Contributions to Zoology, 76 (3) 153-178 (2007) A centuries old problem in nephtheid taxonomy approached using DNA data (Coelenterata: Alcyonacea) L.P. van Ofwegen, D.S.J. Groenenberg Nationaal Natuurhistorisch Museum Naturalis, P.O. Box 9517, 2300 RA Leiden, The Netherlands, ofwegen@ naturalis.nl Key words: soft corals, Octocorallia, Nephtheidae, Dendronephthya, Litophyton, Neospongodes, Nephthea, Stereo nephthya, taxonomy, internal transcribed spacer I and II, Indo-Pacifi c Abstract Results ............................................................................................. 175 Discussion ...................................................................................... 177 The current centuries old classifi cation of the family Nephthei- Acknowledgements ...................................................................... 178 dae is still mostly based on colony morphology. In this family References ...................................................................................... 178 the Indo-Pacifc genera Litophyton, Nephthea, Dendronephthya and Stereonephthya, and the Atlantic genus Neospongodes form a complex mix of closely related, poorly described species Introduction which cannot be recognized using only colony morphology. At- tempts with the more modern approach of comparing skeleton After the Alcyoniidae Lamouroux, 1812, the family composition (sclerites) have been only partly successful be- cause of the extreme variation of sclerite forms present in these Nephtheidae Gray, 1862, is the most common soft genera. The genus Chromonephthea Van Ofwegen, 2005, intro- coral family in tropical Indo-Pacifi c waters regarding duced for several species previously assigned to Dendroneph- numbers of genera and species. The often colourful thya, Nephthea and Stereonephthya, was established with scle- colonies of nephtheid species can form large aggre- rite morphology, but the true generic status of the majority of gates by asexual reproduction. Most species have tree- the nominal species of these genera remained unresolved. In an or bush-like colonies and can be found from low tide attempt to clarify the phylogenetic relationships between Lito- phyton, Nephthea, Stereonephthya and Chromonephthea four- to the abyss. teen specimens, unidentifi ed but certainly belonging to these In the tropical Indo-Pacifi c twelve nominal genera genera, have been used in molecular analyses. All analyses sup- are currently assigned to the Nephtheidae: Litophyton ported two clades, which could be related to the shape of the Forskål, 1775; Nephthea Audouin, 1828; Lemnalia sclerites present in the polyp stalks. One clade contained the Gray, 1868; Capnella Gray, 1869; Scleronephthya specimens with characters for Stereonephthya along with the Studer, 1887; Dendronephthya Kükenthal, 1905; Chromonephthea specimen as a sister group. The other clade had a ‘true’ Nephthea and Litophyton together with the speci- Stereo nephthya Kükenthal, 1905; Paralemnalia Kü- mens that could not be placed in any particular genus using the ken thal, 1913; Umbellulifera Thomson and Dean, old classifi cation criteria. The consequences of these results for 1931; Leptophyton Van Ofwegen and Schleyer, 1997; nephtheid classifi cation are discussed. Pacifi phyton Williams, 1997; and Chromonephthea Van Ofwegen, 2005. On the basis of a recent molecu- lar phylogenetic study, McFadden et al. (2006) sug- Contents gest that less genera are involved, because in their analysis Lemnalia and Paralemnalia form a clade Introduction .................................................................................... 153 with the alcyoniid Rhytisma Alderslade, 2000, and Short history of the genera Litophyton, Nephthea, Capnella a clade with the paralcyoniid genera Paral- Stereonephthya, Dendronephthya and Neospongodes .......... 154 cyonium Milne Edwards and Haime, 1850, and Stude- The modern classifi cation ........................................................... 154 riotes Thomson and Simpson, 1909. Short descriptions of the material used .................................... 155 Methods .......................................................................................... 173 In the Atlantic, the Antarctic and the colder waters Sequence variation ................................................................. 173 of the Pacifi c an additional seven genera have been Phylogenetic analyses ............................................................ 