Flabellum thouarsii Mine Edwards & Haime, 1848

Cairns, Stephen D. & Polonio, Virginia, 2013, New records of deep-water Scleractinia off Argentina and the Falkland Islands, Zootaxa 3691 (1) : -

Flabellum thouarsii Mine Edwards & Haime, 1848

Figs. 3 N– O, 15

Flabellum thouarsii Milne Edwards & Haime, 1848: 265 , pl. 8, fig. 5.—Squires, 1969: 18, p. 6, map 4.—Cairns, 1982: 34–35, pl. 10, figs. 3–7 (complete synonymy).

Remarks. Flabellum thouarsii is quite similar to F. curvatum , and their ranges are sympatric as well. In time they may be shown to be the same species or recently evolved from a common ancestor. Cairns (1982) listed six morphological distinctions between the species. He also mentioned a difference in depth ranges, although the specimens reported herein invalidate the distinction based on depth. The other six criteria are also somewhat variable. In essence, the primary way to distinguish F. thouarsii is that it usually has a shorter and straight (vs longer and bent) pedicel, it has a straight corallum (that of F. curvatum is usually slightly curved in the plane of the LCD), it lacks the fine serration on the axial septal edge in the septal notch region (adjacent to the calice), whereas F. curvatum usually does have this fine serration on its larger septa, it has a flatter elliptical calice, and it usually has more epizootic animals attached to its theca.

Distribution. The distribution of F. thouarsii is essentially identical to that of F. curvatum ( Fig. 15), except for the outliers of southern Chile and South Georgia, at depths of 71–305 m (Cairns 1982); however, the records herein extend the known depth range to 1513 m, much deeper than previously known.

Material. PAT1108DR1, 4, MNCN; PAT1108DR10R, 1, MNCN; PAT1208DR2, 11, MNCN; PAT1208DR17, 9, MNCN; PAT0209DR3, 1, USNM 1193307; ATL09Lo45, 1, MNCN; ATL09Lo53, 2, MNCN; ATL10Lo89, 1, USNM 1193306; WH 336-66, 1, USNM 83382.

Figures

FIGURE 3. A – B, Crispatotrochus cornu, PAT 0209 DR 16, calicular and lateral views of corallum. C – G, Monohedotrochus capitolii: C, PAT 1008 DR 8, calicular view; D, PAT 0209 DR 11, calicular view; E – F, PAT 1008 DR 3, calicular and lateral views of corallum; G, PAT 0108 DR 11, calicular view. H – I, Desmophyllum dianthus: H, PAT 0108 DR 11, lateral view of corallum; I, PAT 1008 DR 4, calicular view of corallum attached to a stylasterid. J, Solenosmilia australis, holotype. K – M, Flabellum curvatum: K – L, ATL 09 Lo 66, lateral and calicular views of corallum; M, ATL 10 Lo 89, lateral view of straight corallum. N – O, F. thouarsii, ATL 10 Lo 89, lateral and calicular views of corallum with tissue.