time to accumulate mutations at the target markers), or high dispersal capability relative to confamilial species. As multiple Chrysogorgia and Iridogorgia msh1 haplotypes had similar geographic distributions (NW Atlantic and S Pacific), we propose that the later explanation is not likely. The relationship between Radicipes (monophyletic) and Chrysogorgia is poorly resolved, and preliminary data suggest a rapid diversification of the latter. The phylogenetic position of two specimens (sister to Metallogorgia), collected in New Caledonia, suggests the establishment of a new genus. Preliminary analyses suggest either that the family is polyphyletic, or that Stephanogorgia and Trichogorgia, and Isidoides do not belong to the Chrysogorgiidae, as they cluster with ifalukellid and isidid taxa (respectively). This result has strong implications for the phylogeography of the family, as Stephanogorgia and Trichogorgia are primarily tropical, shallow-water genera.
Deep-sea genera Iridogorgia, Metallogorgia, Chrysogorgia commonly found with invertebrate associates (shrimp, galatheid crabs, ophiuroid echinorderms).
Worldwide, as far North as Greenland and as far South as Antarctica. The depth distribution of chrysogorgiids ranges from 10 to 3375 m, but most species (> 75%) seem restricted to deep water.
A preliminary map of the worldwide distribution of the Chrysogorgiidae is available, and a manuscript on the global biogeography of the Chrysogorgiidae, by Eric Pante, Scott France and Les Watling is in preparation for submission to a peer-reviewed journal (as of 07-09-2009). Distribution on the New England Seamounts and Corner Seamount chains (NW Atlantic): Thoma et al. (in review) MEPS.