ZOOTAXA
ISSN 1175-5326  (print edition)
ISSN 1175-5334 (online edition)Copyright © 2017 Magnolia Press
Zootaxa 4319 (1): 001–026  
http://www.mapress.com/j/zt/
Article
https://doi.org/10.11646/zootaxa.4319.1.1
http://zoobank.org/urn:lsid:zoobank.org:pub:FC97523C-3FE9-4BD1-9A3B-174E0969E78A
A revision of the genus Radicipes Stearns, 1883 
(Anthozoa: Octocorallia: Chrysogorgiidae) 
RALF T. S. CORDEIRO1, STEPHEN D. CAIRNS2 & CARLOS D. PEREZ3
1Programa de Pós-Graduação em Biologia Animal, Universidade Federal de Pernambuco, Recife, PE, Brazil. 
E-mail: ralfts@gmail.com
2Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, PO Box 37012, MRC 163, Wash-
ington, DC 20013-7012, USA. E-mail: cairnss@si.edu
3Centro Acadêmico de Vitória, Universidade Federal de Pernambuco, Vitória de Santo Antão, PE, Brazil. E-mail: cdperez@ufpe.br
Abstract
Radicipes is an octocoral genus composed of whip-like chrysogorgiids. Representatives of this group, also called ‘pig-
tails’, occur in almost all continental margins around the globe. Since its description in the 19th century, no comprehensive 
revision of this genus has been made. Thus, we present herein a revision of Radicipes, with descriptions of previously 
known species and one new species, Radicipes stonei. Type specimens from several museums were examined and seven 
species are considered valid. A distribution map of the genus and illustrations for all species are provided and a brief dis-
cussion is given on the possibility of additional undescribed species.
Key words: Alcyonacea, new species, deep-sea, pigtails
Introduction
Since it was proposed in the 19th century, the family Chrysogorgiidae Verrill, 1883 is purported to encompass at 
least 15 genera (Bayer, 1981; Bayer & Stefani, 1988; Cairns & Cordeiro, 2017). These so-called 'golden corals’ 
were known to inhabit diverse marine environments, from shallow reefs to abyssal depths. Nonetheless, with the 
increasing use of molecular techniques this situation is changing; current interpretation of data indicates that the 
family has a polyphyletic origin, based on sequencing of three genes and the extinction pattern revealed when 
sclerites are exposed to polarized light (Pante et al., 2012). The family is currently considered to be composed of a 
strongly supported monophyletic clade of only six genera, called the "Monophyletic Chrysogorgiidae Clade" by 
Pante et al. (2012), consisting of: Chrysogorgia Duchassaing & Michelotti, 1864, Iridogorgia Verrill, 1883, 
Rhodaniridogorgia Watling, 2007, Pseudochrysogorgia Pante & France, 2010, Metallogorgia Versluys, 1902 and 
Radicipes Stearns, 1883. This clade is equivalent to Chrysogorgiidae sensu stricto, as it includes the type genus
Chrysogorgia. Pante et al. (2012) imply that the other eight remaining genera may fall into as many as four other 
families. Nonetheless, the same authors present Radicipes as a monophyletic subclade with the Chrysogorgiidae 
consisting of typical cold- and deep-water octocoral genera (Watling et al., 2011).
Representatives of Radicipes, sometimes called “pigtails”, form coral meadows in soft bottoms of continental 
slopes and seamounts of all oceans (Stone, 2005; Buhl-Mortensen et al., 2010; Watling et al., 2011), in densities of 
2.34–2.39 colonies/m2 and most of the records being in temperate zones between 241 to more than 3500 m depth 
(Althaus et al, 2009; Gonzalez-Mirelis & Buhl-Mortensen, 2015). Along with Chrysogorgia, they have a very 
broad bathymetric distribution (Watling et al., 2011) and seven of the deepest octocoral records belong to members 
of these genera (Cairns, 2015). Regions around the globe without records of the genus correspond to poorly-
explored sites; enhancement of collections in these areas will probably add new species to the group.
Most of the revisions of Radicipes were performed within a few decades after the species were described in the 
late 19th century (Kükenthal, 1919; Verrill, 1922; Kükenthal, 1924). Two final accounts of the group were made by Accepted by J. Thoma: 31 Jul. 2017; published: 11 Sept. 2017  1
Madsen (1944) and Cordeiro et al. (2015). These two studies list eight species in the genus. Until now, none of the 
revisions made were based on the examination of all the types (excluding those that were likely lost). Thus, in this 
study, we present a complete revision of Radicipes, including the description of a new species.
Materials and methods
Although ubiquitous in all oceans, the slender nature of the usually firmly attached colonies of Radicipes makes 
collection of specimens a rare event. Thus, most species of the genus were described based on few samples. For 
example, there are taxa represented by one or two specimens that have been sampled only once in more than a 
century. Despite the paucity of specimens, we still consider it appropriate to describe species based on a few 
specimens herein, rather than wait for new collections, not likely to occur any time soon. All type specimens were 
re-examined and a list of all records used herein is provided (Supplementary file).
The terminology used herein follows Bayer et al. (1983). The distribution map was prepared using QGIS 
(2015).
Abbreviations. Institutions: BMNH: The Natural History Museum, London; MCZ: Museum of Comparative 
Zoology, Harvard University, Cambridge, Massachusetts; NIWA: National Institute of Water and Atmospheric 
Research, Wellington; OBIS: Ocean Biogeographic Information System; USNM: United States National Museum 
(National Museum of Natural History—NMNH), Washington, DC; YPM: Yale Peabody Museum of Natural 
History, New Haven, Connecticut; MNRJ: Museu Nacional, Rio de Janeiro; ZMB: Zoologisches Museum, Berlin. 
Research vessel/ Cruises: Alb: USFWS Albatross; Chall: Challenger Expedition; Del: Delaware II R/V, NOAA 
Climate; Ger: Gerda R/V; J or JD corresponds to stations of the Jason II ROV, aboard of the R/V Roger Revelle; 
Or: R/V Oregon ; Pill: R/V Pillsbury; R/V Thal: Thalassa , REVIZEE Bahia II cruise.
Taxonomy
Subclass Octocorallia Haeckel, 1866
Order Alcyonacea Lamouroux, 1812
Suborder Calcaxonia Grasshoff, 1999
Family Chrysogorgiidae Verrill, 1883
Genus Radicipes Stearns, 1883
Radicipes Stearns, 1883: 97.—Kinoshita, 1913: 5.—Jungersen, 1915: 1183.—Kükenthal, 1919: 540 (in part: not R. 
squamiferus).—Verrill, 1922: 41.—Kükenthal, 1924: 410.—Deichmann, 1936: 236. —Madsen, 1944: 44.—Bayer, 1956: 
F216, text-fig. 3.—Bayer & Muzik, 1976: 68 (key to genus).—Bayer & Stefani, 1988: 258 (key to genus).—Williams, 
1992: 252. —Pante & France, 2010: 600 (key to genus, molecular phylogeny).—Cordeiro et al., 2015: 94.
Lepidogorgia Verrill, 1884: 220 (type species: L. gracilis Verrill, 1884, by monotypy); 1885: 512.—Versluys. 1902: 5.—
Thomson & Henderson, 1906: 26–27 (tabular key to species).—Nutting, 1908: 587–588 (in part: not L. gibbosa).—
Thomson, 1927: 20.
Strophogorgia Wright, 1885: 691 (nom. nud.). 
Strophogorgia Studer, 1887: 41 (nom. nud.).
Strophogorgia Wright & Studer, 1889: 2 (type species: Strophogorgia challengeri Wright & Studer, 1889, subsequent 
designation).
Type species. Radicipes pleurocristatus Stearns, 1883, by monotypy.
Diagnosis. Unbranched (flagelliform) chrysogorgiids, brittle, sometimes elongate (up to 1 m long), and often 
loosely coiled, arising from a root-like calcareous holdfast. Polyps arranged uniserially along one side of axis, 
delimiting a polypar and an abpolypar face, the former usually facing inner part of colony spiral. Coenenchyme 
usually quite thin. Axis slightly quadrangular to round in cross-section. Sclerites composed of irregularly shaped 
scales and rods. CORDEIRO ET AL.2  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press
Discussion. Three genera were proposed almost simultaneously: Radicipes Stearns (1883), Lepidogorgia 
Verrill (1884) and Strophogorgia Wright (1885). Kinoshita (1913) was the first author to establish the synonymy 
among these three genera. The first publication in which the name Strophogorgia appears (Wright, 1885) has no 
descriptions or specimen designations. Along with the creation of the subfamily Strophogorginae, Studer (1887) 
provided the first description of Strophogorgia (by monotypy), but did not list any species. Descriptions associated 
with species were given only subsequently, by Wright & Studer (1889). Thus, Strophogorgia Wright, 1885 and 
Strophogorgia Studer, 1887 are considered herein as nomen nudum, and the next available publication date is 
Strophogorgia Wright & Studer, 1889. Its type-species is Strophogorgia challengeri Wright & Studer, 1889, in 
accordance with recommendation 69A of the International Code of Zoological Nomenclature (ICZN, 1999).
Among the 15 genera previously assigned to Chrysogorgiidae, only five have unbranched colonies: Radicipes, 
Helicogorgia Verrill, 1883, Chalcogorgia Bayer, 1949, Distichogorgia Bayer, 1979 and Flagelligorgia Cairns & 
Cordeiro, 2017. Radicipes can be distinguished as being the only unbranched chrysogorgiid genus to have 
uniserially arranged polyps, the other three unbranched genera having bi- or multiserially arranged polyps. The 
monophyly of Radicipes implied by this morphological distinction is reinforced by molecular sequencing of both 
mitochondrial and nuclear genes (Pante et al., 2012), its sister group suggested to be Chrysogorgia (Pante & 
France, 2010; Pante et al., 2012).
The low number of morphological characters, as well as the low number of samples for some species makes 
the systematics of this genus difficult. Intracolony variation is also a challenge. For instance, in a single colony, the 
basal coenenchymal sclerites may be quite different from those in the median region. Similarly, some species have 
the coenenchyme between polyps filled with the same sclerites as those seen in the body wall (Table 1). Sclerite 
densities in polyps may also vary according to age and position in a colony. Also, size, arrangement and shape of 
the sclerites from the polyp base can be drastically modified within a specimen, when it is fully developed or 
sexually mature (Figs. 1E, 2H-I’). In the same way, mature polyps usually show an enlargement at the base and at 
