Deep Water Polymastiidae (Porifera, Polymastiida) from the South West Pacific Author Ekins, Merrick Queensland Museum, PO Box 3300, South Brisbane 4101, Brisbane, Queensland, Australia & School of Biological Sciences, University of Queensland, St Lucia, Queensland, 4072 Australia & Griffith Institute for Drug Discovery, Griffith University, Brisbane 4111, Queensland, Australia Author Erpenbeck, Dirk GeoBio-Center, Ludwig-Maximilians-Universität M ¸ nchen, Richard-Wagner-Strasse 10, 80333 Munich, Germany & Dept. of Earth and Environmental Sciences Ludwig-Maximilians-Universität M ¸ nchen, Richard-Wagner-Strasse 10, 80333 Munich, Germany Author Wörheide, Gert 0000-0002-6380-7421 GeoBio-Center, Ludwig-Maximilians-Universität M ¸ nchen, Richard-Wagner-Strasse 10, 80333 Munich, Germany & Dept. of Earth and Environmental Sciences Ludwig-Maximilians-Universität M ¸ nchen, Richard-Wagner-Strasse 10, 80333 Munich, Germany & SNSB - Bayerische Staatssammlung f ¸ r Paläontologie und Geologie, Richard-Wagner-Str. 10, 80333 M ¸ nchen, Germany woerheide @ lmu. de; https: // orcid. org / 0000 - 0002 - 6380 - 7421 woerheide@lmu.de Author Hooper, John N. A. Queensland Museum, PO Box 3300, South Brisbane 4101, Brisbane, Queensland, Australia & Griffith Institute for Drug Discovery, Griffith University, Brisbane 4111, Queensland, Australia text Zootaxa 2023 2023-11-08 5369 1 57 88 https://www.mapress.com/zt/article/download/zootaxa.5369.1.3/52229 journal article 10.11646/zootaxa.5369.1.3 1175-5326 10146837 F906AFDC-DA4E-4ADB-9835-BC4B7692F1FD Radiella sclera sp. nov. Ekins, Erpenbeck & Hooper urn:lsid:zoobank.org:act: 735298BB-B9BA-4A42-A972-12779E97830A Figures 1 & 5 , Table 3 Type material: Holotype QM G316333 , Lord Howe Plateau , Pacific Ocean Seamounts , Australia , -34.2315 , 162.6765 , 515–700 m , Sherman Sled , Coll. NORFANZ expedition on RV Tangaroa , 85-014, MF336, 26/V/2003 . Etymology: named for its texture, sclera L., hard f. Diagnosis: A very hard Radiella species anchored to rock by choanosomal tracts of tylostyle forming root like processes. The sponge lacks a fringe and a purely radial skeleton, having instead a multilayered complex choanosomal skeleton. FIGURE 5. Radiella sclera sp. nov. Holotype QM G316333. A–B. Upper and lower surfaces of the preserved holotype. C–D. Light micrographs of sections through the radial thin ectosomal skeleton (C), and bouquets of tylostyles in the ectosome (D). E. Principal tylostyle. F. Enlarged view of principal tylostyle. G. Intermediate tylostyle. H. Enlarged view of intermediate tylostyle. I. Small tylostyle. TABLE 3. Comparison of characters between the different species of Radiella and Spinularia . (T=Tylostyles, S=Subtylostyles).

Distribution	Depth (m)	Substrate	Specimen shape upper/ lower	Specimen width (mm)	Specimen height (mm)	Fringe width (mm)	Number of papillae	Ectosomal Skeleton	Choanosomal skeleton	Basal Skeleton	Fringe Styles (μm)	Principal Styles (μm)	Ectosomal Styles (μm)	Intermediate Styles (μm)	Raphides (μm)
Radiella alvea ( Hansen, 1885 ) :9	Atlantic, Arctic	2354	Clay	Beehive, Convex	?	?	?	1	Radial	Radial tracts	Envelope	?	?	?	?	Absent
Radiella antarctica Plotkin & Janussen, 2008:111-116 , Figs. 7-9.	Antarctica	2086– 4800	Pebbles	Convex	9–30	2–8	0.7	1	Bouquets and palisade	Radial Tracts	Envelope + Thatch	T 2500– 5600	S 957– 2686	S 125– 636–1271	-	Absent
Radiella conica ( Hansen, 1885 ) :10 Radiella endeavourensis	Atlantic, Arctic	2354	Shell	Flattened cone	?	?	?	1?	Radial	Confused	Absent	?	?	?	?	Absent
Austin, Ott, Reiswig, Romagosa & McDaniel, 2014:33-36 , Fig. 11	NE Pacific	2500	?	?	11	6	0.5–0.9	3+	Twin layered	Radial + Confused	Envelope + Thatch	S 2600	S 1070– 2230	T 360–730	-	Absent
Radiella irregularis ( Ridley & Dendy, 1886 ) :489; Ridley & Dendy, 1887:220-221	Chile	3950	Blue Mud	Concave/ convex	17	8.5	1	2+	Radial	Confused	Thatch	?	>500	<1000	500	Absent
Radiella nidula sp. nov. Present study	Australia	999– 1761	Mud	Concave/ convex	16	4	4	1-6	Palisade	Radial + Confused	Radial	1990– 4070 × 14–47	T 780– 1510 × 9–24	T 780–1510 × 5–21	T 220–660 × 5–21	Absent
Radiella pumix sp. nov. Present study	Australia	2587– 2562	Mud	Convex	6–8	1	-	1	Discrete 3D bouquets	Confused	Thatch	–	T 640– 2270 × 7–19	T 100–300 × 6–13	T 360–660 × 3–15	Absent
Radiella sclera sp. nov. Present study	Lord Howe Plateau SW Pacific	515– 700	Rocks?	Convex	24	5	-	?0	Palisade	Radial + Confused	Thatch	–	T 910– 1450 × 12–30	T 250–550 × 5–15	T 560–980 × 8–24	Absent
Radiella sol Schmidt, 1870:48 Pl. IV , Fig. 6	Cuba	1116	?	Convex	20	?	?	15	Palisade and tangential	Radial Tracts	Thatch	S>5000	S 2280– 5400	290–390	490–618	Absent

