New species of Adeonellopsis (Bryozoa: Adeonidae) from southern Zealandia and the western Tasman Sea
Author
Liow, Lee Hsiang
0000-0002-3732-6069
Natural History Museum and Centre for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway. l. h. liow @ ibv. uio. no; https: // orcid. org / 0000 - 0002 - 3732 - 6069
l.h.liow@ibv.uio.no
Author
Gordon, Dennis P.
National Institute of Water & Atmospheric Research, Private Bag 14901, Kilbirnie, Wellington 6022, New Zealand. dennis. gordon @ niwa. co. nz; http: // orcid. org / 0000 - 0001 - 9398 - 996 X
dennis.gordon@niwa.co.nz
text
Zootaxa
2020
2020-12-16
4895
3
301
331
journal article
9252
10.11646/zootaxa.4895.3.1
a5e5d5ad-9d52-48cd-9bf9-ca28a2a7af4b
1175-5326
4326650
C6F85190-D79E-429E-9B5B-FD0E54AE96BC
Adeonellopsis wassi
n. sp.
(
Figs 3E
,
9
C–D, 10;
Tables 1
,
2
)
Etymology.
Honorific for retired bryozoologist Dr Robin E. Wass to acknowledge his contributions to knowledge of Australian Paleozoic and Recent bryozoans.
Material examined.
Holotype
:
Australian Museum U.
5794, from
NIWA
Stn U
207,
34.1850° S
,
151.4333° E
,
198 m
,
New South Wales
shelf,
Tasman
Sea
.
Paratypes
:
Australian Museum U.
5795, same data as holotype
;
NIWA 144898
, same data as holotype
.
Diagnosis.
Branches flattened, mostly
3 mm
wide. Autozooids averaging 931 μm long, 423 μm wide. Auto-zooidal spiramen mostly with 6–7 pores. Suboral avicularia 1–3, moderate-sized; no additional such avicularia in ephebic zooids. Large vicarious avicularia absent; rather, cystids of marginal avicularia subvicarious with functional rostral-opesial component same size as autozooidal suboral avicularia. Putative gonozooid slightly larger than autozooids with larger spiramen of 14 pores. Adventitious avicularia as for autozooids.
FIGURE 10.
Adeonellopsis wassi
n. sp.
(NIWA 144898): A. Autozooids and a possible gonozooid. B. Autozooidal peristomial orifice showing denticulation of inner proximal rim. C. Close-up of suboral autozooidal avicularia; note the pore on the right that may later produce a third avicularium. D. Marginal subvicarious avicularian cystids with small rostral-opesial area. E. Autozooidal spiramen. Scalebars: A, 500 μm; B, C, E, 100 μm; D, 300 μm.
Description.
Colony erect, rigid, maximum size not known; longest available branch fragment
4.2 cm
, lateral branching sparse, with distance between bifurcations variable, sometimes quite long; branching in same plane. Colour in life unknown; dried fragments pale creamy-brown. Branch widths varying with age of colony, 2.0–
3.8 mm
, mostly
3 mm
between bifurcations, wider just proximal to bifurcations. Autozooids arranged in quincunx; 6–10 longitudinal series according to branch width (
Fig. 9C
).
Neanic autozooids (
Fig. 9D
) more or less rounded-subhexagonal, becoming more elongate-rectangular with ageing and secondary calcification. Interzooidal boundaries indicated by thin lines of calcification in interzooidal furrows, bordered by 16–26 areolar pores in single series around entire zooidal margin. Zooids relatively large, mean zooid length and width 931 μm and 423 μm, respectively.
Autozooidal peristomial orifice suborbicular to a transversely rounded D-shape. Denticulation (
Fig. 10B
) of inner peristomial margin well developed, sparse or absent. Multiporous spiramen in frontal depression (
Fig. 10A, E
) circular–oval, more or less central; averaging 122 μm long, 96 μm wide; spiraminal pores 5–10, mostly 6–7, each with 4–7 short spokes that do not touch.
Adventitious avicularia (
Figs 9D
;
10A, C
) suboral only, typically 1–2 but increasing to
3 in
ephebic zooids; one is placed medially, pointing mostly distally, with a second to one side of it pointing transversely or obliquely toward it; an areolar pore on the opposite side of the median one can later develop into a third such avicularium, converging towards its partners so that the tips of all three somewhat converge. All have the typical form, with a narrow openchannelled rostral tip, smooth raised (gymnocystal) margins, common rostral-opesial foramen with slight denticulation and mostly smooth cryptocyst; no pivot bar but short curved pivot ridges at rostral-opesial transition.
Large vicarious avicularia absent; instead, subvicarious avicularian cystids occur on branch margins (
Fig. 10D
). The functional rostral-opesial (gymnocystal) part of the avicularium has the same size and form as the suboral avicularia of autozooids, the rostral tips frontally elevated.
Only one putative gonozooid seen (
Fig. 10A
), 1104 μm long, 511 μm wide, occurring four zooid lengths be-low a bifurcation. Gonozooid peristomial orifice 147 μm wide, the spiramen larger than autozooids, with 14 pores, each with 4–7 short spokes that do not touch unless pore laterally constricted. Two suboral avicularia like those in autozooids.
Ancestrula and early astogeny not seen.
Remarks.
Compared to the two new species described above,
Adeonellopsis wassi
n. sp.
has relatively smaller suboral avicularia, reminiscent of those in
Adeonellopsis gemina
n. sp.
and
Adeonellopsis minor
n. sp.
. Colony form in these latter two species differs markedly, however, being smaller with thinner branches. Overall,
A. wassi
has the largest zooids of any of the new species described herein. It also has only subvicarious avicularia on its branch margins.
Distribution.
Australia
:
New South Wales
shelf,
198 m
.