Phyllostauros vercoi ( Joshua and Creed, 1915 )

O’Loughlin, P. Mark, Barmos, Shari & VandenSpiegel, Didier, 2012, The phyllophorid sea cucumbers of southern Australia (Echinodermata: Holothuroidea: Dendrochirotida: Phyllophoridae), Memoirs of Museum Victoria 69, pp. 269-308 : 288

Phyllostauros vercoi ( Joshua and Creed, 1915)

Figures 11 , 12

Thyone vercoi Joshua and Creed, 1915: 19–20 , pl. 2 figs 2–4, pl. 3 fig. 1, pl. 4.—H. L. Clark, 1938: 463–464.

Phyllophorus ventripes Joshua and Creed, 1915: 19 , pl. 2 fig. 1, pl. 3 fig. 5. (part).

Lipotrapeza ventripes .—H. L. Clark, 1938: 495–496.—H. L. Clark, 1946: 412.— Heding and Panning, 1954: 175, fig. 83 (from Joshua and Creed 1915).— Rowe, 1982: 464.— Rowe and Gates, 1995: 311. (part).

Staurothyone vercoi .—H. L. Clark, 1946: 397–398.—A. M. Clark, 1966: 345.— Rowe and Gates, 1995: 281.

‘Staurothyone’ vercoi .— Rowe, 1982: 464, fig, 10.29b.

Material examined. Holotype. South Australia, SAM K517 (with microscope slides of “skin”, tentacle, and pharynx; specimen strongly contracted, dry).

Phyllophorus ventripes Joshua and Creed, 1915 . Holotype. South Australia coast, SAM K1374 (specimen dry; oldest labels “type M.S.S.”, “ Phyllophorus sp. n. type”, “ holotype ”; determined as “ Sturothyone ” vercoi by F. W. E. Rowe 1977). Paratypes. South Australia coast, 18 Sep 1913, NMV F45143 (3; no. 60676–8; labelled syntypes; determined by Joshua and Creed in 1914; from SAM “in exchange” 19 Sep 1919; AM label “ Staurothyone ” vercoi ; judged here to be paratypes).

Diagnosis. Up to 50 mm long, up to 15 mm diameter (preserved, tentacles withdrawn), cylindrical body tapered to rounded slightly upturned ends orally and anally, distinct ventral surface, thick firm body wall; external anal scales not detected; 20 tentacles, 5 large pairs alternating with 5 small pairs; complete cover of tube feet, larger and concentrated ventrally, disc ends about 0.7 mm diameter, smaller and scattered dorsally, orally, anally, disc ends about 0.4 mm diameter; tube feet cross introvert; calcareous ring with 10 posterior composite digitiform projections arising jointly from both radial and inter-radial plates, projections each comprise about 6 end-toend plates, projections close radially creating long narrow gap extending higher anteriorly into the radial plates than the wide inter-radial gap, ring not tubular, posterior prolongations sub-equal in length with plates and anterior projections, form of plates and composite components variable; short stone canal, multi-lobed madreporite close to vascular ring; 1 tubular polian vesicle; longitudinal muscles with mid-muscle groove; gonad tubules in series along gonoduct on each side of dorsal mesentery, not branched.

Mid-body wall with abundant crosses, typically 64 µ m long, some with 1 or 2 blunt surface spines near bifurcate ends, rare large crosses 88 µ m long with bifurcations joined to create large perforations; tube foot ossicles endplates and support rods only, endplates with denticulate margin, irregular perforations similar size, diameters up to 320 µ m, endplate support ossicles predominantly dumbbell-shaped, up to 104 µ m long, rounded ends with large and small perforations and denticulate margin; tentacles with rods and rosettes, larger rods dumbbell-shaped, widened and perforate distally with denticulate margin, up to 240 µ m long, rosettes up to 40 µ m long; pharynx with abundant rosettes, typically 32 µ m long.

Colour. Body red-brown, rusty, not darker orally and anally; tube feet disc ends off-white; tentacles with white lumps (rosettes), trunks white, branches pale brown.

Distribution. South Australia, Gulf St. Vincent, intertidal and offshore sediments.

Remarks. The new generic referral and unique diagnostic characters of Phyllostauros vercoi ( Joshua and Creed, 1915) are discussed above under the new genus Phyllostauros O’Loughlin.

As the basis of their erection of this new species Joshua and Creed 1915 refer specifically to a single specimen collected by Dr. J. C. Verco, “considerably contracted” and 36 mm long (SAM K517). H. L. Clark 1938 refers to a loan of two specimens of Thyone vercoi , 50 and 14 mm long. He further notes that both came from Le Fevre Peninsula (15 km NW of Adelaide in Gulf St. Vincent), and thus from sandy shallows. Curiously H. L. Clark 1946 makes no mention of these two specimens in discussing Staurothyone vercoi .

The two oldest labels with the holotype specimen of Phyllophorus ventripes (SAM K1374) record “type M.S.S” and “type, SA coast, Dr. Verco”. Other recent labels indicate “ holotype ”. Rowe and Gates 1995 record “ holotype ”. We accept that this specimen is the holotype. A determination by F. W. E. Rowe in 1977 indicates ‘Staurothyone’ vercoi . We agree with this species determination and synonymy. Although the specimen is dry it is still possible to extract cross ossicles from the body wall.

Furthermore we have found that the three paratypes of Phyllophorus ventripes Joshua and Creed 1915 (NMV F45143) are conspecific with Thyone vercoi (type status of paratypes discussed above under Lipotrapeza thyonoides ).

The holotype specimen of Thyone vercoi is dry and in poor condition but there is an excellent set of slides from the type available. The species itself has unique characters within Phyllophoridae , has never been uncertain in terms of type status, has not been erroneously reported in the literature, and has received considerable attention in the literature (see above under Phyllostauros ). On the other hand, for Phyllophorus ventripes , considerable confusion has surrounded the history of the status and identity and description of the type specimens, and subsequent determination of other material. Thus as “first revisers” (see ICZN Article 24.2.2) we give name precedence to Thyone vercoi over Phyllophorus ventripes in Joshua and Creed 1915. Phyllophorus ventripes is a subjective junior synonym of Thyone vercoi .

Figures

Figure 11. Photos of preserved specimens of Phyllostauros vercoi (Joshua and Creed, 1915). a, lateral view showing tube feet close ventrally and ventro-laterally, and sparse dorsally (paratype of Phyllophorus ventripes Joshua and Creed, 1915; NMV F45143) (insert: form of the calcareous ring plates); b, calcareous ring (NMV F45143); c, ventro-lateral view (holotype of Phyllophorus ventripes Joshua and Creed, 1915, dry, oral end detached, SAM K1374); d, calcareous ring (SAM K1374).

Figure 12. SEM images of ossicles of specimen of Phyllostauros vercoi (Joshua and Creed, 1915) (from paratype of Phyllophorus ventripes Joshua and Creed, 1915; NMV F45143). Surface-knobbed crosses from the body wall.