Skolosachlys nidus Ekins, Erpenbeck & Hooper, 2023

Ekins, Merrick, Erpenbeck, Dirk, Debitus, Cécile, Petek, Sylvain, Mai, Tepoerau, Wörheide, Gert & Hooper, John N. A., 2023, Revision of the genus Fascaplysinopsis, the type species Fascaplysinopsis reticulata (Hentschel, 1912) (Porifera, Dictyoceratida, Thorectidae) and descriptions of two new genera and seven new species, Zootaxa 5346 (3), pp. 201-241 : 223-226

Skolosachlys nidus Ekins, Erpenbeck & Hooper sp. nov.

Figures 10 , 12

urn:lsid:zoobank.org:act:7DE686EF-3D3C-436F-BBCC-B80225B5F34F

Material examined.

Holotype: QM G320018, Between Barren and Child Islands , Keppel Islands , Queensland, Australia, 23.1592°S, 151.07056°E, 17.6 m, walls and large rocks, SCUBA, Coll. J.N.A. Hooper, S.D. Cook, S. List-Armitage, M. Richer de Forges, A. Crowther & C. Ireland, 4/XI/2002.

Paratypes: QM G313004, Dixon Reef, Malekula Island, Vanuatu, 16.3565°S, 167.3651°E, 21.7 m, coral reef, SCUBA, Coll. J.N.A. Hooper, 21/ V /1997; QM G307325 Fifth Point, Heron Island, Capricorn-Bunker Group, Queensland, Australia, 23.4189°S, 151.985°E, 19 m, outer reef slope, gullies, overhangs, ledges, SCUBA, Coll. J.N.A. Hooper, S.D. Cook, J.A. Kennedy & P.A. Tomkins, 8/VIII/1996; QM G321773, Rock Cod Shoal, Great Barrier Reef, Queensland, Australia, 23.6770°S, 151.6183°E, 5–14 m, coral reef, SCUBA, Coll. M. Ekins, S.D. Cook, A. Crowther, G. Carini, C. Strickland, P. Sutcliffe, & M. Mitchell, 11/XI/2004.