the oral portion.
The unbranched and usually coiled nature of the Radicipes colony (Figs. 1A,D) make it similar to other deep-
water unbranched Cnidaria, such as some species of octocorals of the genera listed as follows: Ainigmaptilon,
Bathygorgia, Callozostron, Calyptrophora, Ellisella, Helicoprimnoa, Lepidisis, Narella, Narelloides, Onogorgia, 
Ophidiogorgia, Perissogorgia, Viminella and the antipatharian genera Cirripathes and Stichopathes. Thus in situ
observations based on photographs must be made with care.
Distribution. The genus Radicipes shows a broad distribution, latitudinal and bathymetric (Fig. 3 and Table 1: 
241–3580 m), with most of the records (about 80%) for the genus belonging to two species, Radicipes gracilis
(Verrill, 1884) and R. pleurocristatus. The least reported species is Radicipes spiralis (Nutting, 1908), recorded 
only at the occasion of its description. The records incorporated herein were given by Watling et al. (2011) and 
Pante et al. (2012). Another source of biogeographic information is the “Ocean Biogeographic Information 
System” (OBIS), which also provides environmental conditions to better understand the requirements for the 
occurrence of Radicipes populations (see: http://iobis.org/explore/#/taxon/502435). 
As most of the records of the genus given by Watling et al. (2011) were based on expedition and collections 
data (see Watling et al., 2011: p.70, fig. 2.5), it is likely that their Antarctic record was based on one previously 
misidentified specimen (USNM 1019007—a clavulariid attached to a Primnoella sp. stem). Indo-Pacific 
specimens recorded by Pante et al. (2012) and Alderslade et al. (2014) and South African specimens noted by 
Williams (1992) were identified only to genus level. Buhl-Mortensen et al. (2010: 43, fig. 42) show Radicipes sp. 
at around 700 m in Norwegian waters. Other records include the mid-Atlantic Ridge (Mortensen et al., 2008), off 
Norway (Gonzalez-Mirelis & Buhl-Mortensen, 2015), the Gulf of Vizcaya (France) (Altuna, 2010), and the Gulf of 
Cádiz (Spain) (Rueda et al., 2012) (Fig. 3). 
Key to species of Radicipes Stearns, 1883
1. Sclerites virtually absent or rare in polyp body wall. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .R. spiralis
1a. Sclerites always present in polyp body wall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Body wall sclerites predominantly long scales with irregular margins. . . . . . . . . . . . . . . . . . . . . . . . . . . R. aureus (Fig. 14A,B)
2a. Body wall sclerites predominantly rods, flattened rods or scale-like rods with regular margins . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Body wall sclerites predominantly flattened to slightly rounded rods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  3REVISION OF RADICIPES 
3a. Body wall sclerites predominantly rounded rods, sometimes with one flattened tip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Fully developed polyps with body wall filled by sclerites longitudinally arranged in eight regular rows (adaxials less devel-
oped) and usually able to keep its shape when dry; rounded to slightly flattened rods as body wall sclerites; completely flat-
tened rods rare in body wall  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .R. gracilis (Fig. 2E–F)
4a. Fully developed polyps rarely with eight regular longitudinal sclerite rows and usually unable to keep its shape when dry; flat-
tened rods as body wall sclerites; rounded rods rare in body wall . . . . . . . . . . . . . . . . . . . . . . R. challengeri (Fig. 2A,B, 11, 12)
5. Coenenchymal sclerites 8-shaped scales; polyps usually unable to keep its shape when dry  . . . . . . . . . . R. kopelatos (Fig. 2D)
5a. Coenenchymal sclerites longitudinally curved rods; polyps usually able to keep its shape when dry . . . . . . . . . . . . . . . . . . . . . 6
6. Body wall sclerites long rounded rods, reaching 2.0 mm or more in length; coenenchymal sclerites strongly sculptured (woody 
in appearance) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R. pleurocristatus (Fig. 2H–I’, 4, 5)
6a. Body wall sclerites long rounded rods, up to 0.8 mm long; coenenchymal sclerites weakly sculptured . . . R. stonei (Fig. 2C, 6)
FIGURE 1. Schematic representation of a colony of Radicipes. A: gross morphology of a gorgonian Radicipes spiralis in their 
natural environment (Nutting, 1908) (NOAA-Okeanos Explorer, Expedition 1504, leg 2); B: common sclerite arrangement on 
polyps; C: relative proportion between different sclerite classes in Radicipes pleurocristatus Stearns, 1883 (rods from body 
wall, tentacular and pinnular rods and coenenchymal scales); D: close-up view of polyp arrangement in the latter colony; E: 
coenenchymal deformed scales from the base of the colony; F: calcified holdfast; G: polypar face in polypar portion; H: 
abpolypar face in polypar portion; I: sterile portion (basal) of the colony (usually first one third of the colony without polyps). 
ab: abaxial side; ad: adaxial side; sb: saddle bag portion (infrabasal).CORDEIRO ET AL.4  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press
FIGURE 2. Polyps of Radicipes spp. A, B: polyps of Radicipes challengeri (Wright & Studer, 1889) (BMNH1889.5.27.3, 
holotype, and USNM 57314, respectively); C: polyp of Radicipes stonei sp. nov. (USNM 1418007, holotype); D: polyp of 
Radicipes kopelatos Cordeiro, Pérez & Castro, 2015 (MNRJ 8566, holotype); E–F: polyps of Radicipes gracilis (Verrill, 1884) 
(BMNH 1889.5.27.4, holotype, including detail of the oral portion (E’), of Radicipes fragilis (Wright & Studer, 1889) and, 
USNM 8877, syntype of Radicipes gracilis (Verrill, 1884)), respectively; G: polyp of Radicipes aureus Kükenthal, 1919 (ZMB 
8565, holotype); H, H': polyp of Radicipes pleurocristatus Stearns, 1883 (BMNH1889.5.27.2, holotype of Radicipes verrilli
(Wright & Studer, 1889)) and detail of the oral portion, respectively; I, I': polyps of Radicipes pleurocristatus Stearns, 1883 
(USNM 49464), full-sized polyps, normal and fertile, respectively. Scale bars: A, H': 0.2 mm; B: 0.6 mm; C: 0.5 mm; D, E, G, 
H, I’: 1 mm; D', E’, F: 0.5 mm. Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  5REVISION OF RADICIPES 
FIGURE 3. Distributional range of Radicipes records based on localities of the specimens herein examined (orange circles) as 
well as geo-referenced data compiled from literature (Williams, 1992; Mortensen et al., 2007; Altuna, 2010; Watling et al., 
2011; Rueda et al., 2012; Alderslade et al., 2014; Gonzalez-Mirelis & Buhl-Mortensen, 2015) and the Ocean Biogeographic 
Information System—OBIS (yellow circles). 
Radicipes pleurocristatus Stearns, 1883
Figs. 1B,C,E, 2H –I’, 4, 5
Radicipes pleurocristatus Stearns, 1883: 97–98, pl. 7, figs. 1–2.—Kinoshita, 1913: 5–8, pl. 3, figs. 1–2, text-figs. 1–3.—
Kükenthal, 1919: 542–543; 1924: 410–411 (key to species).—Bayer, 1961: F218, text-fig. 156, 3a–d; 1979: 882, fig. 2b.—
?Fujita & Ohta, 1988: 2019–2042, figs. 1–6, in part (brittle star commensals).—?Fujita, 2001: 267, fig. 3a–c, in part 
(brittle star commensal).—Matsumoto et al., 2007: 241 (listed).—Cordeiro, et al., 2015: 95 (tabular key to species). 
Strophogorgia verrilli Wright, 1885: 691 (nom. nud.).
Strophogorgia verrilli Wright & Studer, 1889: 3, pl. 1, fig. 2, pl. 5a, fig. 3.
Strophogorgia petersi Wright & Studer, 1889: 2–3, pl. 2, fig. 1, pl. 5a, fig. 1.
Lepidogorgia petersi.—Versluys, 1902: 7–12, text-figs. 4–14.—Thomson & Henderson, 1906: 27 (tabular key to species).—
Nutting, 1912: 53.
Lepidogorgia verrilli.—Versluys, 1902: 12–14, text figs. 15–17.—Thomson & Henderson, 1906: 26–27, pl. 3, fig. 5 (tabular 
key to species).—Not Thomson, 1927: 20–21 (=R. gracilis).
Radicipes verrilli.—Kükenthal, 1919: 543; 1924: 411 (key to species).—Fujita, 2001: 267–272, figs. 3, 5, 6 (brittle star 
commensal).—Matsumoto et al., 2007 (listed).—?Stone & Shotwell, 2007: 107 (listed, Alaska).—Cairns et al., 2009 
(listed for New Zealand).— Cordeiro et al., 2015: 95 (tabular key to species).
Types and type localities. Radicipes pleurocristatus: USNM 5685 (syntype, eight dry fragments), Japan, depth 
unknown (specimens purchased from a fisherman in Enoshima (=Sagami Bay)).
Strophogorgia verrilli: BM 1889.5.27.2. Type Locality: Chall-235, 34°07'N, 138°00'E, 1033 m (off Japan, 
syntypes); and Chall-237, 34°37'N, 140°32'E, 3429 m (not found).
Lepidogorgia petersi: Types were not found at the BMNH and are presumed to be lost. Type Locality: Chall-
232, 35°11’N, 139°28’E, 631 m (off Chiba Peninsula, Japan).
Material examined. Alb-4969, 33°23'40"N, 135°33'E, 1073 m (USNM 49464 and USNM 50095); Alb-4971, 
33°23'40"N, 135°34'E, 1187 m (USNM 49465); Alb-4976, 33°02'50"N, 135°38'30"E, 994-997 m (USNM 30070); 
Alb-4958, 32°36'20"N, 132°24'30"E, 741 m (USNM 57487); Alb-5605, 00°21'33"N, 121°134'10"E, 1183 (USNM 
49899); Alb-5648, 5°35'03"N, 122°20'E, 1022 m (USNM 49966).CORDEIRO ET AL.6  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press
FIGURE 4. Sclerites of Radicipes pleurocristatus Stearns, 1883 (USNM 49464) A: rods from the body wall; B: detail of a rod 
from the body wall; C: coenenchymal scales; D: pinnular scales; E: tentacular rods. Scale bars: A: 0.5 mm, B,D-E: 0.02 mm, C: 
0.2 mm. Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  7REVISION OF RADICIPES 
FIGURE 5. Sclerites of Radicipes pleurocristatus Stearns, 1883 (BMNH1889.5.27.2, holotype of Radicipes verrilli (Nutting, 
1908)). A: rods from the body wall; B: tentacular rods; C: coenenchymal scales; D: pinnular flattened rods. Scale bar: 0.2 mm.CORDEIRO ET AL.8  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press
Description. Colonies fragile and brittle, light brown in color or completely white, with an iridescent aspect. 
Minimum axis diameter of 0.4 mm in most of the specimens examined; maximum of 4.3 mm. Axis stiff, clockwise 
helicoidal in basis-apex direction, slightly elliptical in cross-section. Axial diameter decreasing in basis-apex 
direction. Calcareous holdfasts with root-like projections, usually thicker than axis. Polyps arranged in a single 
longitudinal line (polypar side), corresponding to the external face of axis. Polyps cylindrical or trumpet shaped, 
