Protankyra ramiurna Heding 1928

Christoffersen, Martin Lindsey, 2017, Taxonomic status of Protankyra ramiurna and Protankyra benedeni (Holothuroidea: Apodida: Synaptidae), Zootaxa 4324 (3), pp. 518-528 : 519-522

Protankyra ramiurna Heding 1928

Figures 1–2 , Table 1

Protankyra ramiurna HEDING 1928 : 275 –276, FIG. 54; HENDLER et al. 1995: 310, FIG. 190A–c.

Material examined. Port of Cabedelo, Municipality of Cabedelo, Paraiba, Brazil, (06°56'87"S; 34°50'10"W), 1 spec. ( UFPB.ECH-2125); Fortaleza Reef, in front of Ferreira (Tarra), Prado, Bahia, Brazil, 2 spec. (EQMN-1669).

Diagnosis. Small, vermiform, reaching about 15 cm long. Body wall thin and translucent. Mouth surrounded by 12 digitate tentacles, each with two pair of digits. Dichotomic ciliated funnels with ramifications contorted. Ossicles of the body wall comprise anchors (200–300 µm), anchor plates with large central and smaller marginal perforations (200–260 µm), and diamond-shaped to rounded miliary granules (30 µm) in the radial muscles. Posterior region with ossicles larger than those from anterior region ( Heding 1928, amended herein).

Type locality. West Indies ( Heding 1928).

Type material. Holotype in the Zoological Museum, Natural History Museum of Denmark, Denmark, registered as ZMUC-HOL-216.

Description. Specimen UFPB.ECH-2125 28 mm long and 3 mm wide. Body cylindrical, skin thin, rough to the touch, and translucent ( Fig. 1A–B ). Muscle bands and some internal organs clearly visible along length of body. Twelve robust and digitate tentacles. Each tentacle with two simple and pointed digits, as well as a shorter and terminal digit; two lateral tentacles, on opposite sides, longer than the others ( Figs. 1C–D ). Color white to translucent yellow, with some irregular purple spots. Calcareous ring simple with five radial and five interradial plates, all fused to form narrow ring; radial plates slightly narrower than interradial plates, rectangular-shaped, with a slight central hole in posterior region ( Fig. 1E ). Interradial plates trapezoid in shape. Ten cylindrical polian vesicles, an elongated, twisted stone canal, and a cordiform madreporite. Ciliated funnels with tubules bifurcated in two or more branches, which have a spiral aspect ( Fig. 1F ). Longitudinal muscles thin, undivided. Gonads not developed. Body wall with anchor plates of smooth margins, a rounded and smooth base, with large dentate perforations, and about sixty holes, but these perforations are smaller in the margins ( Fig. 2A ). Smaller and numerous holes occur in the base of these plates, and there is a well-developed articulation with the anchor ( Fig. 2C ). Anchor plates from anterior region measure about 180–250 µm long and 140–180 µm wide, and those from posterior region are about 230–290 µm long and 160–200 µm wide ( Figs. 2F–G ). Anchors with smooth vertex ( Fig. 2B ), serrate arms with four to seven pairs of prominent teeth ( Fig. 2D ), and a slightly curved central axis near the stock, which is provided with minute spines ( Figs. 2E, 2H ). Anchors from anterior region about 200–250 µm long and 120–140 µm wide, whereas those from posterior region about 290–390 µm long and 140–210 µm wide ( Figs. 2F–G ). Anchors and anchor plates from anterior region are significantly smaller than those from posterior region ( Tab. 1). Diamond-shaped to rounded small miliary granules, up to 30 µm long ( Fig. 2J ). Irregularly curved rods in tentacles ( Fig. 2I ).

Distribution. Southwest coast of Puerto Rico, near La Parguera, and Biscayne Bay, Miami (Hendler et al. 1995). New record in Brazil, for the States of Paraiba and Bahia. Bathymetric distribution less than 1 m in areas mentioned in Hendler et al. (1995). Specimen UFPB.ECH-2125 was found at a depth of 8.4 m.

Ecological notes. The species was found in coral reef in rodoliths. According to Hendler et al. (1995), specimens from Puerto Rico inhabited sediments of sand and shells, coarse sand, as well as sediments adjacent to algae, and occur in Thalassia beds in Miami.

Remarks. This is the first record of P. ramiurna from the Brazilian coast. According to Heding (1928) the name of the species refers to the presence of ciliary funnels in the inner surface of the body wall, which are taxonomically important. These structures interact with the production of mucus in the coelom to remove impurities from the coelomic fluid ( Jans & Jangoux 1989).

ANcHOR PLAtES

LENGtH (µM) WIDtH (µM)

ANtERIOR MIDDLE POStERIOR ANtERIOR MIDDLE POStERIOR MEAN 209.4 274.4 263.62 161.7 198.45 182.7 S.D. 15.87 19.6 16.36 11.49 7.35 8.77 RANGE 190–235 240–289 254–294 150–181 166–201 190–205 N 30 30 30 30 30 30 ANcHORS

LENGtH (µM) WIDtH (µM)

ANtERIOR MIDDLE POStERIOR ANtERIOR MIDDLE POStERIOR MEAN 222.13 267.05 334.84 130. 67 161.7 169.66 S.D. 46.19 12.25 31.07 4.63 9.8 23.17 RANGE 161–308 294–392 254–279 127–137 147–215 151–171 N 30 30 30 30 30 30 MILIARY GRANULES

LENGtH (µM) WIDtH (µM)

ANtERIOR MIDDLE POStERIOR ANtERIOR MIDDLE POStERIOR MEAN 22.05 31.03 32.1 12.5 16.33 16.45 S.D. 2.45 2.45 12.86 2.45 2.45 6.11 RANGE 19.6–24.5 19.6–49 16.9–49 9.8–14.7 9.8–24.5 4.9– 19.6 N 30 30 30 30 30 30

SD, standard deviation; N, number of ossicles measured.

Figures

FIGURE 1. Protankyra ramiurna (HEDING). A, EXtERNAL VIEW OF tHE ANIMAL; B, ANtERIOR REGION; C – D, TENtAcLES; E, CALcAREOUS RING; F, CILIAtED FUNNELS. ScALE bARS: A – B, 1 cM; C, 2 MM; D, 1 MM; E – F, 0.5 MM.

FIGURE 2. Protankyra ramiurna (HEDING). A, ANcHOR PLAtE; B, ANcHORS; C, DEtAIL OF tHE well-developed articulation in ANcHOR PLAtE; D, ARM OF ANcHOR; E, DEtAIL OF tHE StOcK; F, ANcHOR PLAtE AND ANcHOR FROM POStERIOR REGION; G, ANcHOR PLAtE AND ANcHOR FROM ANtERIOR REGION; H, DEtAIL OF tHE KEEL OF ANcHOR; I, RODS FROM tENtAcLES; J, MILIARY GRANULES. ScALE bARS: A, 80 µM; B, F – G, 100 µM; C, E, H, 50 µM; D, 40 µM; I – J, 10 µM.