Radicipes kopelatos, Cordeiro, Ralf T. S., Castro, Clovis B. & Pérez, Carlos D., 2015

Cordeiro, Ralf T. S., Castro, Clovis B. & Pérez, Carlos D., 2015, Deep-water octocorals (Cnidaria: Octocorallia) from Brazil: Family Chrysogorgiidae Verrill, 1883, Zootaxa 4058 (1), pp. 81-100 : 94-96

Radicipes kopelatos sp. nov.

( Fig. 2 H, 8, 9)

Radicipes sp.1: Castro et al., 2006: 170 (listed only). Radicipes sp. 2: Castro et al., 2006: 170 (listed only).

Holotype: MNRJ 8566, 21°48’49”S, 40°01’53”W, 592.4–618.8 m

Paratypes: MNRJ 5968, 13°22’17”S, 38°36’56”W, 750 m (3 colonies); MNRJ 4361, same collection data of the holotype (55 colonies).

Diagnosis: Radicipes with malleable colonies clockwise or counterclockwise spiraled in an upward trend. Axis with iridescent aspect and calcareous rhizoidal holdfast. Slender coenenchyme, easily detachable from axis. Uniserial line of polyps with basal portion appressed to axis and an obliquous distal portion oriented upward. Polyps to 3.5 mm long. Polypar distances 1.0–4.00 mm. Body wall and coenenchyme of polypar line with rods, sometimes flattened, usually with flattened ends, longitudinally arranged. Coenenchymal flattened scales with median waist equally abundant. Sclerites in abpolypar face rare or absent, except on polyp bases.

Description of the holotype: Colony whip-like, malleable, unbranched, white, with counterclockwise spiraled upward trend, approximately 28 cm long ( Fig. 2 H). Axis with iridescent aspect, 0.7–1.0 mm diameter, rhizoidal holdfast with 5 main projections, each to 5.7 mm long. Slender coenenchyme, easily detachable from axis. Polyps with basal portion appressed to axis and oblique distal portion 0.8–3.3 mm long, upward oriented ( Fig. 8 B), arranged in single longitudinal row along entire colony (uniserial), delimiting one polypar and another abpolypar face, the former usually facing inner part of colony spiral. Inter-polypar distances 1.50–3.40 mm. Density of polyps 2–4 per centimeter. Body wall ( Fig. 8 A) and coenenchyme of polypar line ( Fig. 8 C) with finely tuberculated rods, sometimes flattened, usually with flattened ends, longitudinally arranged and sometimes sparse, 0.16–0.60 mm long. Coenenchymal flattened scales with median waist equally abundant, 0.15–0.25 mm long ( Fig. 8 E). Sclerites in abpolypar face rare or absent except on polyp bases. Adaxial and basal portion of polyps frequently filled with waisted scales similar to those of coenenchyme, slightly smaller than the spindles, 0.10–0.18 mm long ( Fig. 8 D). Scales of tentacles striated and ornamented with sparse, small tubercles, 0.08–0.12 mm long ( Fig. 8 B).

Variability of paratypes: Colonies white or yellowish, also clockwise spiraled in an upward trend ( Fig. 9 A), to 58 cm long, with smooth, white, root-like and calcareous holdfast, typical for attaching on soft bottoms ( Fig. 9 C). Polyps 0.8–3.5 mm long. Polypar distances 1.0–4.00 mm. Density of polyps usually decreasing in base-apex direction, with up to 5 polyps per centimeter on the proximal 2/3 of the colony and 4–3 polyps per centimeter on the distal third.

Remarks: Radicipes is a monophyletic genus (Pante et al., 2012), but it probably is the one with the poorest descriptions in terms of morphological characteristics within Chrysogorgiidae and a review of its species is imperative. As in other groups within the Chrysogorgiidae , the sclerite forms in Radicipes have little variation (usually rods and scales). The main distinction between species is the distribution of these sclerites throughout the colony and polyp.

There are no recent reviews on the genus Radicipes in the Atlantic. The two last works that present some discussion of the genus were given by Deichmann (1936) and Madsen (1944). The former includes the analysis of only one specimen, identified by the author as R. gracilis . Deichmann (1936), however, provides only information already given in the species description by Verrill (1922), not mentioning well-established characteristics in previous taxonomic keys and leaving aside even length measurements of polyps; an important taxonomic character of the group—see Kükenthal (1919, 1924). The study published by Madsen (1944) has the most complete descriptions and illustrations about the genus, but unfortunately includes only Atlantic species. Several important features raised by Madsen (1944) distinguish Radicipes kopelatos sp. nov. from other Atlantic species. Radicipes challengeri has practically no sclerites between the zooids, with spaces of up to 2 mm between coenenchymal sclerites. In Radicipes gracilis, Madsen (1944) describes that the coenenchyme is almost all filled with 8-shaped challengeri and R. gracilis .?Unknown data

scales, whereas R. kopelatos sp. nov. has rods equally abundant. Diagnostic features for all other valid species of the genus are compared to Radicipes kopelatos sp. nov. in Table 2 .