vertically or obliquely oriented, 2.8 to 5.1 mm long in those fully developed (Fig. 2H–I’). Wider saddle bags and 
oral portions in fertile polyps (Fig. 2I’). Polyps closely placed, in number four per centimeter in proximal portions, 
separated by about 1.4 mm, and well spaced in distal parts with one polyp per centimeter and up to 6.0 mm 
between. Usually three polyps per centimeter. Some specimens (e.g., USNM 30070) with perpendicularly-oriented 
polyps. In distal portion, both polyps and sclerites thinner and smaller. Abaxial portion of fully developed polyp 
filled with longitudinally-oriented rods as long as entire body wall, 0.6 to 2.3 mm in length, and from 0.04 mm to 
0.16 mm in width (Fig. 4A, 5A). Rods cylindrical to slightly flattened or with flattened tips (rare) (Fig. 4B). 
Adaxial portion of polyps with fewer developed sclerites, fewer in number. Fully developed polyps with flattened 
sclerites in a structure resembling a saddle bag and usually curved rods transversely or irregularly arranged, 
forming a bulb-like base (Fig. 2I’); infertile or not completely developed polyps lack saddle bag and transversely 
arranged sclerites (Fig. 2H). Coenenchymal scales long, longitudinally curved and usually disposed in a single 
layer, along entire colony on polypar and abpolypar faces, 0.15 to 1.0 mm long, and 0.04 mm to 0.12 mm wide, 
rarely reaching the length of the rods from the body wall (Fig. 4C, 5C). Coenenchymal scales smaller in abpolypar 
side and absent on polypar line, where body wall rods cover the spaces between fully developed polyps. Tentacular 
rods one quarter to one-fifth the length of those in body wall, 0.2–0.46 mm long and 0.02–0.1 mm wide (Figs. 4E, 
5B). Flattened pinnular rods 0.09–0.26 mm long and 0.01–0.05 mm wide (Figs. 4D, 5D). 
Remarks. The syntypes consist of eight fragments, including four holdfasts, indicating at least four specimens, 
with the largest fragment 32 cm long and 4.3 mm in diameter but with only 14 polyps remaining. One of the 
specimens examined (USNM 57487) is very slender, with well spaced polyps, lacking transverse infrabasal 
sclerites, irregular rods, also lacking curved sclerites in coenenchyme.
Kükenthal (1919) mistakenly described R. pleurocristatus as having naked lateral walls and Cordeiro et al.
(2015) compiled this information in their table of valid species of Radicipes. In fact, there are no naked polyp parts 
in R. pleurocristatus. As did Cordeiro et al. (2015), we also provide a tabular key of valid species, but mainly based 
on the examination of types (Table 1).
We did not examine the type of Strophogorgia petersi Wright & Studer, 1889, but the illustrations of the type 
given by Versluys (1902) and the distribution pattern match R. pleurocristatus (e.g., Versluys, 1906, p. 8–11, figs. 
4–13). We also accept Radicipes verrilli (Wright & Studer, 1889) as a junior synonym of R. pleurocristatus, as 
previously implied by Versluys (1902) and Kükenthal (1919). Additionally, these species have the same 
distribution patterns. The basic difference between the types of R. pleurocristatus and R. verrilli was based on a 
more slender shape of the polyps in R. verrilli and a body wall filled only with longitudinally arranged rods (Fig. 
2H,H’), whereas R. pleurocristatus has longer body wall rods and a basal bulb (saddlebag) in most of the polyps, 
giving it a more robust appearance (Fig. 2I,I’). It is likely that the development of the bulb-like portion is directly 
related to the sexual maturation of the polyp, as well the enlargement of the oral portion, as most of the studied 
species showed eggs in the basal portion of their robust polyps. There is no information in the literature to indicate 
the reproductive features in species of Radicipes or any other chrysogorgiid. Thus we cannot discard the possibility 
of sexual dimorphism among colonies or even within polyps of a single colony. Finally, it is worth mentioning the 
common association of this species with white brittle stars of the genus Asteronyx (Fujita & Ohta, 1988). 
Distribution. Eastern Pacific (Japan) to Indo-Pacific (Indonesia), 629 to1301 m.
Radicipes stonei sp. nov. 
Figs. 2C, 6
Radicipes verrilli.—Stone & Shotwell, 2007: p. 107, Appendix 2.1 (table).
Radicipes sp.—Watling et al., 2011: p. 47, fig. 2.2G–H, p. 70, fig. 2.5.
Types. Holotype: J2105-4-1 (USNM 1418007). Paratypes: J2096-6-1, 52°23’34.2"N, 174°53’3.24"W, 2153 m 
(USNM 1418006, one specimen); JD-092, 53°27’12”N 163°23’22”W, 3580 m (Derickson Seamount, Aleutian  Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  9REVISION OF RADICIPES 
Islands) (USNM 1081191, one specimen); JD-093 53°00’53”N 161°14’35”W, 3179 m (Derickson Seamount, 
Aleutian Islands) (USNM 1081144, one specimen).
Type Locality. 51°53’12.18"N, 178°21’27.18"W (northwest of Tanaga Island, Aleutian Islands), 2107 m.
FIGURE 6. Sclerites of Radicipes stonei sp. nov. A: rods from body wall; B: tentacular rods; C: coenenchymal scales; D: 
flattened pinnular rods. Scale bars: A: 0.2 mm; B: 0.05 mm; C: 0.1 mm; D: 0.02 mm.
Description. Colonies white, delicate, golden-iridescent aspect and coiled both clockwise or counterclockwise 
in ascendant direction. Axis 2.9 mm maximum diameter. First one-third of colonies (up to 12 cm) usually without 
polyps. Polyps 1.0–3.0 mm long, inclined 45° to 90° in relation to axis, linearly disposed on only one side of 
colony, in a frequency of about three polyps per centimeter, spaced 2.0–5.0 mm from each other, but ranging from 
one to five polyps per centimeter. Density of polyps decreasing toward branch tip and distance between polyps 
increasing in the same direction. Body wall of polyps with rods, longitudinally arranged, some with a flat end and CORDEIRO ET AL.10  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press
(rarely) completely flattened (scale-like), 0.13–0.86 mm long and 0.03–0.10 mm wide (Figs. 2C, 6A). Adaxial side 
with large supporting curved rods, with slightly flattened and rounded tips. Outer lateral side with flattened rods, 
half the length of abaxial supporting rods. Size of rods decreasing toward the oral portion of tentacles. Inner lateral 
and adaxial side with sparse flattened scales with almost blunt tips, sometimes naked. Coenenchymal scales 
longitudinally grooved and with at least one flattened tip, longitudinally arranged, uniformly surrounding axis from 
base to polypar portion (except in juvenile colonies), gradually changing in length and form in the same direction. 
Basal coenenchymal scales larger, more deformed and more tuberculate than those from polypar portion, 0.15–0.68 
mm long and 0.05–0.12 mm wide (Fig. 6C). Juvenile specimens with four to eight longitudinal sclerite rows along 
the coenenchyme. In basal sterile portion, short scales and rods present, oval or waisted (8-shaped) in shape. In 
polypar portion scales are as long as the rods from the body wall. In polypar line, rods from the body wall 
frequently connect coenenchyme between two adjacent polyps. Tentacular rods smaller with slightly flattened 
ends, 0.14–0.3 mm long and 0.02–0.06 mm in width (Fig. 6B). Pinnular rods completely flat, with ridges and 
serrate margins, 0.06–0.14 mm long and 0.01–0.04 mm wide (Fig. 6D).
Comparisons. Along with R. pleurocristatus and R. aureus, this species shares the longest polyps and body 
wall sclerites in the genus. Colonies of R. stonei sp. nov. are quite delicate, but their polyps are similar to those of 
R. pleurocristatus in general aspect (especially in comparison with the holotype of R. verrilli). The ratio between 
the maximum length of the polypar and coenenchymal sclerites is another distinctive feature. In R. pleurocristatus, 
the length of the coenenchymal sclerites never reaches more than half that of those from the body wall, whereas in 
R. stonei sp. nov. they are nearly the same size. Radicipes pleurocristatus can also have slightly flattened short rods 
close to the base, transversely or irregularly arranged, whereas R. stonei sp. nov. has only scales longitudinally 
disposed. The latter has less sculptured coenenchymal scales with more regular margins and with at least one much 
flattened tip. Furthermore, the two species colonize different bathymetric ranges (Table 1).
Etymology. Named in honor of Robert P. Stone, coral and sponge authority of the Alaskan region.
Remarks. This species was probably photographed during NOAA cruises in the Aleutian Ridge, forming 
dense meadows in muddy bottoms, and this record is already mapped and available in the literature (see Watling et 
al., 2011, p. 47, fig. 2.2G. and p. 70, fig. 2.5). The species was first recorded at the location as R. verrilli by Stone & 
Shotwell (2007). 
DNA sequences obtained from the holotype (USNM 1418007) for COI+igr+msh1 are similar to the specimen 
sequenced by McFadden et al. (2011) and Pante et al. (2012) from station J209661 (Alaska: uncorrected p-distance 
= 0.07%) (see GenBank accessions KY748360 and KY748361, unpublished data). Analyses made by the authors 
mentioned above show an isolation of the Alaskan lineage, supporting the establishment of the new species. 
Genetic distances (uncorrected-p) of R. stonei sp. nov. to other non-Alaskan Radicipes sequences range from 
0.21% to 0.92% (unpublished data).
The morphological similarity as well as the closeness with the geographical range of R. pleurocristatus
indicate that these two species may have a common origin. In fact, the analyses by Pante et al. (2012) (e.g. NIWA 
28821, NIWA 45304 and NORF47/2-NIWA) show a common origin of Radicipes species from Alaska (R. stonei
sp. nov.), Solomon Islands, Western Australia, New Caledonia and New Zealand. 
If we consider one of the specimens sequenced by Pante et al. (2012) as being R. pleurocristatus, there is at 
least one more undescribed species inhabiting the Indo-Pacific.
Distribution. Gulf of Alaska (Derickson Seamount) and Aleutian Islands, 1207–3580 m.
Radicipes spiralis (Nutting, 1908)
Fig. 7
Lepidogorgia spiralis Nutting, 1908: 588, P. 45, fig. 5.
Radicipes spiralis, Kükenthal 1919: 549.—Grigg & Bayer, 1976: 172, tab. 2 (listed).—Parrish & Baco, 2007: 188, Appendix 
