Stichopus vastus Sluiter, 1887

Woo, Sau Pinn, Yasin, Zulfigar, Tan, Shau Hwai, Kajihara, Hiroshi & Fujita, Toshihiko, 2015, Sea cucumbers of the genus Stichopus Brandt, 1835 (Holothuroidea, Stichopodidae) in Straits of Malacca with description of a new species, ZooKeys 545, pp. 1-26 : 6-9

Taxon classification Animalia Aspidochirotida Stichopodidae

Stichopus vastus Sluiter, 1887 Figs 8, 9

Stichopus vastus Sluiter, 1887: 198, pl. 2, figs 46-48; Rowe and Gates 1995: 326; Massin 1999: 71, figs 57 a–l, 58 a–m, 29 a–g, 60 a–d, 61, 112d,e; James 1998: 13, fig. 1; Massin et al. 2002: 92, pl. 2E, F, figs 12, 13.

Stichopus spec; Colin and Arneson 1995: 262, fig. 1242; Gosliner et al. 1996: 282, fig. 1039.

Stichopus " variegatus " ; Colin and Arneson 1995: 262, fig. 1240.

Material examined.

One specimen, USM/MSL/PLAN001.

Type locality.

Java, Indonesia.

Description.

External morphology: Body slightly quadrangular in cross-section, without distinct edges. Body surface smooth and tough. Black deep depression lines on dorsal body; dorsal background brown colour with numerous darker brown strips transverse and encircles the base of papillae. Two rows of large papillae with very low protrusion on dorsal body. Tube feet only in ambulacral areas; median tube feet twice wider than those in other two ambulacral areas; narrow interambulacral areas clearly separates each ambulacrum area. Reddish brown background colour on ventral side with lighter yellowish-brown on interambulacral areas. Ventral mouth with 18-20 peltate tentacles surrounded by ring of minute papillae at oral opening (Fig. 8).

Spicule: Tables, C-shaped rod, and rosette spicules present in dorsal body (Fig. 9 A–D). Tables in dorsal body with large quadrangular base, four central perforations, and 15-27 smaller peripheral holes; four pillars forming spire from the central of the base with a cross beam connecting them; tip of pillars with multiple thorny spines (Fig. 9A). Reduced tables in dorsal body having similar structure to the base of tables but lack pillars; slightly raised surface on the central (Fig. 9D). Spicule of papillae consists of tables, reduced tables, C-shaped rods, rosettes, and perforated plates (Fig. 9 I–M). Tables in papillae similar to those in dorsal body; some with larger thorns on pillar apexes (Fig. 9I). Some C-shaped rods were modified liken S-shaped rods with protrusion at the middle body (Fig. 9K). In ventral tube feet, centrally-perforated rods, perforated plates, tables, and C-shaped rods (Fig. 9 E–H) present. Centrally-perforated rods in tube feet have conspicuous large central plate and multiple perforations of different sizes; surface rough and covered with spinelets (Fig. E). Oval- to square-shaped perforated plates; rim were not smooth and jagged (Fig. 9F). Tables in tube feet have small base disc with four main central holes and 5-8 peripheral holes; four pillars erected from central of base with thorny crowns on the tip, but do not extend out of base (Fig. 9G). Small C-shaped rods in tube feet (Fig. 9H). Spicules of tentacles consists of rods, perforated plates, tables, and C-shaped rods (Fig. 9 N–Q). Curved rods in tentacles in multiple different sizes; rough surface covered with spinelets especially dense at both ends. Perforated plates in tentacles spiny, rough surface covered with spinelets; some likens dichotomous rods (Fig. 9M). Tables and C-shaped rods in tentacles similar to ones found in the papillae (Fig. 9O, Q).

Remarks.

Stichopus vastus is the only species in Stichopus that have elaborate reticulated stripes covering the dorsal body with different density and intensity (Fig. 8). Massin (1999) and Massin et al. (2002) demonstrated this coloration varies for specimens from across different localities. The black transverse line in the area between bulges is also unique to this species. Massin et al. (2002) mentioned S-shaped rods were found in the dorsal body in small specimens, and the absent in larger specimens (>160 mm in body length). C-shaped rods in the tentacles of the present specimens were also mentioned by Cherbonnier and Féral (1984) but not by Massin (1999) and Massin et al. (2002). Prominent large perforated plates found in the dorsal papillae have not been reported from this species and they look like dichotomous branching rods found in the tentacles.

Distribution.

Indian Ocean, Andaman Islands, South China Sea, Indonesia, Thailand, Flores Sea, Great Barrier Reef Australia, Micronesia, Palau, Papua New Guinea ( Clark and Rowe 1971; Massin et al. 2002).