Porifera: Demospongiae: Axinellida: Raspailiidae) from Deep Seamounts of the Western Pacific

Zootaxa 4410 (2): 379–386 ISSN 1175-5326 (print edition) http://www.mapress.com/j/zt/ Article ZOOTAXA Copyright © 2018 Magnolia Press ISSN 1175-5334 (online edition) https://doi.org/10.11646/zootaxa.4410.2.7 http://zoobank.org/urn:lsid:zoobank.org:pub:14C3B3C0-2DF9-4893-998F-23D96450C1FD

A new species of the sponge Raspailia (Raspaxilla) (Porifera: Demospongiae: Axinellida: Raspailiidae) from deep seamounts of the Western Pacific

MERRICK EKINS1,2,6, CÉCILE DEBITUS3, DIRK ERPENBECK4 & JOHN N.A. HOOPER1,5 1Queensland Museum, PO Box 3300, South Brisbane 4101, Brisbane, Queensland, Australia 2School of Biological Sciences, University of Queensland, St Lucia, Queensland, 4072 Australia 3LEMAR, IRD, CNRS, IFREMER, UBO, IUEM, rue Dumont d’Urville, 29280 Plouzané, France 4Dept. of Earth and Environmental Sciences and GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Straße 10, 80333 München, Germany 5Griffith Institute for Drug Discovery, Griffith University, Brisbane 4111, Queensland, Australia 6Corresponding Author. E-mail: [email protected]

Abstract

A new species of Raspailia (Raspaxilla) frondosa sp. nov. is described from the deep seamounts of the Norfolk and New Caledonia Ridges. The morphology of the species resembles that of a frond or a fern, and its unique highly compressed axial skeleton of interlaced spongin fibres without spicules in combination with a radial extra axial skeleton of a perpendicular palisade of spicules, differentiate it from all other species of the subgenus. This species is compared morphologically to all 18 other valid species described in Raspailia (Raspaxilla).

Key words: Raspailia, Raspaxilla, Aulospongus, Seamounts, Norfolk, New Caledonia, rhabdostyles

Introduction

The subgenus Raspailia (Raspaxilla) Topsent, 1913 was most recently reviewed by Hooper (2002), noting that it differed from typical Raspailia in having rhabdose echinating acanthostyles, and from other rhabdose raspailiids, notably Aulospongus Norman, 1878, in having echinating rhabdostyles geometrically very different from the usually longer choanosomal styles (the latter without any basal rhabd). There are currently 18 species recognised (Van Soest et al. 2017), distributed in the Southwest Pacific Ocean (New Caledonia, New Zealand, Torres Strait, northern Great Barrier Reef, Shoalhaven Bight New South Wales), Northwest Pacific Ocean (Japan, Micronesia), Northeast Indian Ocean (Northwest Shelf), Northeast Pacific Ocean (Mexico, Gulf of California), Southeast Pacific Ocean (Galapagos Islands), Northwest Atlantic (North Carolina), Southwest Atlantic Ocean (Malvinas/ Falkland Islands, Southeast Brazil), and Southwestern Indian Ocean subantarctic region (Prince Edward Islands). Bathymetric distributions of species range from the shallow subtidal waters to depths of over 400 metres. The present study describes a new species from deeper waters (200–310m depth) on the New Caledonian and Norfolk Ridges off New Caledonia, and compares it with other species in the subgenus Raspaxilla. The marine biota of this whole region is notably highly diverse (e.g. Payri & Richer de Forges 2007), and the deeper water (bathyal) sponges on these seamounts are otherwise well-documented (e.g. Lėvi & Lėvi 1983, Lévi 1993, Schlacher-Hoenlinger et al. 2005, Ekins et al. 2016).

Materials and methods

Collection of material. Sponges were collected by dredge from 200 to 310m on the top of deep seamounts off New Caledonia, on the Norfolk and New Caledonia Ridges. The sponges were preserved in ethanol after collection, and transferred to the Queensland Museum. All specimens were registered at the Queensland Museum (QM), and the holotype deposited in the Muséum National d’Histoire Naturelle (MNHN).

