Truncatoflabellum mozambiquensis, Cairns, Stephen D., 2016

Cairns, Stephen D., 2016, A key to the genera and species of the transversely-dividing Flabellidae (Anthozoa, Scleractinia, Flabellidae), with a guide to the literature, and the description of two new species, ZooKeys 562, pp. 1-48 : 16

Taxon classification Animalia Scleractinia Flabellidae

Truncatoflabellum mozambiquensis sp. n. Fig. 7B

Types.

Holotype: Anton Bruun 7-372L, 25°07'S, 34°34'E, 112 m, grey sandy mud, USNM 91764. Paratypes: Anton Bruun 7-372L, 232 coralla, USNM 1283832; Anton Bruun 7-371F, 24°46'S, 35°18'E, 110 m, 1 specimen, USNM 91762; Anton Bruun 7-372J, 25°07'S, 34°34'E, 106 m, 28 specimens, USNM 91763.

Description.

The anthocyathus has straight, rounded thecal edges, having an edge angle of 39-60°; the face angle ranges from 22-28°. The largest specimen has a GCD of 26.5 mm, whereas the holotype measures 23.4 × 11.2 in calicular diameter, 24.5 mm in height, and 5.3 mm in greater scar diameter. The GCD:LCD ratio is 1.4-2.2; the H:GCD is 1.0-1.4; the GSC:GCD is 0.19-0.26, with the GSD up to 6.9 mm in length. One pair of very short (rarely more than 1 mm long) and often broken and worn thecal edges spines occur near the basal scar; another pair often is present more distally. The thecal faces bear low ribbing corresponding to the C1-3. The corallum, although worn, sometimes has a blackish color. The septa are arranged in five cycles: S1-3>S4>S5, mature coralla having 96 septa. The lower axial septal edges are highly sinuous, and merge into a rudimentary elongate columella. The upper outer septal edges are not notched. The fossa is deep and narrow, although almost all coralla examined were partially damaged, making observations of the septa and fossa tentative.

Anthocauli are rare, only four of the 262 (1.5%) specimens representing this juvenile stage. It is small, only about 4.1 mm in height with a circular attached pedicel 2 mm in diameter, and a distal calice 5-6 mm in greater diameter corresponding to the scar diameter of the anthocyathus. It has three cycles of septa.

Distribution.

Off southern Mozambique, 106-112 m.

Remarks.

As suggested by the key, Truncatoflabellum mozambiquensis is most similar to Truncatoflabellum martensii , but can be distinguished by its smaller basal scar, higher H:GCD ratio, rounded thecal edges, and tendency to have one (or occasionally two) pairs of thecal edge spines vs. three pairs for Truncatoflabellum martensii (Table 2).

Etymology.

Named for the country from which it was found.