4.1. (listed).—Watling et al., 2011: 66, tab. 2.2 (listed). 
Types and Type-locality. Syntypes: USNM 25355 (one colony and four fragments) and USNM 22558 (three small 
fragments), Alb-4103, 21°02'20"N, 156°46'20"W, 241–258 m (Hawaii).
New record. Okeanos Station D2-EX1504-L2-16, 25°38'37.32"N, 168°50'49.2"W, 1462 m, photo only—no 
specimen, thus record not confirmed (Fig. 1A,D). ? Alb-3989, 22°06’55”N, 159°16’51”W, 704–914 (USNM 
1438878). Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  11REVISION OF RADICIPES 
Description. Brittle colonies, slightly flexible in mid and terminal portions, coiled in clockwise ascendent 
manner from base to apex. Axis diameter from 0.2 mm to 1.3 mm. Presence of non-horny nodes at proximal 
portion of larger colony. Polyps 1.2 to 3.2 mm long, uniserially and longitudinally distributed, two to four polyps 
per centimeter (usually three), with 0.3 mm to 2.0 mm distance between polyps. In their distal portion, polyps 
juxtaposed with almost no space between. Polyps completely naked or covered with sparse body wall rods that lack 
order, 0.15–0.25 mm long and 0.01–0.03 mm wide (Fig. 7). Tentacular and pinnular flattened rods, when present, 
0.08–0.15 mm long and 0.01–0.03 mm wide. Coenenchymal sclerites rare or completely absent. Some areas of axis 
with tiny isolated, flattened rods embedded in coenenchyme. Presence of many micro-silicoclastic inclusions in 
tentacles of some polyps. 
Comparisons. There are no species in the genus similar to R. spiralis. The virtual absence of sclerites in the 
body wall and the delicate nature of the colonies resemble in some ways the Atlantic species Radicipes challengeri
(Wright & Studer, 1889) and Radicipes kopelatos Cordeiro, Castro & Pérez, 2015. However, R. spiralis is the only 
species with no conspicuous sclerites.
Remarks. The syntype consists of brittle basal fragments and one entire colony without a holdfast collected 
from a single station (Albatross 4103). Although the original description (Nutting, 1908) of this species mentions 
no sclerites, with some effort it is possible to find some rods in the body wall. 
An additional specimen (USNM 1438878), named Radicipes sp., resembles the general morphology of R. 
spiralis, with a virtually naked body wall (Fig. 8A), however its “saddle bag” region is densely filled by flattened 
rods and scales, usually with a low, irregular longitudinal ridge (Fig. 8B). The tract between two full-sized polyps 
might have a narrow line of the same sclerites from saddle bag region (Fig. 8A). The mentioned specimen was 
collected in Hawaii by the USFWS Albatross (sta. 3989), several kilometers from the type locality of R. spiralis. 
Due to the lack of colonies with intermediate morphological features between the latter and Radicipes sp., we 
consider it inadequate to adjust the diagnosis of R. spiralis to include this specimen. Descriptions made by C. C. 
Nutting are often challenged and must be considered with caution.
FIGURE 7. Sclerites of Radicipes spiralis (Nutting, 1908) (Syntype): rods from body wall. Scale bar: 0.05 mm.CORDEIRO ET AL.12  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press
FIGURE 8. Polyp and sclerites of Radicipes sp. (USNM 1438878). A: polyp without conspicuous sclerites surrounded by a 
saddle bag filled with flattened rods and scales; B: scales and flattened rods. Scale bars: A: 0.2 mm; B: 0.1 mm.
Since its original description, no new collections of R. spiralis have been made. Thus, all subsequent 
publications about this species are simply compilations of Versluys’ (1902) statements. 
Today the area where this species occurs belongs to the Papahānaumokuākea Marine National Monument, the 
world’s largest marine protected area. Recent NOAA deep-sea surveys visually documented several chrysogorgiid 
communities in Hawaii (please visit http://oceanexplorer.noaa.gov/okeanos), including colonies of Radicipes (Figs. 
1A,D), which could be R. spiralis or Radicipes sp. (as discussed above). If the identification is R. spiralis, the 
deepest bathymetric record of that species would be extended from 257 to 1462 m. Only future collection efforts 
will better characterize this species and test this hypothesis. 
Distribution. Known only in the type locality, 241–?1462 m depth. Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  13REVISION OF RADICIPES 
Radicipes gracilis (Verrill, 1884)
Figs. 2E–F, 9, 10
Lepidogorgia gracilis Verrill, 1884: 220; 1885: 512, 533, pl. 2, fig. 10, 10a.—Versluys, 1902: 16.—Thomson & Henderson, 
1906: 27 (tabular key).
Strophogorgia fragilis Wright & Studer, 1889: 4, pl. 2, fig. 2, pl. 5a. fig. 4.
Lepidogorgia fragilis.—Versluys, 1902: 16-17.—Thomson & Henderson, 1906: 27.
Radicipes gracilis.—Kükenthal, 1919: 548; 24: 412.—Verrill, 1922: 42, fig 10, 10a.—Deichmann, 1936: 237.—Madsen, 1944: 
46–49, text-figs. 37–41.—Bayer, 1979: 882, fig. 2c.—Bayer & Macintyre, 2001: 342 (mineralogy).—Watling & Auster, 
2005: 28 (listed).—McFadden et al., 2006: 525, figs. 1–3.—Wareham & Edinger, 2007: 295, 298, 302, fig. 1J.—Cogswell 
et al., 2009: fig. 10G.—Buhl-Mortensen et al., 2010: 43 (mentioned). —Pante & France, 2010: 597.—Watling et al., 2011: 
59 (listed).—Baker, et al., 2012: 239, 240, 244.—Pante & France, 2012: figs. 2–3, supplemental table 1 (listed).—
Cordeiro et al., 2015: 94, 95 (tabular key).—Buhl-Mortensen et al., 2015: 39–61, figs. 2f, 3i, 4, 5.
?Lepidogorgia challengeri.—Jungersen, 1915: 1184.
Radicipes fragilis.—Kükenthal, 1924: 143. —Tixier-Durivault & d’Hondt, 1975: 1410. —Braga-Henriques et al., 2013: 4026 
(listed).—Cordeiro et al., 2015: 95 (tabular key).
Lepidogorgia verrilli.—Thomson, 1927: 20–21, pl. 3, fig. 18, pl. 5, fig. 20.
Types and Type Localities. Radicipes gracilis: USNM 9118 (syntype), Alb-2072 , 41°53'N, 65°35'W (off 
Massachusetts), 1569 m; USNM 8877, USNM 9350, USNM 26030, USNM 30283, USNM 33570, YPM 8768 and 
YPM 10045 (syntypes), Alb-2037, 38°53'N, 69°23'30"W, 3166 m (off Massachusetts); part of the syntype series 
(from Alb-2036) is lost.
Strophogorgia fragilis: BM 1889.5.27.4 (holotype, one specimen), Chall-70: 38°25’N, 35°50’W (west of 
Azores), 3063 m.
Material Examined. Del-23, 39°55'55"N, 67°11'W, 1155 m (USNM 1111944, YPM 35442 and YPM 36838); 
Alb-2569, 39°26'N, 68°03'30"W, 3259 (USNM 11913 and YPM 10049); Del-29, 39°53'N, 67°23'W, 1395 (USNM 
1110402); Alb-2209, 39°34'45"N, 71°31'30"W, 1975 m (USNM 8193 and YPM 10051); Alb-2570, 39°54'05"N, 
67°05'30"W, 3316 m (USNM 11914); Alb-2575, 41°07'N, 65°26'30"W, 3128 m (USNM 11908); Alb-2563, 
39°18'30"N, 71°23'30"W, 2601 m (USNM 11929 and YPM 10106); Del-14, 39°53'N, 67°26'24"W, depth unknown 
(USNM 100900); Del-47-Bear, 39°52'58"N, 67°25'58"W, 1195-1402 (USNM 1010390); Del-24, 39°52'12"N, 
67°20'18.6"W, 1428–1650 m (YPM 36783); Pisces-16, 40°10'54"N, 67°26'40.2"W, 1961 m (YPM 72083).
Description. Colonies golden, stiff, tall, up to 90 cm in height, coiled in clockwise or counterclockwise 
manner; axis 2.2 mm, maximum diameter. Young colonies brittle and iridescent. Holdfast calcareous, profusely 
branched, usually thinner than axis. Coenenchyme thin, fragile and easily detachable from axis. At least one 
quarter of lower part of colony devoid of polyps. Distance between polyps about 1.5 mm in proximal portions to 
10.0 mm distally. Polyps 2.5–5.0 mm long, cylindrical to slightly trumpet-shaped (Fig. 2E–F), disposed in a single 
longitudinal line (polypar side), spaced 4.0–10.0 mm apart in a frequency of three to five per centimeter (usually 
three). Eight longitudinal rows of rods in the body wall of completely developed polyps, with adaxials usually less 
developed, 0.18–0.7 mm long and 0.02–0.06 mm wide. Longest rods of body wall aligned with abaxial side, but no 
large supporting rods in abaxial side. Abaxial line from the lower portion of polyp to distal portion with four to six 
juxtaposed pairs of rods in alternate lines, relatively homogeneous in size. Sclerite size decreases from abaxial to 
outer lateral rows. Inner lateral and adaxial rows composed of loosely placed rods, sometimes naked. Oral portion 
with rods similar in size to those from lower portion of polyp. Infrabasal and adaxial portions filled with flattened 
rods, slightly 8-shaped, 0.15–0.26 mm long and 0.04–0.05 mm wide (Figs. 9A, 10A). Infrabasal and abaxial rods 
with slightly flattened tips becoming more rounded and sparse in oral portion. Abaxial row of rods extending 
through coenenchyme between polyps, connecting them. Coenenchymal sclerites rare or completely absent, when 
present, similar to those of infrabasal and adaxial portions. Tentacular rods 0.07–0.18 mm long and 0.01–0.04 mm 
wide, becoming flatter in proximal-distal wall (Figs. 9B, 10C). Pinnules filled with small scales, 0.1–0.13 mm in 
length and 0.01–0.04 mm in width (Figs. 9C, 10B).
Comparisons. Colonies of R. gracilis differ from the Atlantic species R. challengeri and R. kopelatos by 
having larger polyps (Table 1) and by having their body wall densely filled with sclerites (Fig. 2). Although the 
longest polyps in R. kopelatos reach up to 3.3 mm, most polyps in a colony are very short in comparison to those in 
R. gracilis, usually half their length. As well, the axis diameter in R. gracilis is usually thicker. The Pacific species 
Radicipes stonei has a similar polyp shape, but differs in having one or two long supporting rods in the lower 
abaxial side, having irregular infrabasal flattened rods, and having body wall rods with at least one flat tip.CORDEIRO ET AL.14  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press
FIGURE 9. Sclerites of Radicipes gracilis (Verrill, 1884) (USNM 8877, syntype). A: rods from polyp body wall; B: flattened 
tentacular rods; C: pinnular scales. Scale bars: A, B: 0.1 mm; C: 0.05 mm. Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  15REVISION OF RADICIPES 
FIGURE 10. Sclerites of Radicipes gracilis (Verrill, 1884) (BMNH1889.5.27.4, holotype of R. fragilis (Wright & Studer, 
1889)). A: rods from body wall; B: pinnular scales; C: tentacular rods. Scale bars: A,C: 0.1 mm; B: 0.05 mm.CORDEIRO ET AL.16  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press
