Adeonellopsis wassi Liow & Gordon 2020, n. sp.
Creators: name: Liow, Lee Hsiang
name: Gordon, Dennis P.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Bryozoa
Gymnolaemata
Cheilostomatida
Adeonidae
Adeonellopsis
Adeonellopsis wassi

description: 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.
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.
description: Published as part of Liow, Lee Hsiang & Gordon, Dennis P., 2020, New species of Adeonellopsis (Bryozoa: Adeonidae) from southern Zealandia and the western Tasman Sea, pp. 301-331 in Zootaxa 4895 (3) on pages 315-316, DOI: 10.11646/zootaxa.4895.3.1, http://zenodo.org/record/4326650