Records of the Western Australian Museum 19: 65-89 (1998). Revision of the marine sponge genus Caulospongia Saville Kent, 1871 (Demospongiae: Hadromerida). Part 1. Morphological and skeletal characters Jane Fromont Department of Aquatic Zoology, Western Australian Museum, Francis Street, Perth, Western Australia 6000, Australia. Email: [email protected] Abstract - The sponge genus Caulospongia is reviewed and redefined to accommodate eight closely related species that belong to the genus. Four new species, Caulospongia amplexa, C. reticulata, C. venosa and C. biflabellata are described, and C. pennatula (Lamarck, 1814), C. perfoliata (Lamarck, 1814), and C. plicata Saville Kent (1871) are redescribed with reference to the type specimens and new material. C. elegans (Lendenfeld, 1888) is redescribed from the type material. The scope of the genus is discussed with respect to morphological and skeletal characters and its location within the family Suberitidae is confirmed in the light of these characters. As a consequence of examination of type material the synonymy of the genus Plectodendron Lendenfeld (1888) with Caulospongia Saville Kent (1871) is confirmed. A preliminary assessment is made of the biogeography of the genus, which is predominantly Western Australian. INTRODUCTION branching network, and bore no resemblance to the In 1814, Lamarck described Spongia perfoliata and three dimensional whorls characteristic of S. pennatula, two species of stalked sponges with Caulospongia. When Hallmann (1914) redescribed an unusual foliaceous morphology. Their common P. elegans he synonymised Plectodendron with feature was to have a sponge body composed of Caulospongia on the basis of identical skeletal and leaf-like lobes around a central stem. Subsequently, spicule morphology. Since this time no further Saville Kent (1871) established a new genus work has been carried out on these unusual Caulospongia for two species he described: C. sponges. Hooper (1984) mentioned a specimen of verticillata and C. plicata. He established the genus C. perfoliata collected from the Timor Sea, and for sponges with a central stem surrounded by Hooper and Wiedenmayer (1994) retain the leaf-like whorls or spiral convolutions and with a synonymy of Plectodendron with Caulospongia and skeleton of fibre and spicules. list three valid species, Saville Kent did not mention the material 1. C. elegans (Lendenfeld, 1888) described by Lamarck (1814) and it is assumed that 2. C. pennatula (Lamarck, 1814) he was unaware that species had previously been 3. C. perfoliata (Lamarck, 1814) with the synonyms: described that were congeneric with C. verticillata C. plicata Saville Kent, 1871 and C. plicata. Bowerbank (1876) also failed to refer C. verticillata Saville Kent, 1871 to previous publications that described species Chalina verticillata Bowerbank, 1876 with this unusual morphology when he described Some questions became obvious as a consequence a specimen collected from Fremantle, Western of the review of the literature on these sponges Australia as Chalina verticillata. Topsent (1932) summarised above. noted this incredible lack of knowledge of earlier • Should the genus Plectodendron remain published references by both Saville Kent and synonymised with Caulospongia? Bowerbank when he redescribed Lamarck's • How many valid species of Caulospongia are species. there? Meanwhile, in 1888, Lendenfeld had defined • Is the family Suberitidae, order Hadromerida, another new genus Plectodendron with the type the most appropriate taxon for the genus? species P. elegans collected on the New South Wales Examination of the collections at the Western coast. This genus was closely related to Australian Museum found 12 wet specimens and Caulospongia as it had tylostyles for spicules and numerous dry specimens of Caulospongia; the latter fibre in the skeleton, but in this genus the sponge are beachwash material and in a condition too poor body extended from a central stalk into a regular for descriptive purposes. Beachwash specimens of 66 J. Fromont Caulospongia are regularly found on local Perth concentrated nitric acid, followed by two beaches after winter storms. Five additional wet consecutive washes of distilled water and two of specimens have since been added to the collection, absolute alcohol. Spicule extracts were dried on a with good in situ colour photographs and habitat glass slide and mounted in DePeX, Gurr Products. descriptions. Four of these specimens were Spicule measurements are based on 15 spicules per collected from the South West coast (K. Bancroft specimen selected at random. The skeleton was and CALM; J. Fromont) and the other from the prepared by cutting a representative section at Abrolhos Islands (J. Fromont). The abundance of right