Placotrochides frustum Cairns, 1979

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 : 24

Taxon classification Animalia Scleractinia Flabellidae

Placotrochides frustum Cairns, 1979 Fig. 12B

Placotrochides frusta Cairns, 1979: 152-153, pl. 29, figs 4-6, 8-9, map 43.

Placotrochides frustra : Zibrowius 1980: 159-161, pl. 81E-M.

Placotrochides frustum : Cairns 2004: 307 (key, nom. correct.).

New records.

CRYOS, Balgim CP85, 34°24'N, 7°39'W, 1378 m, 15 specimens, MNHN; Professor Logachev 37L 165, 16°54.014'N, 46°34.842'W, 2646-2705 m, 6 Mar 2015, 1, USNM 1295415, 1, IOM Moscow; Professor Logachev 37L 188, 17°08.470'N, 46°23.443'W, 2291-2327 m, 12 Mar 2015, 1, IOM Moscow.

Distribution.

Lesser Antilles, off northeastern Brazil, mid-Atlantic Ridge at latitude of Lesser Antilles, off Morocco, 497-2646 m.

Remarks.

The specimens reported herein from the mid-Atlantic Ridge are much larger than any previously reported, having a GCD up to 10.2 mm and a height of 13.9 mm, the calice having corresponding more septa, i.e., S1-2>S3>S4, 12:12:12, or 36 septa. The largest previously known specimen was only 5.0 mm in GCD and had 26 septa. They also represent a considerable depth range extension.