dcsimg

Comprehensive Description

provided by Smithsonian Contributions to Zoology
Leptopenus discus Moseley, 1881

Leptopenus discus Moseley, 1881:205–208, pl. 14: figs. 1–4; pl. 16: figs. 1–7.—Cairns, 1979:37–38, pl. 3: figs. 4–7 [synonymy].—Not Leptopenus discus.—Squires, 1965:878, fig. 1 [=L. solidus Keller, 1977]; 1967:505.

Leptopenus irinae Keller, 1977:38–40, pl. 1: figs. 1–4, 6, text-fig. 2.

Not Leptopenus sp. cf. L. discus.—Cairns, 1982:9 [= L. antarcticus Cairns, 1989a].

DESCRIPTION.—Corallum discoidal and extremely fragile, the peripheral costal spines invariably broken during collection. Largest specimen 25 mm in diameter, the height varying from 1–4 mm, resulting in the relatively great range of D:H ratio of 5–17. Base flat, the costae alternating in position with septa. Septa and adjacent costae joined to one another by thin synapticular bridges, each separated by large pores up to 0.5 mm long and 0.25–0.30 mm wide. Six major costae radiate from a circular central region about 0.5 mm in diameter, each costa soon dividing twice resulting in 4 costae in each system. These 24 costae further subdivide to match the number of septa in the corallum and ultimately extend up to one-third the calicular radius beyond the synapticular region (Keller, 1977).

Septa hexamerally arranged in typical micrabaciid fashion (see Cairns, 1982, text-fig. 1), usually resulting in 72 septa. S1, only independent septa, bearing 4 or 5 slender, cylindrical (0.1 mm in diameter) spines up to 0.9 mm in height, united by a low septal webbing. S2 also originate at center of calice and bear 3 tall robust spines, the one closest to center quite large: up to 0.2 mm in diameter and over 1 mm in height, constituting the greatest height of the corallum. A high web unites the S2 spines. A pair of S3 diverge from each of the 6 S2 relatively near columella, their union with the S2 covered by a low canopy. Each S3 bifurcates one to three times, depending on the ontogenetic stage, resulting in 48–72 septa. Examined paratype of L. irinae from Vityaz-4158 (USNM 92435) relatively small (calicular diameter = 11.0 mm), having only 48 septa. All septal spines are obliquely oriented towards calicular edge, never curved inward toward columella, and restricted to central portion of corallum. Columella a spinose central mound, penetrated by 10–15 trabecular spines, each spine about 0.1 mm in diameter.
license
cc-by-nc-sa-3.0
bibliographic citation
Cairns, Stephen D. 1994. "Scleractinia of the temperate North Pacific." Smithsonian Contributions to Zoology. i-150. https://doi.org/10.5479/si.00810282.557.i

Biology

provided by World Register of Marine Species
azooxanthellate
license
cc-by-4.0
copyright
WoRMS Editorial Board
bibliographic citation
van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO).
contributor
Jacob van der Land [email]
contributor
Jacob van der Land [email]

Depth range

provided by World Register of Marine Species
2842-5000 m
license
cc-by-4.0
copyright
WoRMS Editorial Board
bibliographic citation
van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO).
contributor
Stephen Cairns [email]
contributor
Stephen Cairns [email]