New seamount- and ridge-associated cyclostome Bryozoa from New Zealand
Author
Gordon, Dennis P.
National Institute for Water & Atmospheric Research, Private Bag 14901 Kilbirnie, Wellington, New Zealand
Author
Taylor, Paul D.
Department of Palaeontology, Natural History Museum, Cromwell Road, London SW 7 5 BD, UK. E-mail: pdt @ nhm. ac. uk
text
Zootaxa
2010
2010-07-12
2533
1
43
68
https://biotaxa.org/Zootaxa/article/view/zootaxa.2533.1.3
journal article
10.11646/zootaxa.2533.1.3
1175-5326
5303533
Plagioecia parva
n. sp.
(
Fig. 7 A–D
)
Material examined.
Holotype
:
NIWA 61248
, from cruise TAN0413,
Stn
129, 37°20.40–
37°20.25’S
, 177°06.69–
177°06.81’ E
,
Bay of Plenty
, on
Mahina Knoll
northwest of
White Island
,
275–335 m
depth
, collected
14 November 2004
.
Paratypes
:
NIWA 61249
, same locality as holotype
.
Distribution.
Continental slope, central
Bay of Plenty
,
New Zealand
,
275 m
.
Etymology.
From Latin
parvus
, small.
Description.
Colony encrusting, more or less circular, central disc of zooids
1.90–2.24 mm
diameter, with a broad, thin peripheral lamina that may increase overall colony diameter up to
3.08 mm
. One or two small subcolonies able to develop at the colony margin in the zooidal budding zone. Autozooidal peristomes longest behind the peripheral budding zone, up to
0.37 mm
high; apertures circular to oval,
0.06–0.10 mm
in diameter, those in broad central zone comprising only short rims, the zooidal tubes all sealed with finely porous calcareous diaphragms. Zooids with peristomes separated or several peristomes more or less connate in short radial rows; centralmost zooids somewhat spirally disposed; surface calcification of colony between peristomes with fine, wavy, growth lines. Peristomial interiors lacking mural spines.
Gonozooid at colony periphery, brood chamber transversely elongate and broadly crescentic, tapering somewhat on each side laterally,
1.28 mm
wide, up to
0.45 mm
long; ooeciostome mid-distal, forming a short tube bent towards the colony centre, the ooeciopore transversely oval,
0.014 mm
in transverse width.
Remarks.
This species is so far known only from the
type
locality, which yielded three fertile colonies. Compared to the
type
species of
Plagioecia
, this new species has smaller zooids with more distantly spaced apertures.