Mesothuria cathedralis Heding, 1940

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., Journal of Natural History 46, pp. 265-348 : 284-289

Mesothuria cathedralis Heding, 1940

( Figure 7 )

Mesothuria (Allantis) cathedralis – Heding, 1940: 336–338, text fig. 5, figs. 1–10.

Mesothuria (Penichrothuria) cathedralis – Heding, 1942a: 8–9, text fig. 8, figs. 1–5.

Mesothuria cathedralis Heding, 1940 – Gage et al., 1985: 196.

Material examined

See Table 6.

Type material

Syntypes, cat. no. ZMUC HOL39 , two specimens, Valdivia, St. 56, 13 September 1898, 3 ◦ 10 ′ N, 5 ◦ 28.5 ′ E, 2278 m .

Type locality

South-east Atlantic, 2278 m.

Diagnosis

After Heding (1940): mouth ventral or subventral, anus terminal. Tentacles 20. Calcareous ring well developed. One Polian vesicle.

Ossicles quadriradiate tables (rarely triradiate) with four, rarely three, long spinous arms on top of spire and disks with one or two crowns of eight perforations in each; spire relatively high (150 µm on plate 100 µm in diameter); arms from two-thirds to four-fifths of spire length ( Figure 7 ). Feet with end plate and small tables of same type as those in skin, sometimes deformed.

Remarks

Mesothuria cathedralis was well defined and carefully described by Heding. It is characterized by quadriradiate tables with four, rarely three, spinous arms on top of the spire and disks with one or two crowns with eight perforations in each; ossicles with the first full crown and few smaller additional perforations in the second crown are most common ( Figure 7A,B ).

The juvenile specimen reported by Gage et al. (1985) (23 mm long) has tubefeet all over the body, small ventrally and larger laterally. The ossicles are tables generally with eight holes in the base and with a tall spire ending in four points, which are almost smooth and not as thorny as figured by Heding (1940). Reduced tables are found in the tubefeet.

Distribution

In the east Atlantic ( Figure 6 ), including the Gulf of Guinea, off Cape Bojador ( Morocco), also in the Irminger Basin off southern Greenland and Gulf of Mexico.

Bathymetric range

Depth 1292–4930 m.

Figures

Figure 6. Distribution of a group of Mesothuria and Zygothuria species.

Figure 7. Mesothuria cathedralis Heding, 1940. Ossicles. (A–E) specimen from St. 72/386; (F–I) specimen from St. 71-A-8-10.