Temparena trouspetita, Thandar, 2018

Thandar, Ahmed S., 2018, On some miscellaneous sea cucumbers (Echinodermata: Holothuroidea) in the collections of the South African Museum with three new species, Zootaxa 4532 (1), pp. 57-85 : 70-71

? Temparena trouspetita sp. nov.

( Figure 10 )

Material examined. SAMC-A 090917 ,: SM 123, South off Scottburgh, 30°33.04’ S, 30°48.06’ E, heavy dredge, 690 m, 10.V.1977, 2 spec.

Etymology. The name of this new species is with reference to the tiny holes in the central part of the body wall plates (Fr. trous = holes; petits = small).

Diagnosis. A species of probably Temparena presently known from two barrel-shaped juvenile, up to 3 mm long. Tentacles 10, ventral two reduced to insignificant stubs, large tentacles with only short branches. Tube feet mostly in ambulacra, in single rows per ambulacrum (?juvenile); Calcareous ring poorly calcified or underdeveloped. Polian vesicle single. Ossicles of body wall comprise tables and plates. Tables with oblong smooth disc perforated by four or more holes, terminal holes at each extremity; spire usually reduced, of two pillars joined at apex, terminating in two or more teeth. Plates smooth, elongate, irregular or rounded, multilocular, with minute central holes, others often partially occluded. Tube-feet with minute perforated rods and plates; end-plates absent. Tentacles with smooth, multilocular plates with serrated or spinous margins and small holes ( Figure 9E ).

Description. Both specimens minute, juvenile, larger (holotype—Figure 9A) only about 3 mm long, height 2 mm, mid-body width about 1 mm. Form barrel-shaped, mouth and anus sub-dorsal, tentacles retracted. Smaller specimen (paratype—Figure 9B) only 2.5 mm long, with retracted posterior end, but with extended tentacles of which 8 well developed and 2 reduced to inconspicuous stubs; large tentacles (of paratype) dendritic but with short branches. Colour in alcohol beige-grey. Tube feet situated in ambulacra, in single rows (?juvenile); holotype with few tube feet also in interambulacra; paratype with naked interambulacra. Anal teeth not observed. Calcareous ring of both specimens poorly calcified, with short radial processes, perhaps still in process of development. Polian vesicle single, stone canal not observed, gonad immature in holotype; absent in paratype. Respiratory trees well developed. Ossicles of body wall comprise tables and plates. Tables of holotype ( Figure 9C ) with an oblong disc perforated by four or more holes, terminal holes at each extremity usually smaller, disc 90 µm–120 µm, smooth, spire often reduced, up to 40 µm, pillars joined at apex, terminating in two or more teeth. Plates of body wall smooth, elongated, irregular or rounded, multilocular, with holes often occluded medially or marginally or both ( Figure 9D ). Tube-feet deposits as minute perforated rods and plates ( Figure 9F ), end-plates absent. Tentacles with smooth, multilocular plates, up to 100 µm, with serrated or spinous margins and small holes ( Figure 9E ).

Distribution. Only recorded from south of Scottburgh, South Africa, 690 m.

Remarks. It is regrettable that this well characterised form is represented only by a pair of juveniles, up to 3 mm in length. Despite this, the writer has no doubt that although their calcareous ring is absent or underdeveloped their combination of two-pillared tables and plates as body wall deposits, betray their generic identity. It is therefore here referred to the genus Temparena without much hesitation. However, it is pertinent that mature specimens with well-developed calcareous ring need to be found to definitely confirm the generic identity. Nevertheless, the tube-feet and tentacle deposits are identical to those of the type species of Temparena . While in T. chuni the table discs are usually quadrilocular, in the current specimens they are usually multilocular and the plates are extraordinary, unlike the elongated plates of the type species. Although both specimens are immature with poorly or undeveloped calcareous ring, its ossicles are so characteristic, unlike any other known dendrochirotid that I feel obliged to name this extraordinary form.

Figures

FIGURE 9. Thyone hirta Cherbonnier, 1970. SAMC-A090916. A. Specimen (entire) juvenile; B. Tables from body wall; C. Tables from tube feet; D. Tube feet end-plate; E. Part of calcareous ring (dorsal view).

FIGURE 10.?Temparena trouspetita n.sp. SAMC-A090917. A. Dorsal surface of holotype; B. Ventral surface of paratype; C– F. Ossicles of holotype (C. Body wall tables; D. Body wall plates; E. Tentacle plates; F. Tube feet ossicles). (C–F same scale).