angles to the surface of the sponge, preserved material indicated the prevalence of the dehydrating it through an ascending ethanol series, genus in WA waters, and prompted a redescription clearing in xylene and infiltrating in paraffin wax and re-evaluation of species. This examination (Histoplast, Shandon Elliot) using an automatic immediately indicated a suite of problems, the first tissue processor on a nine hour cycle. The sponge being to determine how many species were tissue was further infiltrated with paraffin under a represented in the WAM collections, with the vacuum of 635mm Hg for 30 minutes prior to second and related problem being the ability to embedding. Blocks were sectioned at 90 pm discriminate precisely between these thickness with a Leitz slide microtome, and section morphologicaIly similar species. Finally, defining rolling was eliminated by placing filter paper, the boundaries of the genus Caulospongia also moistened with distilled water, on top of the appeared to be very complex. As an aid to paraffin block. Sections were placed on a glass slide resolving these problems additional material was smeared with egg albumin for adhesion, dried loaned from the Northern Territory Museum of overnight at 60°C and dehydrated in two changes Arts and Sciences, the South Australian Museum, of xylene. They were mounted with Eukitt, Agar and the Queensland Museum. The total number of Scientific. wet specimens available for examination was 37, Abbreviations used in the text: AIMS/NCI, and all available type material was also examined Marine Bioproducts Group, Australian Institute of (Table 1). Marine Science, (Zoological collections now housed in the QM, Brisbane); AM, Australian Museum, Sydney; BMNH Natural History MATERIALS AND METHODS Museum, London; CALM, Department of Material from various museums (listed at the end Conservation and Land Management, Perth; of this section) was examined during the course of MNHN, Museum National d'Histoire Naturelle, this study. Wet specimens were preserved in 70% Paris; NTM, Northern Territory Museum of Arts ethanol. Skeletal structure and spicule morphology and Sciences, Darwin; QM, Queensland Museum, were examined using light microscopy. Spicules Brisbane; SAM, South Australian Museum, were prepared by boiling small pieces of sponge, Adelaide; WAM, Western Australian Museum, including ectosome and choanosome, in Perth. Table 1 Type material relevant to this study. SPECIES AUTHOR/YEAR LOCALITY MATERIAL NOTES EXAMINED Spongia Lamarck, 1814 Seas of Australia Holotype: MNHN perfoliata (Peron & Leseur) LMIM DT 3368, dry Spongia Lamarck,1814 Shark Bay, WA Holotype: MNHN pennatula (Peron & Leseur) LBIM DT 583, dry Caulospongia Saville Kent, 1871 North Australia Not examined, verticillata Type destroyed Caulospongia Saville Kent, 1871 No locality data Holotype: BMNH Beachwash plicata 1870:12:22:2, dry specimen Chalina Bowerbank, 1876 Fremantle, WA Holotype: BMNH Beachwash verticillata 1877:5:21:6, dry specimen Plectodendron Lendenfeld, 1888 Broughton Island, Lectotype: AM elegans NSW G9186, wet Plectodendron Lendenfeld, 1888 Port Jackson, Paralectotype: AM elegans NSW Z5221, wet Plectodendron Lendenfeld, 1888 Port Jackson, Paralectotype: AM fragments elegans NSW Z5271, dry Australian species of Caulospongia 67 SYSTEMATICS being some species of Suberites such as S. massa which is branching and erect and the genus Order Hadromerida Rhizaxinella which has a globular, ovoid, Diagnosis cylindrical, or branching morphology with a basal Megasclere skeletons composed of monactinal stalk. Most of the genera of this family are small spicules which are usually tylostyles, subtylostyles, mounds or balls (e.g. Aaptos) massive forms (e.g. or styles. A size and locational distinction is some species of Laxosuberites and Suberites) or thin usually found in the megascleres with peripheral encrustations (e.g. Terpios, Prosuberites, and some megascleres smaller than choanosomal ones. A species of Laxosuberites). Riitzler and Smith (1993) radial construction occurs in the outer layers but noted that the family Suberitidae contained genera may not occur internally. Microscleres, if present, distinguished by shape of the adult sponge, by are euasters or derivatives thereof [abbreviated skeleton structure, and by spicule orientation, type from Hartman (1982)]. and distribution. In summary, the genus Caulospongia is most appropriately located within the family Remarks Suberitidae. The genus has simple spiculation, one The Hadromerida is a relatively well defined size category of tylostyles, and surface brushes of order although in some families the simplicity of spicules. The genus is unusual within this family in skeletal characters makes lower taxonomic level having a well organised choanosomal