Holothuria (Holothuria) tubulosa (s.s.) Gmelin, 1791

Mezali, Karim, Thandar, Ahmed S. & Khodja, Ihcene, 2021, On the taxonomic status of Holothuria (Holothuria) tubulosa (s. s.) from the Algerian coast with the description of a new Mediterranean species, Holothuria (Holothuria) algeriensis n. sp. (Echinodermata: Holothuroidea: Holothuriidae), Zootaxa 4981 (1), pp. 89-106 : 92-93

Holothuria (Holothuria) tubulosa (s.s.) Gmelin, 1791

Figure 2 , Table 4

Synonymy.

Holothuria tubulosa Gmelin, 1791, p. 3138 ; Grube, 1840, p. 35; Selenka, 1867, p. 323, pl. 18, figs. 42–43; Heller, 1868, p. 72; Marenzeller, 1874, p. 314; Ludwig, 1879, p. 570; Lampert, 1885, p. 76, fig. 34; Koehler, 1921, p. 174, fig. 130; Koehler, 1927, p. 215, pl. 16, fig. 25; Hérouard, 1929, p. 48; Nobre, 1931, p. 141, fig. 66, pl. 13; Panning, 1934, p. 77, fig. 60; Tortonese, 1934, p. 226; Tortonese, 1935, p. 261; Mayer, 1937, p. 15, figs. 5–6; Tortonese, 1952, p. 225; Cherbonnier, 1956, p. 22; Gustato & Villari, 1979, p. 107 –110, figs. 1–2; Tortonese, 1965, p. 53, figs. 16–17; Rowe, 1969, p.152 –154, fig. 17; Mezali, 1998, p. 59 –63, fig. 11.

Holothuria tremula Linnaeus, 1767, p. 1090 .

Holothuria columnae de Blainville, 1821, p. 316 .

Holothuria petagnae Delle Chiaje, 1824, p. 82 .

Holothuria maxima Delle Chiaje, 1823, p. 82 .

Holothuria columnae Delle Chiaje, 1824, p. 79 .

Remarks. The forms described below comply with the description of H. tubulosa by Koehler (1921) which description was recommended by Rowe (1969) for this species, in his excellent revision of the Holothuriidae . Thus, this form is here regarded as Holothuria (H.) tubulosa (s.s.).

Material examined. UF3847 ; UF5471 ; UF5476 ; UF3844 , Stidia , Algeria, 35°49.922’N, 0°1.174’O, 3 m, Summer 2006, 4 specs . UF5470 , Sidi-Fredj , Algeria, 36°45.000’N, 2°50.000’E, 0.5–10 m, Summer 2006, 1 spec. UF4471 , Banyuls-sur-Mer , France, 42°29.040’N, 3°7.970’E, 3 m, Summer 2006, 1 spec. UF5462 , Figuier-plage , Algeria, 36°46.750’N, 3°30.821’E, 0.5–10 m, Summer 2006, 1 spec. LPVCMRMS2020.201; LPVCMRMS2020.202, Ouillis , Algeria, 36°7.436’N, 0°15.219’E, 5 m, June 2020, 2 specs .

Description. Body form ( Figure 2 , Table 4 ) almost cylindrical, length up to 200 mm, width 30–60 mm when contracted. Body wall thick (about 7 mm) and leathery. Dorsal surface (bivium) ( Figure 2A ) rounded, bearing small conical tubercles/verrucosities, scattered, each terminating in a small, elongated papilla. Ventral surface (trivium) ( Figure 2B ) rounded in contracted state. Pedicels/tube feet numerous, crowded, no regular arrangement. Mouth ventral, surrounded by 20 tentacles; anus ventral, anal papillae well developed (5 series of 3 each, in each ambulacrum). Live colouration varying from light brown, red mahogany, to brown or black; ventral surface generally lighter (light brown). Longitudinal muscles about 8–9 mm in thickness. Cuvierian tubules absent. Stone canals 1–2. Polian vesicles several, 1–4 (if 4, one on middle and three on right side of dorsal mesentery), average length <10 mm. Tentacular ampullae about 8 mm long. Collar around mouth thin (about 1.30 mm). Calcareous ring not stout, radial plates ( Table 4 ) with broad anterior notch and only slightly concave posterior margin.

Ossicles. Ossicle types from the dorsal and ventral surfaces appear identical, they comprise tables and buttons. Tables ( Figure 2 Ca) small and four-pillared, average height of spire less than average diameter of disc. Disc slightly arched. Some tables with a thorny disc generally pierced with 4 large holes and a variable number of peripheral ones. Buttons ( Figure 2 Cb) appear oval in shape, about 101.25 and 73.75 µm long dorsally and ventrally respectively and 44.25 and 38.70 µm wide dorsally and ventrally respectively, not very thick but with a regular, rough surface with small, conical or pointed spines; holes average about 7, with a roughened periphery, arranged in two rows relative to the central axis of the button; holes may be partitioned, round, irregular in outline, but often become minute or even completely obliterated, then giving the buttons a solid but rough appearance. Average width of the holes of buttons 6.75 and 5.75 μm dorsally and ventrally respectively. Pseudo-buttons abundant but fenestrated ellipsoids scarce. Pedicels contain perforated plates, which are of two types; the first are enlarged ( Figure 2 Da), with large central perforations symmetrically arranged along the central axis, surrounded by other smaller perforations, the second type of plates are thick, rough and elongated ( Figure 2 Db) with an irregular outline and with only few large perforations at their lateral and terminal ends. The enlarged plates of the ventral surface have a smooth surface but an irregular and prickly outline and with two rows of large perforations symmetrically arranged along the central axis of the plate and surrounded by several smaller perforations. Tentacles present two forms of thick rods (19 µm); straight rods ( Figure 2 Ea) and those that are slightly arched ( Figure 2 Eb).

Figures

FIGURE 2. External morphology and ossicles of Holothuria (Holothuria) tubulosa (s.s.) (CMNI 2021–0195). A. Dorsal surface. B. Ventral surface. Ca. Tables of dorsal and ventral surfaces (SEM). Cb. Buttons of dorsal and ventral surfaces (SEM). Da. Enlarged plates of pedicels (one enlarged plate left with SEM and the 3 other in right with LM). Db. Elongated plate of pedicels (SEM). Ea. Straight rods of tentacles (LM). Eb. Slightly arched rods of tentacles (LM).