Unomia complanatis Benayahu & Van Ofwegen & Ruiz Allais & Mcfadden 2021, gen. n.
Creators: name: Benayahu, Yehuda
name: Van Ofwegen, Leen P.
name: Ruiz Allais, J. P.
name: Mcfadden, Catherine S.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Cnidaria
Anthozoa
Alcyonacea
Xeniidae
Unomia
Unomia complanatis

description: Unomia complanatis gen. n. sp. n.
Figs. 6–11
Material. Holotype. Japan, ZMTAU CO 38120, Kumamoto Prefecture, Ushibuka, 32.1552°N, 130.0444ºE, 8 m, 18 September 2018, coll. C.S. McFadden. Paratypes: ZMTAU CO 38124, ZMTAU CO 38125, ZMTAU CO 38126, details as above. Additional material. Japan: ZMTAU CO 35154, Ryukyu Archipelago, Yonaguni Island, west Point, 16–22 m, 5 July 2010; Taiwan: ZMTAU CO 37813 (4 colonies), Green Island, Gong-Guan-Bi reef, 22°40’47.46” N, 121°29’24.42” E, 6.6–18 m, 2 October 2019, coll. Y. Benayahu; ZMTAU CO 37846 (4 colonies), Light House reef, Green Island, 22°40’31.38” N, 121° 27’42.90” E, 7.7–11.9 m, 3 October 2019, coll. Y. Benayahu.
Description. The holotype from Japan (ZMTAU CO 38120) is an encrusting flattened colony, 12–14 mm high and 20 X 25 mm in diameter (Fig. 6A). The stalk is not distinct as the polyps actually arise from the membranous base and leave almost no bare space down to the colony base. The polyp body is up to 4–5 mm long, and the tentacles are up to 2 mm long. The pinnules are fully contracted and seem to be arranged in 1–2 rows on each side also noted by tiny pits on the tentacles.
The sclerites are ellipsoid platelets 0.012 –0.017 X 0.018 –0.024 mm in diameter (Fig. 7A). They are composed of dendritic calcite rods, uniform in diameter of about 0.001 –0.002 mm, and their tips are either perpendicular or more or less parallel to the surface of the sclerite (Fig. 7B). The ethanol-preserved holotype is cream.
Variation. The preserved paratypes are smaller than the holotype. ZMTAU CO 38124 is an encrusting colony with almost no recognizable stalk (Fig. 6B). ZMTAU CO 38125 and ZMTAU CO 38126 (Fig. 6C, D), both have a distinct stalk bearing a polypary, the latter with a polyp emerging from its base. These characters are similarly confirmed by the underwater images (Fig. 10A). Sclerite forms and size ranges are consistent throughout all paratypes (Fig. 8A, B: ZMTAU CO 38124, not shown for ZMTAU Co 38125 and ZMTAU CO 38126).
The Yonaguni Island, Ryukyu Archipelago material (ZMTAU CO 35154) are small encrusting colonies, much resembling the holotype (ZMTAU CO 38120). The Green Island (Taiwan) material (ZMTAU CO 37813 and ZMTAU CO 37846) are all encrusting colonies as demonstrated both by the preserved (Fig. 9) and living colonies (Fig. 10B). The polyps of these colonies are arranged in several distinct groups corresponding to polyparies, whose number depends on the colony size. Their stalk is narrow, being only a few mm high. The sclerites of ZMTAU CO 37813 (Fig. 11) resemble those of the holotype (not shown for ZMTAU CO 37846).
Etymology. The species name is derived from the Latin: “complanatis”, flattened, and denotes morphology of the colonies. Gender: neuter.
Distribution. Japan, Taiwan.
description: Published as part of Benayahu, Yehuda, Van Ofwegen, Leen P., Ruiz Allais, J. P. & Mcfadden, Catherine S., 2021, Revisiting the type of Cespitularia stolonifera Gohar, 1938 leads to the description of a new genus and a species of the family Xeniidae (Octocorallia, Alcyonacea), pp. 330-344 in Zootaxa 4964 (2) on pages 337-338, DOI: 10.11646/zootaxa.4964.2.5, http://zenodo.org/record/4709507