Labidodemas rugosum ( Ludwig, 1875 )

Setyastuti, Ana, Solis-Marin, Francisco Alonso & Lüter, Carsten, 2024, Sea cucumbers of the genus Labidodemas (Holothuroidea: Holothuriida: Holothuriidae) from Indonesia, with the description of a new species and a revised key to the genus, Zootaxa 5506 (2), pp. 227-244 : 229-232

publication ID	https://doi.org/ 10.11646/zootaxa.5506.2.4
publication LSID	lsid:zoobank.org:pub:55527A8F-3454-49A2-AD65-ECBAE234C03D
DOI	https://doi.org/10.5281/zenodo.13746664
persistent identifier	https://treatment.plazi.org/id/03C0F828-FFB5-3A1F-95F4-FE80FD6C3192
treatment provided by	Plazi
scientific name	Labidodemas rugosum ( Ludwig, 1875 )
status

Treatment

Labidodemas rugosum ( Ludwig, 1875) View in CoL

( Figures 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Holothuria rugosa Ludwig, 1875: 110 View in CoL , pl. 7, figs. 33a–c; Pearson, 1913: 82.

Holothuria triremis View in CoL ; Sluiter, 1901: 19, Taf. VI, Fig. 3 View FIGURE 3 .

Holothuria (Holothuria) rugosa ; Panning, 1934 (teil. 3): 75.

Labidodemas rugosa View in CoL ; Jangoux et al., 1989: 163.

Labidodemas rugosum View in CoL ; Massin et al., 2004: 1830, figs. 8A–L, map 5 (records before 2004); Purwati & Wirawati, 2011: 7, figs. 6a–b.

Type material. Holotype ZMH E.2625.

Type locality. Samoa ( Ludwig, 1875).

Material examined. Three specimens. MZB Hol. 390 (110x 55 mm in ethanol), MZB Hol. 427 (70x 15 mm in ethanol); both collected in Bilik Sajile, Baluran National Park , East Java, by snorkeling, under a rock, 3–4 m depth, coll. by Tim Teripang P 2O LIPI 2018 , 1 July 2018. MZB Hol. 425 (110x 40 mm in ethanol), coll. Bakaheuni, Lampung, South Sumatera; during low tide, under a rock, 0.5–1.5 m depth, coll. by Tim Teripang P 2O LIPI 2016 , April 2016 .

External description. Body cylindrical; specimen colour in ethanol white uniformly ( Figs. 2A, B View FIGURE 2 ). Body rather gritty, 2–3 mm thick. Mouth and anus terminal; mouth white in colour, surrounded by 18–20 yellow tentacles. Dorsal papillae small, scattered over the surface. Ventral tube feet longer than dorsal papillae (1.5–2.5 mm), white to yellowish, 3–6 rows in ambulacral areas.

Internal description. Calcareous ring with radial pieces twice higher than interradial ones (radial pieces 2–3 mm wide and 1.5–3 mm high) ( Fig. 2C View FIGURE 2 ). Cuvierian tubules present only in Hol.390, adhesive, long and thin, whitish, branched, distal part of the tube smooth, more than 10 attachment sites. Tentacle ampullae present, 2–6 mm (1/35 to 1/27 body length). Single Polian vesicle, sac-like. Stone canal straight, present in Hol.425 (4 mm) and Hol.427 (2 mm). Gonad only observed in Hol.425, one tuft, whitish, branched. Respiratory tree arises from single stalk. Longitudinal muscle flat, medially attached and lateral margins free. Inner body wall whitish with numerous black dots under the muscles. Intestine filled with small gravel and rough coral sand.

Ossicles. Dorsal body wall with tables and buttons; table discs 70–110 µm across, disc rims very spinous; margin of the disc slightly turned upward; perforated by four central holes; spire moderate to high, with four undulating pillars united by one cross beam, terminating in narrow crown consisting of a cluster of stout spines ( Fig. 3A View FIGURE 3 ). Buttons, 30–40 µm long, with three to four pairs of irregular holes, margin smooth but undulating ( Fig. 3B View FIGURE 3 ). Ventral body wall with tables and buttons; their shape similar to those of the dorsal body wall but bigger, and buttons more numerous than in dorsal body wall. Table discs 90–120 µm, and buttons 50–70 µm long ( Figs. 3C, D View FIGURE 3 ).

Dorsal papillae with tables, buttons and rods; tables similar in shape to those of dorsal body wall, but generally bigger, table disc 80–130 µm across ( Fig. 4D View FIGURE 4 ). Buttons in several shapes; rods-like buttons, 80–110 µm long ( Fig. 4A View FIGURE 4 ); buttons with four to five pairs of irregular holes, smooth rim but undulating, 50–80 µm long; buttons with rim rather spinous but blunt spines, only a few, 60–70 µm long ( Fig. 4C View FIGURE 4 ). Rods scarce, with several blunt spines and the extremities with or without perforation, 80–110 µm long ( Fig. 4B View FIGURE 4 ). Ventral tube feet with tables, buttons, and perforated plates and endplates. Tables and buttons shape similar to those in the ventral body wall, table discs 60–90 µm across and button 60–90 µm long ( Figs. 4E, F View FIGURE 4 ). Perforated plates many, 60–100 µm across, undulating or spinous edges ( Fig. 4G View FIGURE 4 ). Endplates, 240–300 µm across ( Fig. 4H View FIGURE 4 ). Tentacles with rods, mostly with smooth surfaces, straight or curved shapes, rarely with coarser surfaces ( Fig. 3E View FIGURE 3 )

Remarks. The body colour of the current materials is uniformly white, as described by Massin et al. (2004), Massin (1999), and Pearson (1913); not translucent pink, as described by James (1981). Specimens from this study found 18–20 tentacles, contrary to the previously observed 20 ( Massin et al., 2004; Massin, 1999; Rowe, 1969; Cherbonnier, 1988; Ludwig, 1875). Cuvierian tubules are absent according to Massin et al. (2004), but present in the specimen MZB Hol.390.

The current material ossicles differ from previous author descriptions in some ways. Tentacle rods are short (40–75 µm); many large table discs up to 100 µm, with four central holes and one ring of 8–12 peripheral holes, but occasionally with two rings of peripheral holes up to 14 holes in total, with the outer ring’s holes being smaller than the inner. The rim of the table disc is spinous, and the spines are longer and much more pointed than in Massin et al. (2004), Massin (1999), and James (1981), but it is similar to Pearson (1913). Table crowns never have central perforation, whereas Massin et al. (2004) usually have a small central perforation. MZB Hol.427 lacks body wall buttons but is present in MZB Hol.390 and MZB Hol.425 with undulating margins. Rods in dorsal papillae of present materials have never been documented before.

Ecology. Found in shallow waters, always less than 20 m deep ( Lane et al. 2000), but specimens from Ambon, Maluku were found at 30 m depth ( Jangoux et al. 1989), detritus/deposit feeder, under coral rocks. Intestine all specimens of this study filled with coarse sand and small gravel.

Depth range. 1–30 m.

Geographic distribution. The following new localities are added here since Massin et al. (2004: 1831, map 5) publication: West Lombok Island, Indonesia ( Purwati & Wirawati 2011), Baluran National Park-East Java and Lampung-South Sumatera, Indonesia (present study).