Other material. QM G303844, Triangle Reef, Hook Reef, Great Barrier Reef, Queensland, Australia, 19.81722°S, 149.11694°E, 21 m, coral reef 6–9 m depth, gulleys, sharp drop-off to 22m depth, caves, corals and rubble at base, SCUBA, Coll. J.N.A. Hooper & L.J. Hobbs, 8/XII/1993; QM G305400, Gannet Cay, Great Barrier Reef, Queensland, Australia, 21.98472°S, 152.46833°E, 24 m, fore-reef slope, bommies, abundant coral, SCUBA, Coll. J.N.A. Hooper, S.D. Cook, J.A. Kennedy, & P.A. Tomkins, 23/VII/1995; QM G305704, Bacci Cay, Riversong Cays, Great Barrier Reef, Queensland, Australia, 21.63444°S, 152.38361°E, 28 m, fore reef, sheer slope, terraces at 15, 22, 28 m depths, SCUBA, Coll. J.N.A. Hooper, S.D. Cook, J.A. Kennedy, & P.A. Tomkins, 29/VII/1995; QM G306798, Malila Island, Espiritu Santo, Vanuatu, 15.35139°S, 167.20056°E, 31.3 m, outer reef slope, abundant coral, Halimeda at base, SCUBA, Coll. J.N.A. Hooper, 24/ VI /1996; QM G306970, Cook Reef, Vanuatu, 17.03472°S, 168.25167°E, 22 m, coral reefs, SCUBA, Coll. ORSTOM Noumea, 10/ VI /1996; QM G307225, Sykes Reef, Great Barrier Reef, Queensland, Australia, 23.41889°S, 152.05056°E, 25 m, patch reef to 30 m, gentle slope, sand gullies, SCUBA, Coll. J.N.A. Hooper, S.D. Cook, J.A. Kennedy, & P.A. Tomkins, 7/VIII/1996; QM G318318, inside Hard Line Reefs, Great Barrier Reef, Queensland, Australia, 20.83550°S, 151.16234°E, 23.6 m, sloping reef with outcrops, SCUBA, Coll. S.D. Cook, J.A. Kennedy, G. Wörheide, & W. Delaney, 17/III/2000; QM G320089, Outer Rock, Keppel Islands, Queensland, Australia, 23.06639°S, 150.95278°E, 15.8 m, shallow fringing reef, bommies deeper, SCUBA, Coll. J.N.A. Hooper, S.D. Cook, S. List-Armitage, M. Richer de Forges, A. Crowther, & H. Ireland, 5/XI/2002; QM G310626, Scawfell Island, Northern End Of Refuge Bay, Queensland, Australia, 20.85°S, 149.6083°E, 20 m, Coll. Australian Institute of Marine Science & National Cancer Institute, Q66C 1776- V, 9/XI/1988; QM G314744, Little Lindeman Island, Queensland, Australia, 20.42206°S, 149.042664°E, 22 m, small coral bommies, very silty, many soft corals, SCUBA, Coll. S.D. Cook, J.A. Kennedy, C.L. Adams, G. Wörheide, & D. Edson, 2/ VI /1999; QM G314871, Pinnacle Point, Hook Island, Great Barrier Reef, Queensland, Australia, 20.06058°S, 148.96106°E, 18 m, fringing reef and coral bommies, SCUBA, Coll. S.D. Cook, J.A. Kennedy, C.L. Adams, G. Wörheide, & D. Edson, 3/ VI /1999; QM G314891, Cateran Bay, Border Island, Great Barrier Reef, Queensland, Australia, 20.15258°S, 149.04233°E, 30m, fringing coral reef, SCUBA, Coll. S.D. Cook, J.A. Kennedy, C.L. Adams, G. Wörheide, & D. Edson, 4/ VI /1999; QM G314893, same collection details as QM G314891; QM G315271, Round Reef, Great Barrier Reef, Queensland, Australia, 19.960733°S, 149.62126°E, 20 m, back reef, SCUBA, Coll. S.D. Cook, J.A. Kennedy, C.L. Adams, G. Wörheide, & D. Edson, 6/ VI /1999; QM G317573, Reef 21–490, Swain Reefs, Great Barrier Reef, Queensland, Australia, 21.61400°S, 152.34705°E, 20 m, back reef, 100% coral cover, flat bottom with occasional small bommies to 1.5m high, SCUBA, Coll. J.N.A. Hooper, S.D. Cook, J.A. Kennedy, D. Edson, & G. Wörheide, 8/II/2001; QM G317850, Mackerel Reef, Swain Reefs, Great Barrier Reef, Queensland, Australia, 21.83610°S, 151.97195°E, 30 m, back reef bommies, SCUBA, Coll. J.N.A. Hooper, S.D. Cook, J.A. Kennedy, D. Edson, & G. Wörheide, 12/II/2001; QM G318141, un-named reef, Pompey Group, Great Barrier Reef, Queensland, Australia, 21.16217°S, 151.35201°E, 27 m, coral reef, SCUBA, Coll. S.D. Cook, J.A. Kennedy, G. Wörheide, & W. Delaney, 14/III/2000; QM G318207, Reef 21-097, inside Hard Line Reefs, Great Barrier Reef, Queensland, Australia, 21.04017°S, 151.48084°E, 27 m, steep back reef sloping to sand, SCUBA, Coll. S.D. Cook, J.A. Kennedy, G. Wörheide, & W. Delaney, 15/III/2000; QM G329599, North side Aore I, off Luganville on southern side of Segond Channel, Espiritu Santo, Vanuatu, 15.53138333°S, 167.1937167°E, 16 m, steep sand slope, bommies, abundant sponges, patch reef at top, SCUBA, UUVAN082027, Coll. J.N.A. Hooper, 29/X/2008.

