Mesothuria murrayi
Creators: name: Gebruk, Andrey V.
name: Solis-Marin, Francisco A.
name: Billett, David S. M.
name: Rogacheva, Antonina V.
name: Tyler, Paul A.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Echinodermata
Holothuroidea
Holothuriida
Mesothuriidae
Mesothuria
Mesothuria murrayi

description: Mesothuria murrayi (Théel, 1886)   
(Figure 11)  
 Holothuria murrayi – Théel, 1886a: 185–186, pl. 10, figs. 16–18.   
 Mesothuria murrayi (Théel, 1886) – Sluiter, 1901b: 24; Hérouard, 1902: 23–24; Fisher, 1907: 683–685, pl. 71, figs. 1a–h; Hérouard, 1912: 23–24; Ohshima, 1915: 226; Hansen, 1956: 45–46, fig. 14b, d, e; Jangoux et al., 1989: 163 (list), 165–166, text fig. 3, figs. a–d.   
 Holothuria murrayi var. parva – Théel, 1886a: 186–187, pl. 9, fig. 2; pl. 16, figs. 4–5; Perrier, 1902: 316; Augustin, 1908: 18–20, text fig. 14.   
 Mesothuria parva (Théel, 1886) – Ludwig, 1894; Fisher, 1907: 686–687, pl. 71, figs. 2a–c; Ohshima, 1915: 226; Thandar, 1984: 341–343, textfig. 63; 1992: 161–163, figs. 1a–h.   
 Mesothuria (Mesothuria) murrayi (Théel, 1886) – Heding, 1940: 333.   
 Mesothuria (Mesothuria) parva (Théel, 1886) – Heding, 1940: 119.   
 Material examined   
See Table 10.  
 Type material   
 Syntypes, NHM 86.10.2.176 (one specimen); NHM 86.10.2.178 (one specimen), HMS Challenger St. 300, 17 October 1875, 33 ◦ 42 ′ S, 78 ◦ 18 ′ W, 2502 m.   
 (Continued)   
 Type locality   
South-east Pacific, 2502 m.  
 Diagnosis   
After Théel (1886a): body elongated, more or less distinctly cylindrical, with mouth and anus almost terminal. Twenty tentacles. Each lateral ventral ambulacrum with numerous pedicels, larger of which seem to form continuous row along each side of body; remaining pedicels of unequal size, sparsely distributed over adjacent interambulacra. Median ventral ambulacrum with numerous minute, almost imperceptible, pedicels. Dorsal surface with few, small, scattered papilla-like pedicels. Dorsal as well as ventral interambulacra have only few minute ambulacral appendages in their middle line. Perisome thin, flexible. Calcareous ring well developed. One Polian vesicle. Respiratory trees well developed.  
Ossicles tables, consisting of more or less irregular, perforated disk, typically with six large holes around central hole, and spire of three rods and one transverse beam. Spire terminates in three rather long arms, free ends spinous or branched (Figure 11).  
 Remarks   
 The type material of M. murrayi comes from the Pacific, off the Chilean coast, at a depth of c. 2500 m. Hérouard’s M. rugosa from off the Cape Verde Islands is identical in detail to M. murrayi of Théel. This was first noticed by Deichmann, who surprisingly considered M murrayi as a junior synonym of M. rugosa, although the priority of Théel’s name is obvious. There is also a clear similarity between M. murrayi and Perrier’s M. maroccana from off Morocco, also known from the Caribbean, the east Gulf of Mexico and the north-east Atlantic (Billett 1988). The two species have identical ossicles, but there are some differences in the arrangement of the tubefeet that may well be an age variation, because Théel’s specimens were 240 mm long whereas those of Perrier were only 50 mm. Perrier has pointed out the similarities between his specimens and M. murrayi (var.?) known from Gibraltar. The similarity between M. maroccana and M. murrayi (var.?) was also noticed by Grieg (1921). Further confusion was created by Deichmann (1930, 1940, 1954), who gave the morphological details of M. murrayi (Théel) in her descriptions, but assigned her specimens, 40–60 mm long, from the West Indian seas, to M. maroccana Perrier. This group of species evidently requires further study. That is also true for M. murrayi var. grandipes. Illustrations of the ossicles of this species are lacking, but the size given for the table disks, 0.15–0.18 mm in the 80-mm long specimen, significantly exceeds that of the main ‘murrayi group’ (0.07–0.12 mm). Mesothuria murrayi has also been reported from the Indonesian seas, from 400–522 m (Sluiter, 1901b) (Figure 9).   
 Distribution   
Rather cosmopolitan (Figure 9), though many records are unreliable owing to confusion with other species (see remarks).  
 Bathymetric range   
Depth 245–6650 m, but not reliable either.
description: Published as part of Gebruk, Andrey V., Solis-Marin, Francisco A., Billett, David S. M., Rogacheva, Antonina V. & Tyler, Paul A., 2012, Review of the genus Zygothuria Perrier, 1898 and the Atlantic group of species of the genus Mesothuria Ludwig, 1894 (Synallactidae: Holothuroidea) with description of the new species Mesothuria milleri sp. nov., pp. 265-348 in Journal of Natural History 46 on pages 303-307, DOI: 10.1080/00222933.2011.638423, http://zenodo.org/record/5202428