Accepted by N. de Voogd: 12 Feb. 2018; published: 17 Apr. 2018 379 Morphological analysis. Tissue preparations for light microscopy were made by cutting thin sections through the ectosome and choanosome with a scalpel. These sections were then cleared in a xylene-phenol saturated solution for 12 hours, dried, mounted on a microscope slide and fixed in Durcapan (Sigma Aldrich co., St. Louis, USA). Scanning Electron Microscope spicule preparations were made by dissolving the tissue in 12.5% sodium hypochlorite to remove the soft tissue, and neutralized in distilled water, rinsed twice in 70% ethanol and then finally in 98% ethanol and then air dried. SEM preparations were sputter coated in gold to improve resolution. Some of the SEM tissue preparations were simply dissected and then air dried before gold sputter coating. The scanning electron micrograph photos and measurements were made using a Hitachi TM-1000 SEM and plates assembled in Adobe Photoshop. The spicule size ranges are from those spicules that were the largest and smallest of all spicules from all three specimens. Molecular analysis. DNA was extracted with the DNEasy Mini Kit (Qiagen, Hilden) and with classical Phenol / Chloroform extractions (e.g. Sambrook 1989). PCR reactions for two independent markers (CO1, and C- region of 28S rDNA) were attempted following the procedures as described in Erpenbeck et al. 2016.

Results

Class Demospongiae Sollas, 1885

Subclass Heteroscleromorpha Cárdenas, Pérez & Boury-Esnault, 2012

Order Axinellida Lévi, 1953

Family Raspailiidae Hentschel, 1923

Genus Raspailia Nardo, 1833

Raspailiidae with a more-or-less compressed axial skeleton and a radial, plumose or simply reticulate extra-axial skeleton, with choanosomal spicules consisting of two, three or more different size classes (styles and/or oxeas), and echinating acanthostyles microcionid-like or secondarily modified (from Hooper et al. 2008).

Subgenus Raspaxilla Topsent, 1913

Synonymy: Raspaxilla Topsent, 1913: 616 (Type species: Raspaxilla phakellina Topsent, 1913: 617, by monotypy). Echinaxia Hallmann, 1916a: 543; 1917: 391 (Type species: Axinella frondula Whitelegge, 1907: 509, by original designation). Axinectya Hallmann, 1917: 393 (Type species: Axinella mariana Ridley & Dendy, 1886: 480, by original designation).

Definition. Raspailia with echinating rhabdostyles geometrically very different from the usually longer choanosomal styles (the latter without any basal rhabd); extra-axial styles forming a radial skeleton perpendicular to the axis; and well differentiated axial and extra-axial skeletons (the former compressed, the latter plumo- reticulate and/or radial) (from Hooper et al. 2008).

Raspailia (Raspaxilla) frondosa sp. nov. (Figs 1–4, Table 1)

Etymology. Latin for leafy, reflecting the gross morphology of the sponge resembling the frond of a fern. Material examined. Holotype: MNHN-IP-2015-1402 (fragment of the holotype QM G335124) Station DW3110, New Caledonia Ridge 23o1.35’ S 168o16.99’ E to 23o1.71’S 168o15.86E, 270–310 m, Coll. Cécile Debitus, 28.x.2008 (Samadi 2008). Paratypes: QM G335144 (same data as holotype). QM G318701 NORFOLK 1 Station DW1724, Norfolk

FIGURE 1. Fixed specimens of R. (R.) frondosa sp. nov., clockwise from the top left: paratype QM G335144; holotype MNHN-IP-2015-1402 (fragment QM G335124); paratype QM G318701.