Etymology. nidus L. n., nest.

Distribution. This species is presently known only from Queensland, Australia and Malekula and Espiritu Santo, Vanuatu ( Fig. 10 ).

Description:

Growth form: Massive vasiform ( Fig. 12 A–B ). Often with epibionts growing over the surface. The holotype in the collection is currently 10–12 cm wide, by 6 cm high and 3.5 cm thick. Before collection it was at least 15 cm high. The sponges can easily obtain vases of up to 40 cm in height.

Colour: The sponge is brown in colour, often covered with epibionts. Internally the sponge has a greenish yellow interior, with orange fibres ( Fig. 12 D ). In 70% ethanol, the internal colour changes from a yellow to brown and sometimes grey.

Oscules: The 3–5 mm wide oscules are rare and scattered located on the outside of the vase, sometimes often in a sieve plate formation (e.g., QM G321773).

Texture: Harsh, compressible, firm and tough, but can be torn easily.

Surface: Sharp conules and ridges concentrated on the exterior of the vase giving the sponge a harsh exterior. The conules are 2–3 mm high, sometimes with a truncated finish as several fibres which have joined in bundles terminate close together, but usually it is just a single fibre ( Fig. 12 C ). The conules are connected to usually four sometimes three other conules with curvaceous ridges. The conules are 5–7 mm apart. On the exterior of the vase, the conules are between 2–3 mm in height, whilst inside the vase the conules are only 1–2 mm in height and lack the large ridges and valleys between them.

Ectosomal skeleton: Debris inside the sponge body are incorporated in the fibres. It often has large amounts of sand and spicules in the ectosomal layer. Fibres extend from choanosome to ectosomal surface producing conules

Choanosomal skeleton: The primary fibres are laminated and cored by detritus and a definite core in the centre third of the fibre ( Fig. 12 F ). The primary fibres are usually between 150 and 300 µm in thickness. The primary fibres are fascicular, forming bundles and have many crosslinking secondary fibres often forming ladder-like structures as they ascend to the surface. The secondary fibres are also laminated and are much less cored, also limited to the central third of the fibre. The secondary fibres range from 50 to 110 µm in diameter. There are rare aquiferous channels ~ 5mm in diameter. There is usually dark pigment in the choanosome.

Ecology. This species is associated with reefs, ranging from fore reefs to back reefs. It has been recovered from 14 to 31 m in depth, but generally deeper than Skolosachlys enlutea sp. nov. It is often covered with encrusting ascidians such as didemnids, sponges, algae, bryozoans and sandy silt. The cavernous interior of the sponge is sometimes colonised by barnacles.

DNA Barcodes.

28S: Holotype QM G320018 (LR699490).

ITS: Holotype QM G320018 (LR699341), Paratype QM G313004 (LR699340).

Remarks. Skolosachlys nidus sp. nov. differs from S. enlutea sp. nov., by its vase-shaped morphology, the brown colouration, the smaller conules, a less harsh appearance and the absence of the striated armouring. The skeleton in S. nidus , has fewer fasciculations of the primary fibres and has very reduced aquiferous channels, making the sponge much less compressible.

Figures

FIGURE 10. Distribution of Skolosachlys enlutea sp. nov. and Skolosachlys nidus sp. nov. Base map modified from freevectormaps.com.

FIGURE 12. Skolosachlys nidus sp. nov. A. Holotype QM G320018 underwater. B. Holotype QM G320018 fixed, showing the birds nest/vase morphology. C. Exterior face of the holotype QM G320018 fixed. D. Cross section of the holotype QM G320018 immediately after collection, showing infrequent aquiferous channels. E. Microscope section of the holotype QM G320018 showing only partial armouring and debris incorporated into the body of the sponge. F. Primary and secondary fibres of the holotype QM G320018, showing laminated cored fibres.