Remarks. Radicipes gracilis is the most frequently recorded species in the genus, with at least 12 records 
presented herein and several others gleaned from the literature (Fig. 3, Supplementary file). Most studies have 
treated mid-Atlantic (R. fragilis) and western Atlantic (R. gracilis) populations as separate species. Nonetheless, no 
revisions including examinations of both types have been carried out until now. The type remains of R. fragilis
consist of just a fragment of tissue (no axis) with several polyps. But this is enough to determine that the types are 
indistinguishable (compare Fig. 2E,E’ with 2F and Fig. 9 with Fig. 10). Several misconceptions about the 
morphological features of R. gracilis can be seen in the available literature. Thomson & Henderson (1906), for 
example, implied that the species has more coenenchymal sclerites than R. pleurocristatus (see Thomson & 
Henderson, 1906: p. 27, comparative table of species of Lepidogorgia). According to Madsen (1944) and Cordeiro 
et al. (2015), the main differences between the two species can be seen in the measurements of the polyps, twice as 
long in R. gracilis, and the longer body wall rods in R. fragilis (Cordeiro et al., 2015). We understand that the 
‘polyp distinction’ is due to the measurements given by Madsen (1944), which included tentacles in the total polyp 
length determination, whereas no other author has included the tentacles to describe this character. Actually, both 
species have the same polypar length range, from 2.5 to 4.0 mm, not 5.0 to 10.0 mm as stated by Madsen. Rods 
from the body wall were slightly longer in the R. fragilis type (up to 0. 75 mm long, whereas usually just up to 0.5 
mm in western Atlantic specimens). Even though we only examined one mid-Atlantic colony, we consider it to be 
the same species, considering the sclerite size to be more related to age of the colony and sexual maturation. 
It remains to be seen if the sequenced mid-Atlantic specimen ‘VER2041’ (Pante et al., 2012) fits our R. 
gracilis definition, or R. challengeri, or is a different species. Considering Pante’s phylogenies, in the first case, 
one could consider treating R. gracilis as a cryptic species complex or one could suggest the reestablishment of R. 
fragilis as a valid name. Our examinations however do not allow us to keep both as valid.
Distribution. In western Atlantic from North Carolina to Canada; Mid-Atlantic Ridge, Seamounts and 
Portugal (Azores), from 500–3259 m.
Radicipes challengeri Wright & Studer, 1889
Figs. 2A,B , 11, 12
Strophogorgia challengeri Wright, 1885: 691 (nom. nud.). 
Strophogorgia challengeri Wright & Studer, 1889: 3–4, pl. 1, fig. 1, pl. 5a, fig. 2.
Lepidogorgia challengeri: Versluys, 1902: 14–15, text-figs. 18-18-19.—Thomson & Henderson, 1906: 27 (tabular key).—
Thomson, 1927: 20, pl. 4, fig. 17.
Radicipes challengeri: not Jungersen, 1915: 1183–1184 (=R. gracilis).—Kükenthal, 1919: 543–544; 1924: 411–412.—not 
Kramp, 1932: 10.—Deichmann, 1936: 237.—Madsen, 1944: 44–46, text-figs. 33–37.—Watling & Auster, 2005: 294 
(listed).—Altuna, 2010: 10.—Watling et al., 2011: 59 (listed).—Cordeiro et al., 2015: 95 (tabular key).
Types and Type Locality. BMNH 1889.5.27.3 (holotype, several fragments); Chall-4, 36°25’N, 8°12’W (off 
Cadiz, Spain), 1097 m.
Material Examined. Ger-142, 24°28'N, 80°12'W, 805 (USNM 57314); Pill-586, 23°32'N, 82°33'W, 1682-
1737 (USNM 57317); Or-1341, 22°55'N, 79°16'W, 439 (USNM 50184).
Description. Colonies delicate, coiled in a clockwise manner towards the tip, with a calcareous and delicate 
holdfast. Axis with a maximum diameter of 0.75 mm. Small polyps, 0.7 to 1.7 mm long (Fig. 2A,B), disposed in a 
single line, 1.5–4.0 mm apart. Polyps with more conspicuous sclerites on abaxial and outer lateral sides, more 
conspicuous distally. Body wall filled with slightly to completely flattened rods, being more flattened on polyp 
base, tentacles and in adaxial rows, more rounded in abaxial rows. Body wall rods longitudinally arranged and 
fairly uniform in length, being slightly longer near oral portion, 0.15–0.53 mm long and 0.02–0.06 mm in width 
(Figs. 11A, 12A). Infrabasal sclerites rare or absent, slightly to completely flattened, variable in size, immersed in a 
dense coenenchyme, appearing as a naked base. Tentacular rods homogeneous in size (Figs. 11C, 12B), 0.15–0.35 
mm long and 0.02–0.03 mm in width, with length equal to or smaller than those from the base, distally becoming 
rare or absent. Pinnular sclerites also sparse towards the tips of tentacles, 0.1–0.15 mm long and 0.02–0.04 mm in 
width (Fig. 11B). Adaxial side of polyps naked or with few conspicuous sclerites. Spaces between polyps 
completely naked in both polypar and abpolypar faces of the colony. Coenenchymal sclerites rare or absent. When 
present, coenenchymal sclerites are 8-shaped scales. Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  17REVISION OF RADICIPES 
Comparisons. Radicipes challengeri is one of the species in the genus having few sclerites, but not essentially 
absent as in R. spiralis, and has the smallest polyps of those in the genus. Morphologically, the most closely-related 
species is R. kopelatos (southwestern Atlantic), but the species described here is distinguished from R. kopelatos by 
showing rare or no coenenchymal sclerites, by not having rods in the body wall in the coenenchyme between 
polyps, and less conspicuous and more flattened body wall rods. Young parts (terminal portions of branch) in R. 
gracilis might be confused with colonies of R. challengeri by showing inconspicuous sclerites in the body wall of 
polyps.
Remarks. Of all available western Atlantic records of Radicipes, only three match the eastern Atlantic type of 
R. challengeri. This is the first record of this species in the western Atlantic. However, western Atlantic specimens 
have slightly more conspicuous body wall rods and infrabasal sclerites surrounding the axis beneath the polyp.
There are no recent eastern Atlantic records of R. challengeri, but it is possible that most of the records 
published as Radicipes sp. belong to this species (see Distribution section under genus Radicipes). It remains to be 
determined which species correspond to the West African record (see Fig. 3).
FIGURE 11. Sclerites of Radicipes challengeri (Wright & Studer, 1889) (BMNH1889.5.27.3, holotype). A: rods from body 
wall; B: pinnular scales; C: tentacular rods. Scale bars: A: 0.1 mm; B–C: 0.05 mm.CORDEIRO ET AL.18  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press
FIGURE 12. Sclerites of Radicipes challengeri (Wright & Studer, 1889) (USNM 57314). A: rods from body wall; B: rods 
from tentacles. Scale bar: 0.1 mm.
It is not unusual to find amphi-Atlantic coral species, especially in groups restricted to deep waters. Known 
examples that demonstrate this geographic pattern include scleractinians (Cairns & Chapman, 2001), octocorals 
(Pires & Castro, 2010) and possibly chrysogorgiids (Grasshoff, 1981; Cairns, 2001). Braga-Henriques et al. (2013: 
4024) also argued that 35 % of the deep-water coral species occurring in the central northeast Atlantic (Azores) 
have amphi-Atlantic distributions; these authors found depth-related trends of faunal change in their dataset, i.e. the 
proportion of amphi-Atlantic species increased from 19% at at 100–600 m to 23% at the 1000–1500 m. The 
scarcity of data makes it difficult to understand how these populations were connected in the past. Lastly, as occurs  Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  19REVISION OF RADICIPES 
in the scleractinian Lophelia pertusa (see Goff-Vitry et al., 2004), it is even possible that eastern and western 
Atlantic populations of R. challengeri form a complex of cryptic species.
Distribution. Western Atlantic: Straits of Florida and Cuba; Eastern Atlantic: Iceland and Portugal (mainland), 
439–1737 m.
Radicipes kopelatos Cordeiro, Castro & Perez, 2015
Figs. 2D, 13
Radicipes kopelatos Cordeiro, Castro & Perez, 2015: 94–96, figs. 2H, 8–9.
Radicipes sp.1: Castro et al., 2006: 170 (listed).
Radicipes sp. 2: Castro et al., 2006: 170 (listed)
Types and Type Locality. MNRJ 8566 (holotype), Thal-464, 21°48’49”S, 40°01’53”W, 592.4–618.8 m (off Rio 
de Janeiro) .
Material Examined. Paratypes: Thal-522, 13°22’17”S, 38°36’56”W, 750 m (MNRJ 5968, three colonies); 
MNRJ 4361, same collection data as that of the holotype (55 colonies). 
Description. Colonies flexible, white or yellowish, with clockwise or counterclockwise upward spiraling 
trend, up to 60 cm long. Axis with iridescent aspect, 0.7–1.0 mm diameter, calcareous holdfast with projections up 
to 6.0 mm long. Coenenchyme easily detachable from axis. Polyps 0.8–3.5 mm long (Fig. 2D), disposed in a single 
row, 1.0–4.0 mm distant from each other, in a frequency of two to five polyps per centimeter, but usually four. 
Frequency of polyps usually decreasing in base to apex direction, with up to five polyps per centimeter on the 
proximal two-thirds of the colony, two to four polyps per centimeter on the distal third. Body wall with rods 0.16–
0.60 mm long, longitudinally arranged, homogeneous in diameter (0.03–0.08 mm), sometimes flattened, usually 
with flattened ends, sparse in some areas of the colony (Fig.13A). Coenenchymal scales (8-shaped) 0.15–0.25 mm 
long (Fig. 13B) and 0.03–0.07 mm in width. Sclerites on abpolypar face rare or absent except on polyp bases. 
Adaxial and infrabasal portion of polyps frequently filled with scales similar to those of coenenchyme, slightly 
smaller than the spindles, 0.10–0.18 mm long. Rods from tentacles longitudinally striated and slightly constricted, 
sometimes twisted in the middle, 0.08–0.12 mm long and 0.02–0.04 mm in width (Fig. 13C). Pinnular sclerites 
represented by small scales, 0.1–0.14 mm long and 0.02–0.04 mm wide (Fig. 13D).
FIGURE 13. Sclerites of Radicipes kopelatos Cordeiro, Castro & Pérez, 2015 (MNRJ 8566, holotype). A: rods from polyp 
body wall; B: coenenchymal 8-shaped scales; C: tentacular rods; D: pinnular scale. Scale bar: 0.15 mm.CORDEIRO ET AL.20  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press






