Mesothuria murrayi (Théel, 1886)

Mackenzie, Melanie, Davey, Niki, Burghardt, Ingo & Haines, Margaret L., 2024, A report of sea cucumbers collected on the first dedicated deep-sea biological survey of Australia’s Indian Ocean Territories around Christmas and Cocos (Keeling) Islands (Echinodermata: Holothuroidea), Memoirs of Museum Victoria (Mem. Mus. Vic.) 83, pp. 207-316 : 245-248

Mesothuria murrayi (Théel, 1886)

Holothuria murrayi Théel, 1886a: 185–186 , pl. 10, figs 16–18.

Mesothuria murrayi . — Sluiter, 1901a: 24. — Fisher, 1907: 683–685, pl. 71, figs 1, 1a–h. — Ohshima, 1915: 226. — Hansen, 1956: 45–46, fig. 14b, d, e. — Jangoux et al., 1989: 163 (list), 165–166, fig. 3: a–d. — SolÍs-MarÍn, 2003: 180–182. — Gebruk et al., 2012: 303–307 , fig. 11. — Wirawati and Setyastuti, 2021: 452, 455, fig. 2a, b.

Mesothuria murrayi var. parva Théel, 1886a: 186–187 , pl. 9, fig. 2, pl. 16, figs 4–5.

Mesothuria murrayi var. parva . — Augustin, 1908: 18–20, textfig.14. Mesothuria murrayi (var.?). — Théel, 1886a: 187, pl. 9, fig. 3. Mesothuria parva Théel, 1886 . — Fisher, 1907: 686–687, pl. 71, figs 2, 2a–c. — Ohshima, 1915: 226. — Thandar, 1984: 341–343, textfig. 63. — Thandar, 1992: 161–163, fig. 1a–h. — Samyn and VandenSpiegel, 2016: 471, fig. 13a, b. Mesothuria deani Mitsukuri, 1912: 40–42 , textfig. 9.

Material examined. NMV F296839 * (1) [IN 2021 V04 007] ; NMV F296848 * (1) [IN 2021 V04 016] ; NMV F308144 * (1) [IN 2022 V08 105] .

Diagnosis of IOT material. Light brown, elongated, cylindrical to semicylindrical specimens, typically medium to large, up to 18.5 cm long, 6 cm wide, 5.5 cm high ( NMV F296839 pre-preservation). Terminal to ventral mouth and terminal anus. Tentacles all retracted in IOT specimens (likely 20 but not dissected out). Complete cover of tube feet but very scattered and reduced mid-dorsal and mid-ventral, longer and more conspicuous in lateral bands along the sides of each specimen, with bands moving onto both dorsal and ventral surfaces. Ossicles variable tables, but typically tri-radiate made of a perforated base disc with elevated central primary cross and three pillars, joined by a single cross beam in the middle and again at the top. Topped by three spines/arms angled up or out and spinous at the tips (most broken off in our samples). Bases typically smaller (~110 μm) or larger (130 μm) discs, with central perforation and six or seven larger perforations. Smaller specimen ( NMV F296848) table base most typically ~100 μm with six large perforations plus some smaller perforations, and rarely (only one seen) ~90 μm table with many perforations and with four-pillared spinous spire lacking typical arms.

Remarks. Specimens key to M. murrayi using Gebruk et al. (2012). Specimens agree with the type description ( Théel, 1886a) for M. murrayi general body form, tube foot distribution, and most ossicles. Ossicles with longer arms/spines not seen here (though most were broken) and remaining ossicles also look like M. maroccana , though this species itself may be just an age variation of M. murrayi ( Gebruk et al., 2012) . NMV F308144 (fig. 25d–f) has the body form closest to the type specimens, with body almost cylindrical, anus terminal, and mouth virtually terminal. All three have flexible skin though not obviously thin as recorded for types. NMV F296848 (fig. 25g) is a much smaller, flatter specimen.

Distribution. Cosmopolitan.*

Full bathymetric range. 246–6650 m * (IOT records 781–3345 m).

Type locality. South-east Pacific Ocean (off Chile), 2502 m .

*Many records may be unreliable (see remarks above and Gebruk et al. 2012).

This species previously recorded from outside Cook’s Passage Queensland, west-central Pacific Ocean in AFD, and from Western Australia (off Perth), New South Wales, and east of Cape York Queensland in ALA (January 2024). This IOT material represents a geographic and bathymetric range extension for the species in Australia .

References. AFD (2024), ALA (2024), Gebruk et al. (2012), SolÍs-MarÍn (2003), Théel (1886a), Wirawati and Setyastuti (2021).