This is the first description of a species of Radicipes from the South Atlantic.

Etymology: Greek kope, f. oar; kopelatos , like an oar (see Brown, 1956: 566); referring to the flattened ends of its coenenchymal rods. Gender male.

Distribution: Known only from the type locality, Southeastern Brazil, 592–750 m depth.

Figures

FIGURE 2. Deep-water Chrysogorgiidae from Brazil. A: holotype of Chrysogorgia upsilonia sp. nov. (MNRJ 6016); B: holotype of Chrysogorgia tuberculata sp. nov. (MNRJ 8565); C: Chrysogorgia multiflora Deichmann, 1936 (MOUFPE-CNI 147); D: Paratype of Chrysogorgia upsilonia (MNRJ 6016); E: juvenile colony of Chrysogorgia fewkesi Verrill, 1883 (MNRJ 6703); F: adult colony of C. fewkesi (MOUFPE-CNI 148); G: Chrysogorgia elegans (MNRJ 6785); H: holotype of Radicipes kopelatos sp. nov. (MNRJ 8566). Scale bars: 10 mm.

FIGURE 8. Sclerites of Radicipes kopelatos sp. nov. (MNRJ 8566, holotype). A, C: rods from polyp body wall and coenenchyme, respectively; B: tentacular scales; D: scales from polyp adaxial side; E, F: coenenchymal flattened scales with median waist. Scale bars: A – E: 0.19 mm; F: 0.70 mm.

FIGURE 9. General features in paratypes of Radicipes kopelatos sp. nov. (MNRJ 4361). A: a clockwise spiraled colony; B: detail of a polyp; C: root like calcareous holdfast. Scale bar: 10 mm.

Tables

TABLE 2. Comparison of morphological and distributional characters of valid species of Radicipes, according to their original descriptions and Madsen (1944) for R.

Characters/ Species	R. kopelatos sp. nov.	R. pleurocristatus Stearns, 1883	R. verrilli (Wright, 1885)	R. aureus Kükenthal, 1919	R. challengeri (Wright, 1885)	R. gracilis (Verrill, 1884)	R. spiralis (Nutting, 1908)	R. fragilis (Wright & Studer, 1889)
Polypar length	0.8–3.3 mm	7.0 mm	3.5 mm	5.0 mm	2.5–8.0 mm	5.0–10 mm	1.5 mm	4.0–4.5 mm
Shape of the coenenchymal sclerites	Rods with flattened ends and scales with median waist	Oblong with irregular margin	Flat, wrinkled with pointed or rounded ends	Plate (scales?)	Biscuit (8-shaped), scale-like	Oblong, scale-like, median waist	-	Rare or absent
Length of polypar sclerites	0.16–0.60 mm	4.0 mm	2.0 mm	1.3 mm	0.17–0.4 mm	0.3–0.5 mm	-	0.76 mm
Length of tentacular sclerites	0.8–0.12 mm	0.9 mm	?	0.1 mm	0.12–0.25 mm	0.1–0.2 mm	-	?
Length of coenenchymal sclerites Interpolypar distances	0.16–0.60 mm 1.5–3.6 mm	0.8 mm	0.5 mm 2.0–5.0 mm	0.36 mm 5.0 mm	0.12–0.25mm 4.0–5.0 mm	0.13–0.30 mm 5.0–10.0 mm	- 3.5 mm	? 1.0–5.0 mm
Others distinctive	Colony with one polypar	Naked lateral wall	Translucent axis	Spiral axis, squared near the base, polyps not	Few coenenchymal	Rigid stem, scales with	Sclerites absent	Flattened spindles in the
characters Distribution	face with sclerites and naked abpolypar face Brazil, 592– 750 m	Japan and the Malay Archipelago, abyssal	Japan and the Malay Archipelago, Andaman, abyssal,1034 m.	appressed (45°), basal sclerites transversely arranged Indian Ocean (West Equatorial Africa), 1644 m	sclerites, scales as polypar sclerites Spain (Cadiz), 1080 m; Davis Strait, 2626 m; Off Iceland, 1717 m.	median waist as polypar sclerites North Atlantic (Coast of North America between 38°50’N and 62°57’N), 957–3120 m	Hawai, 242–258 m	body wall West of Açores (38°25’N, 35°50’W), 3015 m