Thyone venustella Ludwig & Heding, 1935

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 : 9-12

publication ID	https://doi.org/ 10.11646/zootaxa.1697.1.1
DOI	https://doi.org/10.5281/zenodo.5107103
persistent identifier	https://treatment.plazi.org/id/DE2087C7-F528-874D-A0AD-F79E97D95EAA
treatment provided by	Felipe
scientific name	Thyone venustella Ludwig & Heding, 1935
status

Treatment

Thyone venustella Ludwig & Heding, 1935 View in CoL

Figures 4E–K View FIGURE 4 & 5 View FIGURE 5

Thyone venusta Schmidt, 1926: 125 View in CoL , fig. b.

Thyone venustella Ludwig and Heding, 1935: 203 View in CoL , pl. 2, figs. 15–20.

Havelockia venustella Thandar, 1989: 292 , figs. 2 & 9a (syn. and records).

Type Perhaps in Bonn , Germany .

Type locality Agulhas Bank, WCP, 155 m.

Material examined

SAM-A27982, UCT Ecol. Surv., St. SCD 203 , 34 o 51' S, 23 o 41' E, 30.xi. 1960, 183 m, 5 spec. (including fragments); SAM-A27983, St. SCD 234 , 34 o 51' S, 23 o 4' E, 30.xi. 1960, 183 m, 1 spec; SAM-A27984, St. SCD 269 , 34 o 23' S, 25 o 54' E, 19.vii. 1961, 182 m, 15 spec. (including fragments); Still Bay Shelf Transect , St. 1, 2, 35 o 22' S, 22 o 31' E, 20.vi. 1972, 200 m, 5 spec. (including 2 juvenile), SAM-A27755, WCD 140 (no further data), 11.ix.1962, 1 spec. (juvenile) GoogleMaps .

Description

Largest specimen 32 mm; colour off-white; anal teeth present. Calcareous ring, here illustrated for the first time, only present in an adult from Still Bay and juvenile ( SAM A27755) from St. WCD 140, ring of adult ( Figure 5F View FIGURE 5 ) partially damaged but typically of Thyone type - elongated, tubular, mosaic-like. Body wall tables of adult ( Figures 4E, F View FIGURE 4 & 5C, D View FIGURE 5 ) scarce, typically confined to anal region, with 4-5(12)-holed disc, 30-40 µm, with thin margins; spire low, terminating in two clusters of teeth, tables sometimes distorted. Podia with endplates (about 70 µm) ( Figures 4G View FIGURE 4 & 5E View FIGURE 5 ) but no supporting deposits. Juvenile 6 mm, whitish, podia scattered, more numerous radially, with some indication of arrangement in double rows; calcareous ring ( Figure 4K View FIGURE 4 ) not fully calcified, except for anterior projections and paired posterior processes; Polian vesicle single; stone canal straight, madreporite elongate; tables ( Figure 4H View FIGURE 4 & 5A View FIGURE 5 ) with 4- 5 or fewer holed disc; tentacles with developing perforated plates ( Figure 5I View FIGURE 5 ); introvert with elongated, small-knobbed, multilocular plates with irregular margins ( Figure 5H View FIGURE 5 ).

Distribution Lambert’s Bay to just east of Cape St. Francis, WCP, 155- 400 m.

Remarks

Because of the poor description of the calcareous ring by Ludwig and Heding (1935), Thandar (1989) dubiously retained the species in Havelockia , the genus in which Panning (1949) initially included the species, thus overlooking the addendum of Panning’s paper, in which he transferred all his Havelockia species , except the type species, back to Thyone . Thandar, however, added some notes and recorded the dimensions of the spicules. Most materials thus far examined by the writer (at ZMUC, the UCT Ecol. Surv. materials at the SAM identified by Ahearn, and the current specimens previously examined by Natasen Moodley 2000) all lack a calcareous ring except for the two specimens described above. The ring is definitely of the Thyone type. Thandar’s (1989) viewpoint that T. propinqua Cherbonnier from shallow-waters of south-west WCP, might represent juvenile of T. venustella is no longer upheld (see remarks under T. propinqua above).