	




	












	








R
ad
ic
ip
es

















































































	



 
 !










"
	









#
!














R
ad
ic
ip
es
 a
ur
eu
s


$

	

%

 
 



R
ad
ic
ip
es
 
ch
al
le
ng
er
i
&

	
%

'
'(


Ra
di
ci
pe
s 
gr
ac
ili
s

)


%


''
*!


R
ad
ic
ip
es
 
ko
pe
la
to
s 
+



%

,
-
.


/

+


%

0
1
(

R
ad
ic
ip
es
 
pl
eu
ro
cr
is
ta
tu
s

2


%


''
3

Ra
di
ci
pe
s 
sp
ir
al
is


4


%


 1
'!
Ra
di
ci
pe
s 
st
on
ei
 




5


6


















!


1#


1
7(


0
0


1

*
3


3

0
 

,





	



!

3
1

8(
1
#

1
78

7

0
(8
(

1
'8
3
(

0
'8
(



08
3
0


18
3
1

4








9












!

08
3

3
!#



:


"


38
(

3
!

08
(

*
!

8
*

3
!

08
*

3
!

8
(

3
!

+



	










,




;

9





;

9





,




,




;

9





,



















	










<












	




%

5



"








=





>











"




 l

.







=






"








"






.







:


























>


?






"







"








<














%






"









	




.





%
"
	






"








5


	







"



	



=





>











"






.





<











	




%






"









	





.





%

"
	






"








5


	








"



	



2	





	







	










2



"
	












'
	




'
	




'
	




@










5








"








!


A










2













5
%

"
	




















@


	







	












!

@B
&
!

1
08
1
C

(
8C
!



1
(
81
0
C


3
7
(8
(
0!


1
(
81
0
(


3
C
8(
!

1
(
8
1

3
7
(8
'
3!




1
(
81
C
'

3
8(
7
!

D












"









2













































%








































5








?









;
































;

















2






















!


;

































%































5














2








%














;















%




"
	















!






















!


@


	



















!

@B
&
!

1
78

0

 
0
8
1!


1
(
81
(
3

7
(
8'
'
!
1
'
81
7

 
8

7!

















'

	


%
1

(8
1
0C











1
1
*8
1
1(






"

	
!

1
C
81
C
1

(
3
8
7
(!


1
C8
0
3


*
*8
(
!

1
(
81
0
(


'
3
8
(!


1
3
81
'
C

*
3
8'
C
!

E













A









A









A









;



;



A









2

	




















@


	



















!

@B
&
!

1
(
81
*

7
 
80
1!


1
(
81
3
(

7
(
8

7
!

1
17
81

'

*
(
87
!

1
'8
1
0

3
8*
!

1
08
1
*C

*
C
8
1!


1
1'
81

(

(
8'
!

1
*
81
3

(
87
!












	









2






2

	


D


%

*
C3
8
C*
*




4

	
"










	





D



%
*
3 
8
73
7




&










D






	



	


	

!
%
(
11
8
30
( 




2

	


F

.
%

( 
08
7(
1




<




,





G


!






,









!%

C0
 8
3
1




H
"

