Sixteen new generic records of Korean Bryozoa from southern coastal waters and Jeju Island, East China Sea: evidence of tropical affinities
Author
Yang, Ho Jin
Author
Seo, Ji Eun
Author
Gordon, Dennis P.
text
Zootaxa
2018
4422
4
493
518
journal article
30030
10.11646/zootaxa.4422.4.3
d2c5d8c4-d2e2-44a7-add4-3a94812d2581
1175-5326
1253219
45E16185-7EE6-4768-88DF-6ACA1D29DCE4
Corbulella boninensis
(
Silén, 1941
)
(
Figs 6, 7
)
Pyrulella corbula
:
Harmer 1926
: 225
, pl. 14, fig. 4;
Mawatari 1965
: 601
, fig. 53a, b;
Mawatari & Mawatari 1980
: 82
, fig. 26.
Non Membranipora
corbula
Hincks, 1880
.
Pyrulella boninensis
Silén, 1941
: 26
, figs 21–24.
Corbulella boninensis
:
Gordon 1984
: 30
.
Material
examined.
Two
colonies (NIBRIV0000805881, MBRBKW2),
Munseom Island
,
Jeju
,
20 m
, collected by
Ho Jin Yang.
Description.
Colony encrusting, multiserial, unilaminar, unpigmented, up to
21 mm
across. Autozooids roughly elongate-oval to subpyriform, longer than wide. Cryptocystal rim elongate-oval, highest part of zooid, granular, a little wider proximally, negligible distally, with minutely ridged margin. Gymnocyst smooth, narrow laterally, more-developed proximally, bearing 12–14 spines; 5–6 spines bordering orifice, proximalmost pair erect, the others leaning slightly outwards; 6–8 periopesial spines all slightly curving over membranous frontal wall, but not as far as zooidal midline.
Avicularium vicarious, with large lingulate rostrum and mandible, entire rim of rostrum strongly toothed, delimited from avicularian opesia by stout, projecting pivots; opesial cryptocyst granular, margin with 4–5 spines. Many vicarious avicularia produced by reparative budding within former autozooidal cystids, rarely vice versa.
Ooecia prominent, occupying gymnocyst of distal zooid; ectooecium smooth, calcified except for broad, crescentic membranous area covering tabula exposing smooth endooecium, apical margin of ectooecium rising to peak, frequently projecting as hollow spine. Only a pair of proximal oral spines in ovicellate zooids, and typically 7 periopesial spines.
Ancestrula not seen.
Measurements.
ZL 426–607 (489) µm; ZW 242–318 (285) µm; OrL 275–404 (326) µm; OrW 155–217 (187) µm; AvL 424–662 (559) µm; AvW 265–349 (307) µm; OoL 92–156 (118) µm; OoW 274–350 (319) µm.
Remarks.
The present material accords well with Silén’s (1941) species, the name of which has been long neglected in the northwest Pacific in favor of
Corbulella corbula
(or earlier combinations).
Corbulella corbula
(
Hincks, 1880
)
has been accorded a wide range in the western Pacific, but the
type
locality is in southeastern
Australia
and the oral spines, as illustrated by
Bock (2008)
and
Gordon (1984
,
1986
), are long and stout. The material illustrated by
Ryland & Hayward (1992)
from Heron Island, Great Barrier Reef, may be allied to Silén’s species, but these authors described the rostral rim of the vicarious avicularium as smooth instead of strongly toothed. It is likely that there are cryptic species mistaken as
C. corbula
in the western Pacific.
Distribution.
Japan
: Ogasawara Islands; Honshu (Misaki and Mutsu Bay).
Korea
:
Jeju
Island. Depth range
20–
120 m
.