Adeonellopsis macewindui Liow & Gordon 2020, n. sp.

Adeonellopsis macewindui n. sp.

(Figs 3 A–B, 4–7; Tables 1, 2)

Adeonellopsis morphotype E?: Lidgard & Buckley 1994: p. 104.

Adeonellopsis sp. Smith et al. 2001: p. 202, fig. 1; Smith & Key 2004: p. 124, fig. 1; Wejnert & Smith 2008: p. 391, fig. 2; Smith 2009: p. 479, fig. 4(a); Smith & Garden 2013: p. 329, 332.

Adeonellopsis sp. 4: Orr et al. 2019: p. 3, table 1, fig. (https://doi.org/10.1186/s12862-019-1563-4).

Etymology. Named for the fictional character Mace Windu in the Star Wars franchise; he uniquely wielded a purple-bladed light sabre. The name alludes to the new purplish-bladed Adeonellopsis species while indirectly acknowledging the ‘Black Lives Matter’ movement through African-American actor Samuel L. Jackson who played the role of Mace Windu.

Material examined. Holotype: NIWA 146070, NIWA Stn O840, 45.3152° S, 167.0073° E, Doubtful Sound, Fiordland, 35 m. Paratype: NIWA 101582, Stn Z15948, 45.3488° S, 167.0557° E, Doubtful Sound, Fiordland, 5 m. Other : NIWA 74689, Stn TAN1108/108; NIWA 74801, Stn TAN1108/117; NIWA 74940, Stn TAN1108/138; NIWA 92710, Stn TQI1201/25; NIWA 97307, Stn E820; NIWA 146063, Stn D131; NIWA 146064, Stn D132; NIWA 146065, Stn D144; NIWA 146066, Stn O840; NIWA 146067, Stn O841; NIWA 146068, Stn W74; NIWA 146069, Stn Z7341; NIWA 146087, Stn K778; NIWA 146092, Stn D133; NIWA 146098, Stn P26.

Diagnosis. Branches flattened, mostly 4 mm wide. Autozooids averaging 568 μm long, 279 μm wide. Autozo-oidal spiramen mostly with 4–7 pores. Moderately large suboral adventitious avicularium on almost every zooid, including gonozooids. Small adventitious avicularium occurring proximally on zooid, less commonly also distal or lateral to orifice, and many budded independently by frontal budding on colony margins and older colony parts. Large vicarious avicularia at sparse intervals along colony margins. Gonozooids large, with dimorphic orifices; spiramen like that of autozooids but larger, with 12–17 pores; 0–4 small accessory adventitious avicularia.

Description. Colony erect, rigid, achieving a dense thicket up to c. 30 cm in diameter and 15–30 cm high, of branching bilamellar flat or slightly curving branches; clusters of adjacent branches often having similar growth direction, otherwise branching in various directions (alternately to left or right or bifurcating) with many branch fusions. Colour in life dark purplish-brown with cream-coloured branch tips, fading to purple, lavender or greyish in older moribund colonies; creamy-brown when dry. Branch widths varying with age of colony, mostly 4 mm wide between bifurcations, wider just proximal to bifurcations. Autozooids arranged in quincunx; 6–14 longitudinal se-ries according to branch width (Fig. 5A).

Neanic autozooids (Fig. 5B, C) 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 18–26 areolar pores in single series around entire zooidal margin; a few additional areolar pores closer to orifice and suboral avicularium; marginal areolae sometimes merging as zooids acquire additional calcification. Average zooid length and width 568 μm and 279 μm, respectively.

Autozooidal peristomial orifice transversely D-shaped, becoming sunken within deepening peristome as zooids age. Interior view of orifice shows a pair of blunt condyles, one in each proximolateral corner (Fig. 6C). Multiporous spiramen (Fig. 6D) in frontal depression, more or less central in zooid but position can vary; averaging 95 μm long, 63 μm wide; spiraminal pores mostly 4–7, varying a little in size and shape but typically circular–oval, each with 2–8 spokes that mostly do not touch. Spiramen becoming deeply sunken and somewhat concealed as frontal shield thickens.

Adventitious avicularia (Figs 5B; 7B, C, E) varying in size, position and orientation but all having same form, i.e. elongate-triangular rostrum with open-channelled acute tip and smooth raised (gymnocystal) margins, common rostral-opesial foramen, semicircular opesial margin, granular crescentic cryptocyst and no pivot bar; short curved pivot ridges at rostral-opesial transition; granules at edge of avicularian opesia create impression of fine denticulation. Suboral avicularium initially moderately large, the rostrum elevated obliquely frontalwards, directed distally or, more often, distolaterally, the tip reaching just past corner of orifice or overlapping it medially, or not quite reaching orifice. As zooids age, individual suboral avicularian cystids frontally bud additional avicularia, by reparative budding and/or to keep pace with secondary calcification, becoming progressively smaller (Fig. 7F), rarely with an adjacent such avicularium to form a pair. A small adventitious avicularium commonly forming in a mid-proximal position as zooids age, directed distolaterally; a similar avicularium less common distal or lateral to zooidal orifice. In ephebic zooids, suboral avicularium and spiramen sunken in common depression, with spiramen at lower level.

Vicarious avicularia (Figs 5C; 6B; 7A, D) at variable intervals along or near branch margins, less often frontally near margin, their cystids each about the length of an autozooid or larger and typically projecting from surface, especially the distal part. Opesial cryptocyst smooth, narrowing midproximally. Budding of a new vicarious avicularian cystid within the parent cystid can take place.

Gonozooids (Figs 5A, C; 6A) enlarged, showing vestigial ooecia during ontogeny, averaging 705 μm long, 436 μm wide, occurring generally in small clusters a few zooid-lengths proximal of a branch bifurcation or adjacent to a branch margin. Peristomial orifice larger and proportionately much wider (mean 197 μm) than autozooidal orifice, with very large spiramen (Fig. 6A) of 12–17 pores, each pore having 2–5 radii that tend to fuse. A single suboral avicularium, proportionately small, immediately distal to spiramen and not reaching orifice; 0–4 additional small adventitious avicularia on ephebic gonozooids.

Ancestrula and early astogeny not seen.

Remarks. Adeonellopsis macewindui n. sp. forms the largest and most robust colonies of any of the seven new species described herein. Of the Australian species listed by P.E. Bock on the Bryozoa Home Page (some illustrated), Adeonellopsis sulcata (Milne Edwards, 1836) has autozooids with similar suboral avicularia but differs principally in colony form (foliaceous laminae instead of staghorn branches) and spiraminal-pore number (8–11 in autozooids, 17–20 in gonozooids vs 4–8 and 12–17 pores respectively in A. macewindui n. sp.). Two others of the new species described herein have similar moderate-sized suboral avicularia, but Adeonellopsis tasmanensis n. sp. differs from A. macewindui n. sp. in having 18–25 spiraminal pores in its gonozooid and more accessory adventitious avicularia per zooid and gonozooid, and Adeonellopsis periculosa n. sp. has only 2–5 spiraminal pores in autozooids and 4–6 such pores in gonozooids.

Material of A. macewindui n. sp. from the Snares Shelf was sequenced as part of a molecular-phylogenetic study of Adeonidae (Orr et al. 2019). It formed part of a clade of Adeonellopsis species from Western Australia and New Zealand, collectively sister to Adeona in the molecular tree.

Distribution. Norfolk Ridge (Australian EEZ): Norfolk Island shelf, 130 m. New Zealand: Greater Cook Strait (South Taranaki Bight), Otago Shelf, Fiordland (Doubtful Sound, Thompson Sound), Puysegur Bank, Snares Shelf, 5– 220 m.