%

0*
8
I
*C
0




J




D







D








%


0
17
83
('
1





 Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  21REVISION OF RADICIPES 
FIGURE 14. Sclerites of Radicipes aureus Kükenthal, 1919 (ZMB 8565, holotype). A: rods from the body wall; B: infrabasal 
scales; C: coenenchymal scales; D: pinnular scales; E: tentacular rods. Scale bar: 0.2 mm.
Comparisons. This species is morphologically close to R. challengeri (Table 1), with similar sclerite sizes. 
However, R. kopelatos has body wall rods proportionally thicker than those in R. challengeri, with a more 
homogeneous diameter in these sclerites. The latter also has usually smaller polyps. 
Remarks. There are no new records for this species since its recent discovery in southern Brazil (Cordeiro et 
al., 2015). Besides the west coast of the African continent, the Brazilian slope is one of the most poorly known 
areas in the Atlantic. Thus, it is essential to collect new material in those areas and invest in integrative taxonomic CORDEIRO ET AL.22  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press
studies that could help to better understand the relationship between eastern and western populations of the Atlantic 
Ocean (R. kopelatos, R. challengeri and R. gracilis).
Distribution. Western Atlantic, Southeastern Brazil, 592–750 m.
Radicipes aureus Kükenthal, 1919
Figs. 2G, 14
Radicipes aureus Kükenthal, 1919: 544–545, text-figs. 237–239; 1924: 412.—Cordeiro et al., 2015: 95 (tabular key). 
?Radicipes sp. Williams, 1992: 253.
Types and Type Locality. Part of the syntype series, from Valdivia 245, is lost. Thus, the remaining part, from 
Valdivia 257 (ZMB 8565), is herein designated as the lectotype; 1°48'N, 45°42'30"E (Somalia), 1644 m. 
Material Examined. Lectotype (several fragments).
Description of the lectotype. Colony coiled with maximum axis diameter of 1.0 mm. Axis basally 
quadrangular with rounded edges in cross-section, but round in remainder of colony. Polyps around 5.0 mm long 
(Fig. 2G), 1.3 mm wide and uniserially placed, separated by an average distance of 5.0 mm, sometimes less. Polyps 
upwardly oriented at least 45°, cylindrical, having an enlargement at the base. Basal enlargement usually filled with 
gametes. Sclerites from polyp body wall longitudinally arranged (Fig. 2G). Most abundant sclerites from body wall 
represented by elongate rods, with at least one much flattened tip, 0.7–1.2 mm long and 0.07–0.13 mm in width 
(Fig. 14A). Abaxial supporting rods more elongated at the polyp base, decreasing in length towards the tentacles. 
Outer lateral and inner lateral rows composed of one to three long rods. Adaxial rows with several smaller rods. 
Infrabasal pointed scales transversely arranged in six to ten rows, 0.5–1.0 mm long, forming a bulb-like base (Fig. 
14B). Coenenchyme and base of polyp formed by elongate scales, with irregular margins and pointed tips, 
sometimes forked, 0.2–0.6 mm long and 0.04–0.1 mm wide (Fig. 14C). Tentacular rods homogeneous in diameter, 
0.15–0.4 mm long and 0.019–0.020 mm wide (Fig. 14E). Pinnular scales 0.08–0.13 mm long (Fig. 14D).
Comparisons. Radicipes aureus has large body wall sclerites, as do all Indo-Pacific species (except for R. 
spiralis), but is distinguished from all species of the genus by having long pointed body wall rods with one flat tip, 
and pointed scales in the base. Generally, this species is the only one to show polyps covered by conspicuous 
scales.
Remarks. We only had access to a single polyp from lot ZMB 8565. Therefore, characters related to the 
colony and arrangement of polyps were described based on drawings and description given by Kükenthal (1919). 
For example, according to Kükenthal, colonies can reach 56 cm in length.
This is another species with only a single record since its description. We suppose that the Radicipes sp. record 
of Williams (1992) may belong to this species, based on the proximity of the geographic distribution. Only the 
original was identified to species level. All further records are compiled or identified to genus level. There are no 
additional reports of Radicipes species in the Indian Ocean.
Distribution. Western Indian Ocean, from Somalia to South Africa, 463–1644 m.
Acknowledgments
The authors would like to thank the National Museum of Natural History (Smithsonian Institution), for the use of their 
facilities, collections and Scanning Electron Microscope, especially to collection managers Chad Walter, Bill Moser 
and Geoff Keel. Thanks to Dr. Herman Wirshing for providing DNA sequences used herein. We also thank curators 
and collection managers from other institutions who provided additional specimens examined in this study: Eric Lazo-
Wasem and Lourdes Rojas (Peabody Museum of Natural History), Adam Baldinger (Museum of Comparative 
Zoology), Carsten Lüter (Zoologisches Museum) and Andrew Cabrinovic (British Natural History Museum). Special 
thanks to Dr. Les Watling and to Dr. Phil Alderslade for sharing their opinions and knowledge of this genus with us. 
We are also grateful to Dr. Andreia Braga-Henriques, Dr. Jana Thoma and to the anonymous reviewer, for their 
contributions to the improvement of this manuscript. Thanks to NOAA for providing in situ images used herein and 
geographic data for some specimens. Finally, we thank Capes (Coordenação de Aperfeiçoamento de Pessoal de Nível 
Superior) for the research grant given to the first author (PDSE 99999.006617/2015-08).  Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  23REVISION OF RADICIPES 
References
Alderslade, P., Althaus, F., Mcennulty, F., Gowlett-Holmes, K. & Williams, A. (2014) Australia’s deepwater octocoral fauna: 
historical account and checklist, distributions and regional affinities of recent collections. Zootaxa, 3796 (3), 435–452. 
https://doi.org/10.11646/zootaxa.3796.3.2
Althaus, F., Williams, A., Schlacher, T.A., Kloser, R.J., Green, M.A., Barker, B.A., Bax, N.J., Brodie, P. & Schlacher-
Hoenlinger, M.A. (2009) Impacts of bottom trawling on deep-coral ecosystems of seamounts are long-lasting. MEPS, 397, 
279–294. 
https://doi.org/10.3354/meps08248
Altuna, A. (2010) Listado de los cnidarios bentónicos (Cnidaria) del Golfo de Vizcaya y zonas próximas (Atlántico NE) (42ºN 
a 48º30’N y 10ºW). In: Proyecto Fauna Ibérica. Museo Nacional de Ciencias Naturales, Madrid, pp. 1–27. 
Baker, K.D., Wareham, V.E., Snelgrove, P.V.R., Haedrich, R.L., Fifield, D.A., Edinger, E.N. & Gilkinson, K.D. (2012) 
Distributional patterns of deep-sea coral assemblages in three submarine canyons off Newfoundland, Canada. Marine 
Ecology Progress Series, 445, 235–249.  
https://doi.org/10.3354/meps09448
Bayer, F.M. (1949) Chalcogorgiinae, a new subfamily of Chrysogorgiidae (Coelenterata: Alcyonaria), and a description of 
Chalcogorgia pellucida, new genus and new species, from the Straits of Florida. Journal of the Washington Academy of 
Sciences, 39 (7), 237–240.
Bayer, F.M. (1956) Octocorallia. In: Moore, R.C. (Ed.), Treatise on Invertebrate Paleontology, Part F. Coelenterata. 
Geological Society of America and University of Kansas Press, Lawrence, Kansas, pp. 163–231. [F163–F231]
Bayer, F.M. (1961) The shallow-water Octocorallia of the West Indian region. A manual for marine biologists. Studies of the 
Fauna of Curacao and Other Caribbean Islands, 12, 1–373.
Bayer, F.M. (1979) Distichogorgia sconsa, a new genus and new species of chrysogorgiid octocoral (Coelenterata: Anthozoa) 
from the Blake Plateau off northern Florida. Proceedings of the Biological Society of Washington, 92 (4), 876–882.
Bayer, F.M. (1981) Key to genera of Octocorallia exclusive of Pennatulacea (Coelenterata, Anthozoa), with diagnosis of new 
taxa. Proceedings of the Biological Society of Washington, 94 (3), 902–947.
Bayer, F.M., Grasshoff, M. & Verseveldt, J. (1983) Illustrated Trilingual Glossary of Morphological and Anatomical Terms 
Applied to Octocorallia. E. J. Brill/Dr. W. Backhuys, Leiden, 75 pp.
Bayer, F.M. & Macintyre, I.G. (2001) The mineral component of the axis and holdfast of some gorgonacean octocorals 
(Coelenterata: Anthozoa), with special reference to the family Gorgoniidae Proceedings of the Biological Society of 
Washington, 114 (1), 309–345.
Bayer, F.M. & Muzik, K.M. (1976) New genera and species of the holaxonian family Chrysogorgiidae (Octocorallia: 
Gorgonacea). Zoologische Mededelingen, 50 (5), 65–90.
Bayer, F.M. & Stefani, J. (1988) A new species of Chrysogorgia (Octocorallia: Gorgonacea) from New Caledonia, with 
descriptions of some other species from the Western Pacific. Proceedings of the Biological Society of Washington, 101 (2), 
257–279.
Braga-Henriques, A., Porteiro, F.M., Ribeiro, P.A., Matos, V., Sampaio, I., Ocaña, O. & Santos, R.S. (2013) Diversity, 
distribution and spatial structure of the cold-water coral fauna of the Azores (NE Atlantic). Biogeosciences, 10, 4009–
4036.  
https://doi.org/10.5194/bg-10-4009-2013
Buhl-Mortensen, L., Buhl-Mortensen, P., Holte, B., Dannheim, J., Kröger, K., Dolan, M. & Picard, K. (2010) Dyreliv på 
havbunnen Tromsøflaket og Eggakanten. In: Buhl-Mortensen L., Hodnesdal, H. & Thorsnes, T. (Eds.), Til bunns i 
Barentshavet og havområdene utenfor Lofoten-ny kunnskap fra MAREANO for økosystembasert forvaltning, Norges 
geologiske undersøkelse, Trondheim, pp. 36–41.
Buhl-Mortensen, L., Olafsdottir, S.H., Buhl-Mortensen, P., Burgos, J.M. & Ragnarsson, S.A. (2015) Distribution of nine cold-
water coral species (Scleractinia and Gorgonacea) in the cold temperate North Atlantic: effects of bathymetry and 
hydrography. Hydrobiologia, 759, 39–61.  
https://doi.org/10.1007/s10750-014-2116-x
Cairns, S.D. (2015) New abyssal Primnoidae (Anthozoa: Octocorallia) from the Clarion-Clipperton Fracture Zone, equatorial 
northeastern Pacific. Marine Biodiversity, 46, 141–150.  
https://doi.org/10.1007/s12526-015-0340-x
Cairns, S.D. & Chapman, R.E. (2001) Biogeographic affinities of the north Atlantic deep-water Scleractinia. In: Willison, 
J.H.M. (Ed.), Proceedings of the First International Symposium on Deep-Sea Corals. Ecology Action Centre and Nova 
Scotia Museum, Halifax, Nova Scotia, pp. 30–57.
Cairns, S.D. & Cordeiro, R.T.S. (2017) A new genus and species of golden coral (Anthozoa, Octocorallia, Chrysogorgiidae) 
from the Northwest Atlantic. ZooKeys, 668, 1–10.  
https://doi.org/10.3897/zookeys.668.12203
Cairns, S.D., Gerhswin, L.A., Brook, F., Pugh, P.R., Dawson, E.W., Ocaña, V.O., Vervoort, W., Williams, G., Watson, J., 
Opresko, D.M., Schuchert, P., Hine, P.M., Gordon, D.P., Campbell, H.J., Wright, A.J., Sanchez, J. & Fautin, D.G. (2009) 
Phylum cnidaria; corals, medusae, hydroids, myxozoa. In: Gordon, D.P. (Ed.), New Zealand inventory of biodiversity. Vol 
1. Kingdom Animalia: Radiata, Lophotrochozoa, Deuterostomia. Canterbury University Press, Christchurch, pp. 59–101.
Castro, C.B., Pires, D.O., Medeiros, M.S., Loiola, L.L., Arantes, R.C.M., Thiago, C.M. & Berman, E. (2006) Filo Cnidaria. 
Corais. In: Lavrado, H.P. & Ignacio, B.L. (Eds.), Biodiversidade bentônica da região central da Zona Econômica 
Exclusiva brasileira. Série Livros No. 18. Museu Nacional, Rio de Janeiro, pp. 147–192.CORDEIRO ET AL.24  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press
