Protankyra sp.

THANDAR, AHMED S., 2007, Additions to the aspidochirotid, molpadid and apodid holothuroids (Echinodermata: Holothuroidea) from the east coast of southern Africa, with descriptions of new species, Zootaxa 1414 (1), pp. 1-62 : 56

Protankyra sp. indet.

Figure 25 (G–M)

Material examined

SAM-A27951 , off Matigulu Bluff , KZN, north coast, 29° 22.8' S, 31° 58.7' E , NMDP, St. ZR 13, 16 vi 1989, 520 m, posterior fragment only .

Description

Specimen 162 x 10.5 mm, cylindrical, lacking anterior end. Colour dull yellowish-white with dark specks due to adhering debris. Body wall translucent; intestine looped, posterior filled with globigerina. Ciliary urns solitary ( Figure 25J ).

Body wall spicules as anchors, anchor plates and bifurcate rods; radial muscles with miliary granules. Anchors ( Figure 25G ) slender, arms with 7–18 serrations each, not reaching tip of arm ( Figure 25M ), vertex smooth, convex, stock bilobed, each lobe finely branched, denticles absent ( Figure 25L ); anterior anchors 760–900 µm (mean 840 µm), distance between arms 460–550 µm (mean 490 µm); posterior anchors longer, 930–945 µm (mean 935 µm). Anchor plates oval ( Figure 25I ), narrower anteriorly, margins irregular, number of holes in front of bridge usually less than 60, increasing in size anteriorly, larger holes dentate, teeth 1–6, bridge well formed, reticulate, with reticulum obscuring the smaller posterior holes; anterior plates 515–630 µm (mean 575 µm) long, 400–480 µm (mean 443 µm) wide; posterior plates larger 600–730 µm (mean 653 µm) long, 395–515 µm (mean 477 µm) wide. Accessory deposits as anteriorly located curved, bifurcate rods, 58–75 µm (mean 65 µm), with 1–2 short projections ( Figure 25K ). Miliary granules of radial muscles ( Figure 25H ) as smooth, 20–40 µm (mean 30 µm) lenticular bodies..

Distribution Northern KZN, South Africa, 520 m.

Habitat Mud and clay lumps.

Remarks

The specimen, although incomplete, possesses several characters in combination, making it distinct from any other nominal species of the genus. Once complete specimens become available a new species may need to be erected. Of the approximately 45 nominal species of the genus known to date, the present material comes closest to P. errata Koehler & Vaney, 1905 , P. buitendijki Rowe, 1983 , P. dubia Cherbonnier, 1965a and P.similis ( Semper, 1868) . It differs from P. errata in the absence of spines on the vertex and the complexity of the bridge; from P. buitendijki in the absence of denticles on the stock, the shape of the anchor plates and the presence of many more dentate holes; from P. dubia in the shape of the arm serrations, absence of denti- cles on the stock and the presence of bifurcating rods as accessory deposits; and from the brackish water P. similis by its habitat, the bilobed and branched nature of the stock, absence of denticles on the stock, presence of toothed holes in the anchor plates and miliary granules in the radial muscles. Table 1 summarises the differences in distribution, depth, size and spicules of the five species here considered.

Figures

FIGURE 25. (A–F) Protankyra autopista (Marenzeller, 1881). SAM–A27950. A. anchors from body wall; B. anchor plates from body wall; C. miliary granules from longitudinal muscle; D. buttons from body wall; E. rods from tentacle tip; F. rods and granules from tentacle stalk. (G–M) Protankyra sp. SAM-A27951. G. anchor from anterior body wall; H. military granules from longitudinal muscle; I. anchor plate; J. ciliary urns; K. rods from anterior body wall; L. enlargement of anchor stocks; M. enlargement of anchor arms. (A–F & H scale a; G & I scale b; L & M scale c; K scale d)