Description. Growth form: A stalked foliaceous, flabellate to reniform sponge growing mainly in one plane but showing some undulations. The blades are between 55 and 65 mm high and 55 to 85 mm wide, with a maximum thickness of 3 mm at the base sloping to less than 1 mm at the apex. It has a circular stalked base with a diameter of 10 mm and small basal holdfast. Colour: Pale cream to orange on deck and beige to brown in ethanol. Texture: Firm and barely compressible, but easy to tear. Surface: Oscules are not visible, however on the surface the absence of parchment-like ectosome over the aquiferous channels resembles leaf veins (this is could also be due to friction or predation). Otherwise the surface is highly hispid and velvety from protruding long styles. Ectosomal skeleton: Membranous, parchment-like, without a specialised ‘raspailiid’ skeleton of spicule- bouquets, but with a thick palisade of subectosomal styles protruding through the ectosome up to 0.5–2 mm. Choanosomal skeleton: With well-differentiated axial and extra-axial skeletons. The axial skeleton is

A NEW SPECIES OF THE SPONGE RASPAILIA (RASPAXILLA) Zootaxa 4410 (2) © 2018 Magnolia Press · 381 compressed, lacking spicules, but with heavy interlaced spongin fibres forming a wide core up to 50% of the diameter of the skeleton. Long subectosomal styles and shorter choanosomal rhabdostyles have their bases embedded in the axial spongin skeleton, standing perpendicular to the axis forming a radial extra-axial skeleton, with the subectosomal styles protruding through the ectosome and the choanosomal rhabdostyles supporting the parchment-like ectosome on both dorsal and ventral surfaces of the sponge.

FIGURE 2. Spicules of the holotype R. (R.) frondosa sp. nov., MNHN-IP-2015-1402 (fragment QM G335124). A subectosomal style, B terminations of subectosomal style, C–G choanosomal rhabdostyles

FIGURE 3. An undigested cross section of the holotype of R. (R.) frondosa sp. nov., MNHN-IP-2015-1402 (fragment QM G335124), showing the choanosomal rhabdostyles supporting the fragile ectosome and the subectosomal styles penetrating the ectosome.

Megascleres (Table 1). There are only two categories of megascleres. Choanosomal rhabdostyles are very smooth, moderately thick, with a smooth non-tylote base, varying from slight to well-developed rhabds (97–469 x

TABLE 1. Spicule measurements of the type specimens of Raspailia (Raspaxilla) frondosa sp.nov. Specimen Choanosomal Choanosomal Subectosomal styles Subectosomal styles rhabdostyles length (µm) rhabdostyles width (µm) length (µm) width (µm) Holotype 143-366-469 6.2-21.4-31.6 1170-2094-4640 12-21.7-29.1 MNHN-IP-2015-1402 QM G335124 (n=143, 36) Paratype 97-326-422 6.8-20.7-28.9 1350-2172-2710 10.2-15.9-21.5 QM G335144 (n=97, 31) Paratype 118-334-444 10.9-19.2-29.2 1010-1749-2350 10.5-17.9-22.3 QM G318701 (n=93, 33)

Microscleres: Absent. Molecular data. DNA barcodes for 28S and CO1 could not be retrieved for the holotype or for the paratypes. All samples underwent two different DNA extractions (see Methods section) and multiple amplification attempts with different deviations from the PCR protocol, but amplification success could not be achieved under the described methods.

FIGURE 4. Transmitted light micrograph of a crossection of the paratype QM G318701 of R. (R.) frondosa sp. nov., showing the well-differentiated axial and extra axial regions of the skeleton, and the restriction of rhabdostyles and styles to the subectosomal and ectosomal regions.

