Intertidal Bryozoa from Korea — new additions to the fauna and a new genus of Bitectiporidae (Cheilostomata) from Baengnyeong Island, Yellow Sea
Author
Min, Bum Sik
Author
Seo, Ji Eun
Author
Grischenko, Andrei V.
Author
Gordon, Dennis P.
text
Zootaxa
2017
4226
4
451
470
journal article
37251
10.11646/zootaxa.4226.4.1
8903776b-ace3-4ff6-aa28-635145d78260
1175-5326
265060
64B19A58-BBB5-4858-833F-F7937C3A351F
Cauloramphus dicki
n. sp.
(
Figs 2–5
)
Cauloramphus
‘Korea Baeng. sp. 1’:
Dick
et al
. 2013
: 33
, 40, 41.
Etymology.
Honorific for Dr Matthew H. Dick,
Hokkaido
University,
Japan
, who has greatly advanced knowledge of bryozoans in the North Pacific, especially the genus
Cauloramphus
.
Material examined.
Holotype
:
NIBRIV0000325931,
Yeonhwa-ri
,
37.9378° N
,
124.6233° E
, Baengnyeong
Island
,
27 November 2007
, low tide, collected by
B.S. Min
and
A.V. Grischenko
.
Paratypes
:
NIBRIV0000711262, same collection data as for the
holotype
. Other material: Woosuk University collection—Baengnyeong
Island
: Dumujin (27 colonies), Yeonhwa-ri (21 colonies), mostly on rocky substrata, but also on plastic debris, shell and crustose coralline algae (
Clathromorphum
).
FIGURES 2–5.
Cauloramphus dicki
n. sp.
, Yeonhwa-ri.
2,
Part of an unbleached colony with periopesial spines and three claviform avicularia (arrows); scale bar, 200 µm.
3,
Frontal view of the mandible and opesial frontal membrane of an avicularium; scale bar, 20 µm.
4,
Non-ovicellate zooids with periopesial spine bases; scale bar, 100 µm.
5,
An entire autozooid and parts of neighbours showing two vestigial ooecia, each with a distal extension between a pair of spines; arrows indicate a flattened area of interior wall and a pore; scale bar, 200 µm.
Description.
Colony encrusting, unilaminar, up to
20 mm
in diameter, brownish when dried. Autozooids contiguous, arranged in quincunx, more or less elongate-oval and tending to be widest in proximal half; interzooidal boundaries clearly defined by furrows. Gymnocyst very narrow laterally or not evident in frontal view, slightly developed proximally or not at all, smooth, bearing 10–16 periopesial spines; these more or less straight, obliquely angled part way across opesia; distalmost 3–5 spines stouter and more vertical; spine bases not dark. Cryptocystal rim inside and between periopesial spine bases, coarsely granular-tubercular except in distal quarter, of same width throughout except distally where it is narrowed to the point of absence. Opesia large, oval. Operculum comprising a transversely D-shaped flap, somewhat high-arched, at distal end of membranous frontal wall. Avicularia single or paired, fusiform in frontal view, asymmetrically clavate in lateral view, placed between the 2nd and 3rd, or 3rd and 4th, periopesial spines on either side, the mandibular-opesial surface steeply slanted, facing proximolaterally; rostrum and mandible acute; basal stalk of avicularium cuticular. Ooecium vestigial, comprising a small transversely arcuate structure with a flattened area of interior wall and a tiny pore, having 1–4 short distal lobes between spine bases. Communication pore areas in open-fronted pore-chambers along the base of the distolateral walls, with 1–2 such chambers mid-distally and 2–3 on each side distolaterally. Ancestrula not seen.
Measurements.
ZL, 358–474 (410) µm; ZW, 230–313 (276) µm; OpL, 279–341 (301) µm; OpW, 144–198 (174) µm.
Remarks.
Cauloramphus dicki
n. sp.
is very similar to material from Akkeshi Bay,
Hokkaido
,
Japan
, attributed by
Grischenko
et al
. (2007)
to
Cauloramphus spinifer
(
Johnston, 1832
)
, a species first described from Britain that is nominally widespread in the northern Pacific (Dick & Ross 1998;
Grischenko
et al
. 2007
). The specimens from
Japan
have the same total number of spines, similar avicularia (though less elongate), and the same relative proportions of gymnocyst and gymnocyst, but the vestigial ooecium is different. Whereas it is smooth and concave with a crest in putative
C. spinifer
from
Hokkaido
(
Ostrovsky
et al
. 2007
), that in
C. dicki
is flattened, with lobes extending between spine bases.
Furthermore, in a study comparing morphological divergence with genetic distance using cytochrome c oxidase I (
COI
) sequences,
Dick
et al
. (2013)
showed that material from Baengnyeong
Island
here named as
C. dicki
was isolated from
C. spinifer
in the gene tree. It should be noted that the vestigial ooecium of
C. spinifer
from Europe has not been described, nor have
COI
sequences been obtained, so it remains to be demonstrated that this species really is in the
North Pacific.
[In passing, it should be noted that the specific epithet is sometimes rendered
spiniferum
(e.g.
Hayward & Ryland 1998
), but, whereas
rhamphos
(Greek, curved beak or bill) is neuter in gender, the Latinized form of the noun is masculine, hence
spinifer
is the correct spelling, as in several authors from
O’Donoghue & O’Donoghue (1926)
to
Grischenko
et al
. (2007)
.]
Distribution.
Korea
: Baengnyeong
Island
.
Japan
: Akkeshi Bay,
Hokkaido
; low intertidal on hard substrata.