Adeonellopsis minor 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 minor

description: Adeonellopsis minor n. sp.
(Figs 3H, 15, 17B; Tables 1, 2)
Etymology. Latin minor, smaller, the comparative form of parvus, alluding to the small colony and branch sizes.
Material examined. Holotype: Australian Museum U. 5798, from NIWA Stn U 207, 34.1850° S, 151.4333° E, 198 m, New South Wales shelf, Tasman Sea. Paratypes: Australian Museum U. 5799, same data as holotype; NIWA 146152, same data as holotype.
Diagnosis. Branches slender, mostly 1 mm wide. Autozooids averaging 607 μm long, 270 μm wide. Autozooi-dal spiramen circular–oval with 3–4 pores. Small suboral avicularia mostly paired and directed distally. One other such avicularium at proximal end of zooid in ephebic zooids. Subvicarious avicularia on branch margins. Putative gonozooids slightly larger than autozooids, with larger orifices and spiramina, the latter with 6 pores.
Description. Mature intact colony not seen. Isolated branches slender, 0.8–1.1 mm wide, mostly 1 mm, more or less bifurcating in more than one plane, twiggy. Colour of dried colony pale creamy-brown.
Autozooids arranged in quincunx; 4–5 longitudinal series across width of branch. Neanic zooids roundly elongate-subhexagonal to elongate-rectangular. Interzooidal boundaries indicated by thin lines of calcification in interzooidal furrows, which are bordered by 13–17 small areolar pores in a series around the entire zooidal margin. Autozooids averaging 607 μm long, 270 μm wide in 4–5 series across the branch (Fig. 15A).
Autozooidal peristomial orifice suborbicular to more or less transversely and roundly D-shaped; the inner proximal marginal with sparse denticulation (Fig. 15C) or this lacking. Spiramen (Fig. 15D) circular–oval, averaging 79 μm long, 63 μm wide, with 3–4 spiraminal pores, each with mostly very short spokes that do not touch; becoming relatively quickly sunken.
Suboral avicularia (Fig. 15B, G) small, squat, mostly paired, generally off-centre if single and an adjacent areola pore (source of avicularium) in place of second suboral avicularium; rostrum mostly directed distally, sometimes transversely or obliquely, the tip closed (lacking channel). Common rostral-opesial foramen lacking denticulation of margin; cryptocyst smooth.
Subvicarious avicularia (Fig. 15E, F) on branch margins; like adventitious zooidal avicularia but rostral-opesial portion more elongate, the rostral tip closed, opesial cryptocyst smooth; articular pivot ridges short, thin, curved.
Putative gonozooids (Figs 15B; 17B) slightly larger than autozooids, with larger orifices and spiramina, the latter with 6 pores.
Ancestrula and early astogeny not seen.
Remarks. Adeonellopsis minor n. sp. closely resembles Adeonellopsis gracilis n. sp. in its very slender branches but differs from it in having a larger zooid size and rounded spiramina. Adeonellopsis minor n. sp. also superficially closely resembles A. gemina n. sp., but most obviously differs from it in having thinner branches, larger autozooids and smaller dimensions for the subvicarious marginal avicularia. Adeonellopsis minor n. sp. differs from A. yarraensis in having the autozooidal spiramen close to the orifice, such that the orifice, suboral avicularia and spiramen can be partly immersed in a common furrow of secondary calcification in highly ephebic zooids.
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 page 322, DOI: 10.11646/zootaxa.4895.3.1, http://zenodo.org/record/4326650