Discussion

The new species belongs to the subgenus Raspaxilla as it has a well differentiated skeleton, with the absence of fibre bundles, with echinating rhabdostyles morphologically different from choansomal styles. It differs from

A NEW SPECIES OF THE SPONGE RASPAILIA (RASPAXILLA) Zootaxa 4410 (2) © 2018 Magnolia Press · 383 species of Aulospongus as it does not contain two categories of rhabdostyles of similar geometry, and lacks the plumose skeleton of that genus. However, this is noted in Hooper et al. (1999) as being variable in the ectosomal skeleton of Aulospongus species. The axial and extra axial skeletal architecture in this species is unique. It differs from R. (Raspaxilla) clathrioides (Lévi, 1967), also from New Caledonia but occurring in shallower waters of the lagoon, which is arborescent, branching with a plumose or plumo-reticulate choanosomal skeleton, vestigial ‘raspailiid’ ectosomal skeleton of spicule bouquets, and spined rhabdostyles. It superficially resembles R. (Raspaxilla) frondula (Whitelegge, 1907) in having a thinly flabellate morphology, radial extra-axial spicule skeleton, and lacking a ‘raspailiid’ ectosomal skeleton, but it has spongin fibres in the axial skeleton cored by styles forming a subrenieroid reticulation, and echinating rhabdostyles with spined distal points. Raspailia (Raspaxilla) hyle (de Laubenfels, 1930) and R. (Raspaxilla) wardi (Hooper, 1991) are also frondose or flabellate and lack or have vestigial ‘raspailiid’ ectosomal skeletons, but have axial fibres cored by spicules in halichondrioid or renieroid reticulate arrangement, and spines covering the distal parts of the rhabdostyles. The new species differs from R. (Raspaxilla) phakellina (Topsent, 1913) from the SE Atlantic in having a thinly foliaceous flabellate growth (compared to digitate branching in the latter), a fibrous axial and spiculose extra-axial skeleton (compared to a skeleton dominated by plumose ascending fibres), much larger choanosomal spicules, non-tylote rhabdostyles (subtylote in the latter), and lacking a specialised raspailiid ectosomal skeleton. This species is also similar to Raspailia (Raspaxilla) mariana (Ridley & Dendy, 1886) and Aulospongus villosa (Thiele, 1898) in that they all have smooth rhabdostyles. Raspailia (Raspaxilla) frondosa sp. nov has a very different skeletal arrangement and morphology to either. It lacks granular spines or subtylote bases on rhabdostyles, which are also slightly larger and stouter and not as well developed as those of R. (R.) mariana. Raspailia (Raspaxilla) frondosa sp. nov. also differs in the extra axial skeleton, lacking the plumose bundles arrangement of R. (R.) mariana. The latter has the embedded bases of the long subectosomal extra-axial styles radiating from the axis to the surface surrounded by plumose bundles of echinating rhabdostyles. Aulospongus villosa does not have any subectosomal extra axial spicules. Further comparisons amongst Raspaxilla species and amongst Aulospongus and other raspailiids with echinating rhabdostyles are discussed in Hooper et al. (1999, 2008). Nevertheless, although R. Raspailia (Raspaxilla) frondosa sp. nov. can morphologically clearly be assigned to subgenus Raspaxilla, this classification may, however, be temporary. Independent molecular data equivocally recover Raspailia as highly non-monophyletic (Erpenbeck et al. 2007 (28S nuclear data), Erpenbeck et al. 2012 (CO1 mitochondrial data), Redmond et al. 2013 (18S nuclear data)). In these gene trees Raspailia subgenera fall in several distant clades suggesting the need for a thorough revision of the raspailiids in the context of their recent classification to Axinellida (Morrow & Cardenas, 2015).

Acknowledgments

We would like to thank the crew and scientific staff from the IRD (Institute de Recherche pour le Développement) on the RV Alis for the collection of specimens. DE acknowledges funding from the Deutsche Forschungsgemeinschaft (DFG) project ER611/3-1 and StudiForscht@LMU, and thanks the Molecular Geo- and Paleobiology Lab (LMU Munich) Members for support, in particular Gabriele Büttner, Nicole Enghuber, Simone Schätzle and Gert Wörheide.

