Paracucumaria sp.

Thandar, Ahmed S., 2008, Additions to the holothuroid fauna of the southern African temperate faunistic provinces, with descriptions of new species, Zootaxa 1697 (1), pp. 1-57 : 30-33

Paracucumaria sp. indet.

Figure 12

Material examined

SAM-A28013, UCT Ecol. Surv., Still Bay Shelf Transect , St. SST 12, 35 o 22 S, 22 o 31 E, 20.vi. 1972, 200 m, 1 spec.

Description

Specimen small, barrel-shaped to sub-globose, badly distorted so much so that dorsal surface appears right lateral; mouth and anus dorsal, difficult to demonstrate, siphons absent. Length 3.5 mm, breadth in mid-body 2.75 mm. Colour uniformly pale yellowish-white to cream. Podia well developed, smaller dorsally, in single rows except anteriorly where they occur in two rows; ventral podia longer, in two rows, except anteriorly where they occur in three rows; interambulacra naked except anteriorly where the podia form a cluster around mouth. Tentacles 10, retracted, eight large, ventral-most two drastically reduced, large tentacles broadly branched at base, each primary branch with short lateral branches. No anal teeth nor specialized anal papillae. Skin soft, thin, invested in scales, dorsally and ventrally.

Calcareous ring ( Figure 12F ) without posterior processes, radial and interradial plates only fused at base, both more or less of equal length, radial plates anteriorly bifid, with depression for attachment of retractor muscle and deep posterior concavity, interradial plates triangular with shallow posterior concavity. Polian vesicle single, sac-like, ventral; stone canal short, madreporite bean-shaped ( Figure 12F ), lodged in concavity of mid-dorsal interradial plate. Intestine in a single loop. Gonad absent. Each respiratory tree with two main branches, one shorter than the other, each branch with sac-like extensions, better developed terminally. Longitudinal muscles thin, retractors originating in region of mid-body.

Spicules of dorsal and ventral body wall similar, comprising large (200-270 µm), finely-knobbed plates/ scales ( Figure 12A ) with smooth margin, up to 20 holes and 5-30 tiny knobs, mostly with one end narrowed and denticulate, large ones not obviously denticulate but with narrower portion heavily knobbed and irregular, plates often broken or still developing. Podial deposits as much smaller (ca. 56 µm), knobbed, perforated plates with a lesser number of holes, and elongated rods (ca. 70 µm) with terminal and/or central perforations ( Figure 12B ). Tentacle stalks with plates similar to those of podia ( Figure 12D ) (ca. 142 µm), tentacle branches and tips with smaller (50 µm), slightly-knobbed, irregular, delicate plates ( Figure 12C ). Introvert spicules (77-110 µm) similar to those of podia and tentacle stalk, usually with four holes and marginal knobs ( Figure 12E ).

Distribution Known only from Still Bay, south Western Cape Province.

Remarks

The single specimen at hand is probably juvenile judging from its size and the absence of gonad. Thandar (1998) compared all the nominal species of Paracucumaria known then. From this it appears that the single specimen comes quite close to the shallow-water (24 m) P. deridderae Massin, 1993 from Mauritania, differing from it in its size (perhaps due to its immaturity), absence of posterior bifurcations to the radial plates and different kinds of podial, tentacle and introvert deposits. However, its body wall spicules are virtually indistinguishable from those illustrated for P. deridderae . It is for this reason the material is here referred to Paracucumaria , an essentially east Atlantic genus, but because of its singularity and immaturity it is not named.

Figures

FIGURE 12. Paracucumaria sp. indet. SAM-A28013. A. plates from body wall; B. plates and rods from lateral podia; C. plates from tentacle tips; D. plate-like rods from tentacle stalk; E. plates from introvert; F. calcareous ring and madreporite. A-E scale a.