......continued on the next page TABLE 3. (Continued)

Distribution	Depth (m)	Substrate	Specimen shape upper/ lower	Specimen width (mm)	Specimen height (mm)	Fringe width (mm)	Number of papillae	Ectosomal Skeleton	Choanosomal skeleton	Basal Skeleton	Fringe Styles (μm)	Principal Styles (μm)	Ectosomal Styles (μm)	Intermediate Styles (μm)	Raphides (μm)
Radiella straticulata ( Wilson, 1925 ) : 347-350, Pl. 38, Fig.7, Pl. 48, Fig. 1.	Philippines	2021	?	Concave/ convex	9–20	?	?	6-8	Triple layered	Radial Tracts	Triple layered, Tangential	6000– 10000 × 24	1600– 4000 × 17–24	T 600–2000 × 16	T 300–900 × 8–16	Absent
Spinularia australis Lévi, 1993: 25 Fig. 7A, Pl. II, Fig. 8.	New Caledonia	1900	Pumice	Convex	3–8	1–3	?	1	Radial	Radial	Radial	T 1800– 2500 × 20	T 1100– 1600 × 15–20	T 300–500 × 8–10	T 600–800 × 12	170–180
Spinularia flagellata sp. nov. Present study	Australia	750– 1147	Mud	Concave/ convex	15	7	2	1	Palisade	Radial tracts	Radial	T 1510– 3500 × 15–50	T 700– 2430 × 7–27	T 210–980 × 10–25	-	80–160
Spinularia njordi Plotkin, Gerasimova & Rapp, 2018:1312- 1314 , Fig. 27	Arctic	1997– 2457	Gravel	Convex/ convex	16–24	8	3	1	Palisade and Tangential	Tracts	Absent	-	S/T 1116– 2579	T 201–422	S/T 422–1128	Absent
Spinularia sarsii ( Ridley & Dendy, 1886 ) : 488-489; ( Ridley & Dendy, 1887:218-220 Spinularia	Atlantic, Arctic	10– 225– 2630	Concave/ convex	10	6	1.5–4	1-4	?	Confused	Thatch	T/S 5090– 6030	T 871– 2900	S 250–600	S 152–290	Absent
spinularia ( Bowerbank, 1866 ) :94-96	Arctic	30– 1001	Stone	Convex	23	12	?	11	Palisade, two layers	Tracts	?	-	T 404– 1355	T 161–373	-	65–85

Morphology: The sponge is a hard incompressible, cream coloured low flat to convex cushion 23.5 mm in dimeter and 4.53 mm in height ( Fig. 5 A ). The sponge was presumably attached to some hard substrate (possibly sunken pumice), as stain marks are apparent on the lower surface and the base of spicule bouquets emerge from the body to form root-like processes ( Fig. 5 B ). There were no apparent papillae or oscular structures present on the upper surface. In cross section the choanosome is cream in colour, whilst the dense spicule ectosome is colourless ( Fig. 5 B ). The surface of the ectosome is cream in colour, but this is most likely due to sediment. Skeleton: The ectosomal skeleton is a dense palisade of principal styles arising from bouquets formed in the choanosome ( Fig. 5 D ). The choanosome is a confused array of the two smaller sizes of tylostyles, often in small bundles of the intermediate sized tylostyles ( Fig. 5 C ). Bouquets of the principal styles originate exterior to the underside of the sponge body where they function as root-like anchoring processes. These bouquets radiate up through the choanosome all the way up to the ectosome ( Fig. 5 C, D ). The principal tylostyles that form the bouquets on the upper ectosome are also the same spicules that form the radial thin lower ectosomal skeleton ( Fig. 5 C ), which ascends on the periphery to form another bouquet ( Fig. 5 D ). The small and intermediate tylostyles are present throughout the choanosome. Spicules: The megascleres are composed of three overlapping sizes of tylostyles, which all represent a gradation. As the tylostyles increase in length, they also proportionally decrease in width. The two smaller sizes of tylostyles are much thicker towards the point, whilst the largest tylostyles are slightly thicker towards the head. Principal tylostyles are 913–(1140)–1450 × 12.0–(18.8)–30.0 μm, n=46 ( Fig. 5 E, F ). The intermediate tylostyles are 557– (744)–980 × 8.4–(13.9)–21.4 μm, n=34 ( Fig. 5 G, H ), whilst the small tylostyles are 245–(416)–554 × 5.4–(11.0)– 15.7 μm, n=47 ( Fig 5 I ). Distribution: Known only from seamounts in the Lord Howe Plateau, bathyl depths. Ecology: Attached to a hard substrate, most likely rocks Molecular data: no unambiguous 28S-C region barcode could be generated from this species. Remarks: This new species lacks the very large fringing styles that are normally obvious in species of the genus Radiella . This species differs from S. australis Lévi, 1993 in being much larger, lighter in colour, with a harder, denser and incompressible texture. Furthermore, our new species lacks the purely radial skeleton found in S. australis , but has a multilayered complex choanosomal skeleton instead. It also lacks the large fringe tylostyles as well as the raphides found in the New Caledonian specimens.