Cogswell, A.T., Kenchington, E.L.R., Lirette, C.G., MacIsaac, K., Best, M.M., Beazley, L.I. & Vickers, J. (2009) The current 
state of knowledge concerning the distribution of coral in the Maritime Provinces. Canadian Technical Report of Fisheries 
and Aquatic Sciences, 2855, 1–66.
Cordeiro, R.T.S., Castro, C.B. & Pérez, C.D. (2015) Deep-water octocorals (Cnidaria: Octocorallia) from Brazil: Family 
Chrysogorgiidae Verrill, 1883. Zootaxa, 4058 (1), 081–100.  
https://doi.org/10.11646/zootaxa.4058.1.4
Deichmann, E. (1936) The Alcyonaria of the Western part of the Atlantic Ocean. Memoirs of the Museum of Comparative 
Zoology, 53, 253–308.
Duchassaing, P. & Michelotti, J. (1864) Supplément au mémoire sur les corallaires des Antilles. Memorie della Reale 
Accademia delle Scienze di Torino, 2 (23), 97–206.
Fujita, T. (2001) Submersible observations on the euryaline brittle star, Asteronyx loveni (Echinodermata, Ophiuroidea), living 
in association with a gorgonacean coral. In: Barker, M.F. (Ed.), Echinoderms 2000 - Proceedings of the 10th International 
Echinoderm Conference, Balkema (Swets & Zeitlinger), Lisse, pp. 267–272.
Fujita, T. & Ohta, S. (1988) Photographic observations of the life style of a deep-sea ophiuroid Asteronyx loveni
(Echinodermata). Deep-Sea Research, 35 (12), 2029–2043. 
https://doi.org/10.1016/0198-0149(88)90123-9
Goff-Vitry, M.C., Rogers, A.D. & Baglow, D. (2004) A deep-sea slant on the molecular phylogeny of the Scleractinia. 
Molecular Phylogenetics and Evolution, 30, 167–177.  
https://doi.org/10.1016/S1055-7903(03)00162-3
Gonzalez-Mirelis, G. & Buhl-Morthensen, P. (2015) Modelling benthic habitats and biotopes off the coast of Norway to support 
spatial management. Ecological Informatics, 30, 284–292. 
https://doi.org/10.1016/j.ecoinf.2015.06.005
Grasshoff, M. (1981) Gorgonaria und Pennatularia (Cnidaria: Anthozoa) von Mittelatlantischen Rücken SW der Azoren. 
Steenstrupia, 7 (9), 213–230.
Grasshoff, M. (1999) The shallow-water gorgonians of New Caledonia and adjacent islands (Coelenterata: Octocorallia). 
Senckenbergiana Biologica, 78, 1–245.
Grigg, R.W. & Bayer, F.M. (1976) Present knowledge of the systematic and zoogeography of the order Gorgonacea in Hawaii. 
Pacific Science, 30 (2), 167–175.
Haeckel, E. (1876) Arabische Korallen. Ein Ausflug nach den Korallenbanken des Rothen Meeres und ein Blick in des Leben 
der Korallenthiere. Georg Reimer, Berlin, 48 pp.
ICZN (1999) International Code of Zoological Nomenclature (online). The International Trust for Zoological Nomenclature, 
The Natural History Museum, Cromwell Road, London. Available from: http://www.iczn.org/code (accessed 4 August 
2017)
Jungersen, H.F.E. (1915) Alcyonaria, Antipatharia og Madreporaria. Conspectus Faunae Groenlandicae. Meddelelser 
Gronland, 23, 1156–1212.
Kinoshita, K. (1913) Studien uber einige Chrysogorgiiden Japans. Journal of the College of Science, University of Tokyo, 33 
(2), 1–47.
Kramp, P.L. (1932) The Godthaab Expedition 1928. Alcyonaria, Antipatharia, and Madreporaria. Meddelelser Gronland, 79 
(4), 1–20.
Kükenthal, W. (1919) Gorgonaria. Wissenschaftliche Ergebnisse der Tiefsee-Expedition Valdivia, 13 (2), 1–946. 
Kükenthal, W. (1924) Gorgonaria. Das Tierreich, 47, 1–478.
Kumar, S., Stecher, G. & Tamura, K. ( 2016) MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger 
datasets. Molecular Biology and Evolution, 33, 1870–1874. 
https://doi.org/10.1093/molbev/msw054
Lamouroux, J.V.F. (1812) Extrait d'un mémoire sur la classification des polypiers coralligènes non entièrement piérreux. 
Nouveau Bulletin des Sciences, Société Philomathique de Paris, 3 (63), 18l–188.
Madsen, F.J. (1944) Octocorallia. Danish Ingolf-Expedition, 5 (13), 1–65.
Matsumoto, A., Iwase, F., Imahara, Y. & Namikawa, H. (2007) Bathymetric distribution and biodiversity of cold-water 
octocorals (Coelenterata: Octocorallia) in Sagami Bay and adjacent waters of Japan. In: George, R.Y. & Cairns, S.D. 
(Eds.), Conservation and adaptive management of seamount and deep-sea coral ecosystems. Rosenstiel School of Marine 
and Atmospheric Science, University of Miami, Coral Gables, Florida, pp. 231–251.
McFadden, C.S., Benayahu, Y., Pante, E., Thoma, J.N., Nevarez, A. & France, S.C. (2011) Limitations of mitochondrial gene 
barcoding in Octocorallia. Molecular Ecology Resources, 11, 19–31. 
https://doi.org/10.1111/j.1755-0998.2010.02875.x
McFadden, C., France, S.C., Sanchez, J.A. & Alderslade, P. (2006) A molecular phylogenetic analysis of the Octocorallia 
(Cnidaria: Anthozoa) based on mitochondrial protein-coding sequences. Molecular Phylogenetics and Evolution, 41, 513–
527. 
https://doi.org/10.1016/j.ympev.2006.06.010
Mortensen, P.B., Buhl-Mortensen, L., Gebruk, A.V. & Krylova, E.M. (2008) Occurrence of deep-water corals on the Mid-
Atlantic Ridge based on MAR-ECO data. Deep-Sea Research II, 55, 142–152.  
https://doi.org/10.1016/j.dsr2.2007.09.018
Nutting, C.C. (1908) Descriptions of the Alcyonaria collected by the U.S. Bureau of Fisheries steamer Albatross in the vicinity 
of the Hawaiian Islands in 1902. Proceedings of the United States National Museum, 34, 543–601.  
https://doi.org/10.5479/si.00963801.34-1624.543  Zootaxa 4319 (1)  © 2017 Magnolia Press  ·  25REVISION OF RADICIPES 
Nutting, C.C. (1912) Descriptions of the Alcyonaria collected by the U.S. Fisheries steamer "Albatross," mainly in Japanese 
waters, during 1906. Proceedings of the United States National Museum, 43, 1–104. 
https://doi.org/10.5479/si.00963801.43-1923.1
Pante, E. & France, S.C. (2010) Pseudochrysogorgia bellona n. gen., n. sp.: a new genus and species of chrysogorgiid octocoral 
(Coelenterata, Anthozoa) from the Coral Sea. Zoosystema, 32 (4), 595–612.  
https://doi.org/10.5252/z2010n4a4
Pante, E., France, S., Couloux, A., Cruaud, C., McFadden, C.S., Samadi, S. & Watling, L. (2012) Deep-sea origin and in-situ 
diversification of chrysogorgiid octocorals. PLoS ONE, 7 (6), e38357.  
https://doi.org/10.1371/journal.pone.0038357
Parrish, F.A. & Baco, A.R. (2007) Chapter 4. ‘State of Deep Coral Ecosystems in the United States Western Pacific Region: 
Hawaii and the United States Pacific Islands.’ In: Lumsden, S.E. & Hourigan, T.F., Bruckner, A.W. & Dorr, G. (Eds.), The 
State of Deep Coral Ecosystems of the United States. NOAA Technical Memorandum CRCP-3. Silver Spring, MD, pp. 
155–194.
Pires, D.O. & Castro, C.B. (2010) Cnidaria. In: Lavrado, H.P. & Brasil, A.C.S. (Eds.), Biodiversidade da região ocânica 
profunda da Bacia de Campos: Megafauna e Ictiofauna Demersal. SAG Serv, Rio de Janeiro, pp. 59–112.
QGIS Development Team (2015) QGIS Geographic Information System. Open Source Geospatial Foundation. Available from: 
http://qgis.osgeo.org (accessed 13 March 2017)
Rueda, J.L., Urra, J., Gofas, S., López-González, N., Fernández-Salas, L.M. & Díaz-del-Río, V. (2012) New records of recently 
described chemosymbiotic bivalves for mud volcanoes within the European waters (Gulf of Cádiz). Mediterranean 
Marine Science, 13 (2), 262–267. 
https://doi.org/10.12681/mms.307
Stearns, R.E.C. (1883) Descriptions of a new genus and species of alcyonoid polyp, from Japanese waters, with remarks on the 
structure and habits of related forms, etc. Proceedings of the United States National Museum, 6, 96–101. 
https://doi.org/10.5479/si.00963801.6-346.96
Stone, R.P. (2005) Exploring deep-sea coral habitat on the edge–Alaska’s Aleutian Islands. The Journal of Marine Education, 
21 (4), 18–21.
Stone, R.P. & Shotwell, S.K. (2007) State of Deep Coral Ecosystems in the Alaska Region: Gulf of Alaska, Bering Sea and the 
Aleutian Islands. In: Lumsden, S.E. & Hourigan, T.F., Bruckner, A.W. & Dorr, G. (Eds.), The State of Deep Coral 
Ecosystems of the United States. NOAA Technical Memorandum CRCP-3. Silver Spring, MD, pp. 65–108.
Studer, T. (1887) Vesuch eines Systemes der Alcyonaria. Archiv für Naturgeschichte, 53 (1), 1–74.
Thomson, J.A. (1927) Alcyonaires provenant des campagnes scientifiques du Prince Albert Ier de Monaco. Résultats des 
Campagnes Scientifiques Albert I, 73, 1–77.
Thomson, J.A. & Henderson, W.D. (1906) An account of the Alcyonarians collected by the Royal Indian Survey Ship 
Investigator in the Indian Ocean. Part 1. The Alcyonarians of the Deep Sea. Indian Museum, Calcutta, 132 pp.
Tixier-Durivault, A. & d’Hondt, M.J. (1975) Les Octocoralliaires de la champagne Biaçores. Bulletin du Muséum National 
d’Histoire Naturelle, 174 (252), 1361–1433.
Verrill, A.E. (1883) Report on the Anthozoa, and on some additional species dredged by the "Blake" in 1877–1879, and by the 
U.S. Fish Commission steamer "Fish Hawk" in 1880–82. Bulletin of the Museum of Comparative Zoology, 11, 1–72.
Verrill, A.E. (1884) Notice of the remarkable marine fauna occupying the outer banks off the southern coast of New England, 
No. 9. Brief contributions to zoology from the Museum of Yale College. No. 55. American Journal of Science, 28 (3), 
213–220. 
https://doi.org/10.2475/ajs.s3-28.165.213
Verrill, A.E. (1885) Results from the explorations made by the steamer Albatross off the northern coast of the United States in 
1883. Annual Report of the Commissioner of Fish and Fisheries for 1883, 1885, 503–699.
Verrill, A.E. (1922) Alcyonaria and Actinaria. Report of the Canadian Arctic Expedition, 8 (G), 1–164.
Versluys, J. (1902) Die Gorgoniden der Siboga-Expedition. I. Die Chrysogorgiiden. Siboga Expeditie, 13, 1–120.
Versluys, J. (1906) Die Gorgoniden der Siboga Expedition. II. Die Primnoidae. Siboga-Expeditie, 13a, 1–187.
Wareham, V.E. & Edinger, E.N. (2007) Distribution of deep-sea corals in the Newfoundland and Labrador region, Northwest 
Atlantic Ocean. In: George, R.Y. & Cairns, S.D. (Eds.), Conservation and adaptive management of seamount and deep-sea 
coral ecosystems. Rosenstiel School of Marine and Atmospheric Science, University of Miami, pp. 289–313.
Watling, L. (2007) A review of the genus Iridogorgia (Octocorallia: Chrysogorgiidae) and its relatives, chiefly from the North 
Atlantic Ocean. Journal of the Marine Biological Association of the United Kingdom, 87, 393–402.  
https://doi.org/10.1017/S002531540705535X 
Watling, L. & Auster, P. (2005) Distribution of deep-water Alcyonacea off the northeast coast of the United States. In: 
Freiwald, A. & Murray, R.J. (Eds.), Cold-Water Corals and Ecosystems. Springer-Verlag, Berlin, Heidelberg, pp. 279–296. 
https://doi.org/10.1007/3-540-27673-4_13
Watling, L., France, S., Pante, E. & Simpson, A. (2011) Biology of deep-water octocorals. In: Lesser, M. (Ed.), Advances in 
Marine Biology. Elsevier Academic press, London, pp. 41–122. 
https://doi.org/10.1016/B978-0-12-385529-9.00002-0
Williams, G.C. (1992) The Alcyonacea of southern Africa. Gorgonian octocorals (Coelenterata, Anthozoa). Annals of the South 
African Museum, 101 (8), 181–296.
Wright, E.P. (1885) The Alcyonaria. In: Report on the Scientific Results of H. M. S. Challenger. Narrative, 1 (2), 689–693.
Wright, E.P. & Studer, T. (1889) Report on the Alcyonaria collected by H.M.S. Challenger during the years 1873–1876. Report 
on the Scientific Results of H. M. S. Challenger during the years 1873–76, Zoology, 31 (64), 1–314.CORDEIRO ET AL.26  ·  Zootaxa 4319 (1)  © 2017 Magnolia Press