174 described in the nephtheids, one of which, viz. the 154 Van Ofwegen and Groenenberg – Taxonomy of soft corals (Nephtheidae) using DNA analysis tropical Atlantic Neospongodes Kükenthal, 1903, re- Polyps without a supporting bundle, sembles the Indo-Pacifi c Stereonephthya regarding polyps in catkins ............................................... Litophyton sclerites and colony form. Polyps with a supporting bundle, To date, Litophyton, Nephthea, Dendronephthya polyps in catkins .................................................. Nephthea and Stereonephthya form a complex mix of closely re- Polyps with a supporting bundle, lated but poorly described species. Hence, around 1990, polyps in bundles or alone, no axis ... Stereonephtya the fi rst author started a morphological revision of the Polyps with a supporting bundle, genera Litophyton, Nephthea, and Stereonephthya, also polyps in bundles or alone, including a number of species assigned to Dendroneph- internal axis of spindles ........................ Neospongodes thya and the monotypic Atlantic genus Neospongodes. Polyps with a supporting bundle, A fi rst outcome of this study was the description of the polyps in bundles ................................. Dendronephthya genus Chromonephthea Van Ofwegen, 2005, for sev- eral species previously assigned to Dendronephthya, Dendronephthya is subdivided into three groups: Nephthea and Stereonephthya. Sparsely arborescent branching colonies with slen- In an attempt to clarify the phylogenetic relation- der ramifi cations, and polyps in small insignifi cant ships between some species that are actually classifi ed bundles ........................................................... Divaricata-group with Litophyton, Nephthea, Stereonephthya, and Chro- Close short branching colonies where the polyp monephthea, a few molecular markers previously bundles are assembled, forming large, distinctly round- tested with octocorals were used. By doing so the sta- ed bunches .................................................... Glomerata-group tus of the morphological characters nowadays em- Polyp bundles closely arranged at the same level on ployed in nephtheids can be compared with the result- the ends of the twigs, forming numerous umbrella-like ing phylogeny. crowns. Several umbrella-like sections may combine to form hemispheres ................................ Umbellata-group Short history of the genera Litophyton, Nephthea, Later on, Utinomi (1954) designated Nephthea savignyi Stereonephthya, Dendronephthya and Neospon- Ehrenberg, 1834, as the type species of Dendroneph- godes thya and Stereonephthya papyracea Kükenthal, 1905, as the type species of Stereonephthya. He character- Forskål (1775) described the fi rst Indo-Pacifi c nepht- ized Stereonephthya as follows: (1) supporting bundles heid, Litophyton arboreum, from an unknown locality of the polyps well developed, each with a strong pro- in the Red Sea. According to modern standards his de- jecting tip, (2) ventral side of the polyp stalk with small scription was inadequate. The material on which he tiny rods, (3) polyp heads usually hanging down from based his description is lost. their stalks, like a campanulate fl ower, (4) dorsal points Andouin (1828), referring to plates published by strong, ventral points poorly supported or lacking. Savigny (1817), erected two additional nephtheid gen- Finally, Verseveldt (1983) re-examined Neospon- era from the Red Sea, viz. Ammothea for A. virescens, godes atlantica and N. bahiensis, the two species Kü- and Nephthea, for N. chabrolii. As far as known, the kenthal (1903) referred to Neospongodes. Verseveldt material on which these two taxa were based has been designated a lectotype for N. atlantica and synonymized also lost. N. bahiensis with N. atlantica. He changed the diagno- After this a period followed in which numerous sis of Neospongodes to “Tree-like, very fl abby nepht- nominal genera and subgenera were introduced or syn- heids, with a slender stalk and stem. Polyps isolated onymized. Many new species were described, and oth- and scattered on thin branches and twigs, with sup- ers were moved from genus to genus. porting bundles”. Kükenthal (1903, 1905) made a revision of the nephtheids in which he abandoned Ammothea and de- scribed three more genera, Neospongodes Kükenthal, The modern classifi cation 1903, Dendronephthya Kükenthal, 1905, and Stereo- nephthya Kükenthal, 1905, all of which without as- Re-examination of most of the type specimens of the signing a type species. He presented the following species described in Litophyton, Nephthea and Stereo- classifi cation, which is still used by most authors (for nephthya showed that the characters used by Kükenthal details of terminology, see Bayer et al. (1983)): (1903, 1905) may be problematic: Contributions to Zoology, 76 (3) – 2007 155 1) The presence of a supporting bundle is not as Short descriptions of the material used straightforward a character as suggested by Kü ken- thal (1905). In the re-examined holotype of Lito- The material used for DNA analyses is briefl y charac- phyton acutifolium