Radicipes pleurocristatus Stearns 1883
Creators: name: Perez, Carlos D.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Cnidaria
Anthozoa
Alcyonacea
Chrysogorgiidae
Radicipes
Radicipes pleurocristatus

description: Radicipes pleurocristatus Stearns, 1883
Figs. 1 B,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).
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. 2 H–I’). Wider saddle bags and oral portions in fertile polyps (Fig. 2 I’). 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. 4 A, 5A). Rods cylindrical to slightly flattened or with flattened tips (rare) (Fig. 4 B). 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. 2 I’); infertile or not completely developed polyps lack saddle bag and transversely arranged sclerites (Fig. 2 H). 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. 4 C, 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. 4 E, 5B). Flattened pinnular rods 0.09–0.26 mm long and 0.01–0.05 mm wide (Figs. 4 D, 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. 2 H,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. 2 I,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.
description: Published as part of Perez, Carlos D., 2017, A revision of the genus Radicipes Stearns, 1883 (Anthozoa: Octocorallia: Chrysogorgiidae), pp. 1-26 in Zootaxa 4319 (1) on pages 6-9, DOI: 10.11646/zootaxa.4319.1.1, http://zenodo.org/record/893037