Literature cited

Ekins, M., Erpenbeck, D., Woerheide, G. & Hooper, J.N.A. (2016). A new species of lithistid sponge hiding within the Isabella mirabilis species complex (Porifera: Demospongiae: Tetractinellida) from seamounts of the Norfolk Ridge. Zootaxa, 4136 (3), 433–460. https://doi.org/10.11646/zootaxa.4136.3.2 Erpenbeck, D., List-Armitage, S., Alvarez, B., Degnan, B.M., Wörheide, G. & Hooper, J.N.A. (2007) The systematics of Raspailiidae (Demospongiae: Poecilosclerida: Microcionina) re–analysed with a ribosomal marker. Journal of The Marine Biological Association of The United Kingdom, 87, 1571–1576. https://doi.org/10.1017/S0025315407058201 Erpenbeck, D., Hall, K., Alvarez, B., Büttner, G., Sacher, K., Schätzle, S., Schuster, A., Vargas, S., Hooper, J.N.A. & Wörheide,

384 · Zootaxa 4410 (2) © 2018 Magnolia Press EKINS ET AL. G. (2012) The phylogeny of halichondrid demosponges: past and present re-visited with DNA—barcoding data. Organisms Diversity & Evolution, 12, 57–70. https://doi.org/10.1007/s13127-011-0068-9 Erpenbeck, D., Voigt, O., Al-Aidaroos, A.M., Berumen, M.L., Büttner, G., Catania, D., Guirguis, A.N., Paulay, G., Schätzle, S. & Wörheide, G. (2016) Molecular biodiversity of Red Sea demosponges. Marine Pollution Bulletin, 105, 507–514. https://doi.org/10.1016/j.marpolbul.2015.12.004 Hallmann, E.F. (1916) A Revision of the Genera with Microscleres included, or provisionally included, in the Family Axinellidae, with Descriptions of some Australian Species. Part ii. (Porifera). Proceedings of the Linnean Society of New South Wales, 41 (3), 495–552. Hallmann, E.F. (1917) On the Genera Echinaxia and Rhabdosigma [Porifera]. Proceedings of the Linnean Society of New South Wales, 42 (2), 391–405. https://doi.org/10.5962/bhl.part.4856 Hooper, J.N.A. (1991) Revision of the Family Raspailiidae (Porifera: Demospongiae), with description of Australian species. Invertebrate Taxonomy, 5 (6), 1179–1415. https://doi.org/10.1071/IT9911179 Hooper, J.N.A. (2002) Family Raspailiidae Hentschel, 1923. In: Hooper, J.N.A. & Van Soest, R.W.M. (Eds.) Systema Porifera. Guide to the classification of sponges. Kluwer Academic/Plenum Publishers, New York, Boston, Dordrecht and London, Moscow, pp. 469–510. https://doi.org/10.1007/978-1-4615-0747-5_53 Hooper, J.N.A., Lehnert, H. & Zea, S. (1999) Revision of Aulospongus and other Raspailiidae with rhabdostyles (Porifera: Demospongiae: Poecilosclerida). Memoirs of the Queensland Museum, 43 (2), 649–707. Hooper, J.N.A., Sutcliffe, P. & Schlacher-Hoenlinger, M.A. (2008) New species of Raspailiidae (Porifera: Demospongiae: Poecilosclerida) from southeast Queensland. In: Davie, P.J.F. & Phillips, J.A. (Eds.), Proceedings of the Thirteenth International Marine Biological Workshop, The Marine Fauna and Flora of Moreton Bay, Queensland. Memoirs of the Queensland Museum—Nature, 54 (1), 1–22. Laubenfels, M.W. de (1930) The Sponges of California. Stanford University Bulletin, 5 (98), 24–29. Lévi, C. (1967) Démosponges récoltées en Nouvelle-Calédonie par la Mission Singer–Polignac. Expédition Française sur les récifs coralliens de la Nouvelle–Calédonie. Éditions de la Foundation Singer-Polignac, 2, 13–26. Lévi, C. & Lévi, P. (1983) Démosponges bathyales récoltées par le N/O "Vauban" au sud de la