New taxa of Japanese and New Zealand Eurystomellidae (Phylum Bryozoa) and their phylogenetic relationships
Author
Gordon, Dennis P.
Author
Mawatari, Shunsuke F.
Author
Kajihara, Hiroshi
text
Zoological Journal of the Linnean Society
2002
2002-10-31
136
2
199
216
https://academic.oup.com/zoolinnean/article-lookup/doi/10.1046/j.1096-3642.2002.00020.x
journal article
5433
10.1046/j.1096-3642.2002.00020.x
61176e3b-9cfb-499f-be30-cfde91a58a48
0024-4082
4634178
INTEGRIPELTA NOVELLA
SP. NOV
.
(
FIG. 2A, B
)
Material examined
Holotype
:
ZIHU 02034
, from 43°3¢N, 140°35¢E, 0 m, the rocky tidal flat of
Kamekawa
,
Kikonai-cho
,
Shirabeshi Prefecture
,
Hokkaido
.
Paratype
:
ZIHU 02035
, same locality as holotype
.
Description
Colony encrusting, multiserial, unilaminar. Autozooids contiguous, quincuncially arranged,
0.39– 0.75 mm
long (0.52 ±
0.08 mm
),
0.33–0.45 mm
wide (0.39 ±
0.03 mm
). Gymnocystal frontal shield smoothsurfaced, somewhat convex, no umbo or carina, lacking fenestrae. Orifice somewhat hat-shaped, the anter high-arched with the proximal embayments rounded, the proximal rim of the poster gently and evenly concave or straight; the lateral excavations of the gymnocyst very well developed, occurring adjacent to the embayments and extending proximally, on one or both sides, for a considerable distance, often equivalent to half the zooid length. Orifice of maternal zooids dimorphic, though not always obviously so (
0.26–0.31 mm
wide at the proximal margin compared to that of autozooids 3/4
0.20–0.26 mm
); distal kenozooidal chamber forming a somewhat triangular cap, with a transverse to circular sloping shelf of interior wall and a small circular foramen. No basal porechambers, interzooidal communications comprising a row of uniporous septula along each lateral wall. Ancestrula not seen.
Etymology
From
novellus
(L.), diminutive of
novus
, new.
Remarks
Integripelta novella
closely resembles the
type
species,
I. bilabiata
, which, however, is much larger in size. According to
Soule
et al
. (1995)
, autozooids of
I. bilabiata
are
0.60–0.65 mm
long and
0.50–0.55 mm
wide with an orifice width of
0.30–0.32 mm
(hence the widths of zooids and orifices do not even overlap in the two species). Additionally, the shallow gymnocystal excavations in
I. novella
are proportionately very much longer whereas the kenozooidal foramen is tiny and surrounded by a broader area of interior wall.
Apart from those sources already mentioned,
Integripelta bilabiata
has been recorded or described by
Hincks (1882
,
1884
),
Robertson (1908)
,
O’Donoghue & O’Donoghue (1925
,
1926
),
Osburn (1952)
, and
Banta (1973)
.
Soule
et al
. (1995)
gave its range as Nootka Island, Alaska, through British Columbia to southern California and to Navidad Head,
Mexico
, at depths of
168–237 m
, but it has also been recorded intertidally (
McBeth, 1971
). It is also known from the Pleistocene of southern California (
Soule & Duff, 1957
).
Robertson (1908)
described the operculum of
I. bilabiata
in some detail — it appeared to be two-layered and, together with the distal rim of the orifice, the whole structure appeared to be superficially bilabiate. Judging from observations on
I. sextaria
(below) the ‘bilabiate’ appearance obtains in dried material, in which the distal vestibular wall may be accentuated if slightly protruding. While the operculum proper may be thin, a descending cuticular rim around its periphery can give the appearance of thickness. The orificial structure of
I. japonica
(below) is not known.
Distribution
Known with certainty only from the intertidal zone at the
type
locality in
Hokkaido
.