dcsimg

Comprehensive Description

provided by Smithsonian Contributions to Zoology
Rhizotrochus flabelliformis

Flabellum latum.—Alcock, 1902a:31.

DESCRIPTION OF HOLOTYPE.—Corallum flabellate, with an S-shaped elongate calice 61.5 mm long and 18.2 mm wide (GCD: LCD = 3.38). Angle of rounded lateral edges 90°; inclination of straight to slightly concave thecal faces 18°. Holotype 35.6 mm tall, with a tiny unreinforced pedicel 1.2 mm in diameter. Corallum dense; theca worn and heavily encrusted with foraminifera, serpulids, and bryozoa, although original thecal color appears to have been reddish brown. Upper thecal faces arched and only slightly damaged. Two symmetrically arranged bundles of rootlets present, one on each lower thecal edge. Rootlets tightly fused into bundles 6–7 mm in diameter.

Septa hexamerally arranged in seven cycles according to the formula: S1–4>S5>S6>S7, the seventh cycle incomplete, having only 46 pairs of septa (284 septa total). S1–4 not exsert and have highly sinuous lower, inner edges. As in R. typus, the upper edges of the larger septa are very narrow near the calicular edge, forming a concave notch before widening into a broad septal lobe toward the center of the fossa. S5 not notched or sinuous, about width of S1–4. S6 about half width of S5; S7, when present, rudimentary. Septal granules large, about 0.1 mm tall.

Fossa deep and narrow, obscuring view of rudimentary columella.
license
cc-by-nc-sa-3.0
bibliographic citation
Cairns, Stephen D. 1989. "A revision of the ahermatypic Scleractinia of the Philippine Islands and adjacent Waters, Part 1: Fungiacyathidae, Micrabaciidae, Turbinoliinae, Guyniidae, and Flabellidae." Smithsonian Contributions to Zoology. 1-136. https://doi.org/10.5479/si.00810282.486

Biology

provided by World Register of Marine Species
azooxanthellate

Reference

van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO).

license
cc-by-4.0
copyright
WoRMS Editorial Board
contributor
Jacob van der Land [email]

Depth range

provided by World Register of Marine Species
228-1050 m
license
cc-by-4.0
copyright
WoRMS Editorial Board
contributor
Stephen Cairns [email]

Habitat

provided by World Register of Marine Species
slope

Reference

van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO).

license
cc-by-4.0
copyright
WoRMS Editorial Board
contributor
Jacob van der Land [email]