Nouvelle-Calédonie. Bulletin du Muséum National d'Histoire Naturelle, (4A), 5 (4), 931–997. Lévi, C. (1993) Porifera Demospongiae: Spongiaires bathyaux de Nouvelle–Calédonie, récoltés par le Jean Charcot Campagne. BIOCAL 1985, 158, 9–87 Morrow, C. & Cardens, P. (2015) Proposal for a revised classification of the Demospongiae (Porifera). Frontiers in Zoology, 12, 7. https://doi.org/10.1186/s12983-015-0099-8 Nardo, G.D. (1833) Auszug aus einem neuen System der Spongiarien, wonach bereits die Aufstellung in der Universitäts– Sammlung zu Padua gemacht ist. In: Isis, oder Encyclopädische Zeitung Coll. Oken, Jena, pp. 519–523. Norman, A.M. (1878) On the Genus Haliphysema, with descriptions of several forms apparently allied to it. Annals and Magazine of Natural History, Series 5, 1, 264–284. https://doi.org/10.1080/00222937808682332 Payri, C. & Richer de Forges, B. (Eds) (2007) Compendium of marine species from New Caledonia. IRD Documents Scientifiques et Techniques II (7), 1–435. Redmond, N.E., Morrow, C.C., Thacker, R.W., Diaz, M.C., Boury-Esnault, N., & Cardenas, P. (2013) Phylogeny and systematics of demospongiae in light of new small-subunit ribosomal DNA (18S) sequences. Integrative and Comparative Biology, 53 (3), 388–415. https://doi.org/10.1093/icb/ict078 Richer de Forges, B. (2001) Norfolk 1 cruise, RV Alis https://doi.org/10.17600/1100050 Ridley, S.O. & Dendy, A. (1886) Preliminary Report on the Monaxonida collected by the H.M.S. "Challenger". Annals and Magazine of Natural History, Series 5, 18 (108), 325–351, 470–493. https://doi.org/10.1080/00222938609459998 Samadi, S. (2008) Terrasse cruise, RV Alis. Available from: https://doi.org/10.17600/8100100 (accessed 18 September 2017) Sambrook, E., Fritsch, F. & Maniatis, T. (1989) Molecular cloning. Cold Spring Harbor Press., Cold Spring Harbor, New York, 1546 pp. Schlacher-Hoenlinger, M.A., Pisera, A. & Hooper, J.N.A. (2005) Deep–sea "lithistid" assemblages from the Norfolk Ridge (New Caledonia), with description of seven new species and a new genus (Porifera, Demospongiae). Zoosystema, 27 (4), 649–698. Van Soest, R.W.M., Boury-Esnault, N., Hooper, J.N.A., Rützler, K., De Voogd, N.J., Alvarez De Glasby, B., Hajdu, E., Pisera, A.B., Mancnoi, R., Schoenberg, C., Klautau, M., Picton, B., Kelly, M., Vacelet, J., Dohrmann, M., Díaz, M.-C., Cardens, P. & Carballo, J.L. (2017) World Porifera Database. Available from: http://www.marinespecies.org/porifera (accessed 8 May 2017)

A NEW SPECIES OF THE SPONGE RASPAILIA (RASPAXILLA) Zootaxa 4410 (2) © 2018 Magnolia Press · 385 Thiele, J. (1898) Studien über pazifische Spongien. I. Heft. Zoologica, 24, 1–72. Topsent, E. (1913) Spongiaires de l'Expédition Antarctique Nationale Ecossaise. Transactions of the Royal Society of Edinburgh, 49 (3), 579–643. https://doi.org/10.1017/S0080456800013119 Wells, H.W., Wells, M.J. & Gray, I.E. (1960) Marine sponges of North Carolina. Journal of the Elisha Mitchell Scientific Society, University of North Carolina at Chapel Hill, 76, 200–245. Whitelegge, T. (1907) Sponges. Part I.—Addenda. Part 2. Monaxonida continued. In Scientific Results of the Trawling Expedition of H.M.C.S. "Thetis" Off the Coast of New South Wales in February and March, 1898. Memoirs of the Australian Museum, 4 (10), 487–515.