First Record of the Genus Vetulina Schmidt, 1879
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Mar Biodiv DOI 10.1007/s12526-017-0658-7 ORIGINAL PAPER First record of the genus Vetulina Schmidt, 1879 (Porifera: Demospongiae: Sphaerocladina) from the Indian Ocean with the description of two new species: biogeographic and evolutionary significance Andrzej Pisera1 & Magdalena Łukowiak1 & Jane Fromont2 & Astrid Schuster3 Received: 24 August 2016 /Revised: 23 October 2016 /Accepted: 10 February 2017 # The Author(s) 2017. This article is published with open access at Springerlink.com Abstract Two new species of the genus Vetulina Schmidt, 1879 Keywords Lithistids . Vetulinidae . Vetulina indica sp. nov . (Demospongiae, Vetulinidae, Sphaerocladina) were found off the Vetulina rugosa sp. nov . Tethys Sea coast of Western Australia (Indian Ocean). This genus is charac- terized by acrepid polyaxial desmas (sphaeroclones) equipped with arborescent branched outgrowths with spine-like processes Introduction and isometric styles as microscleres. Vetulina indica sp. nov. is an irregular, laterally folded ear-shaped cup with smooth surfaces, Lithistid sponges are known from almost all temperate and and V. rugosa sp. nov. is similar in shape but with a distinctive tropical oceans but are generally restricted to deeper water of ribbed inner surface. Both species are very similar in spicule greater than 80 m depth (Kelly 2007). The best-described composition, but are distinguished by their gross morphology lithistid faunas occur in the tropical western Atlantic (see and pattern of canal openings on the surface. Despite the fact Pomponi et al. 2001 and references therein) and south-west that we could not distinguish the two specimens based on mo- Pacific (see Kelly 2007 and references therein). lecular (CO1) data, we consider them as two separate species Lithistids have rigid skeletons comprised of interlocking based on the morphological species concept. Our molecular phy- desmas and are consequently easily fossilized. However, logeny confirms again that Vetulina is sister to spongillids (fresh- there is no reliable fossil record of Vetulina known to date, water sponges). This is the first occurrence of this genus outside as the report by Moret (1926) of a sponge from the Turonian the Caribbean Atlantic, and the first report from the Indian (Late Cretaceous) of France is based solely on general mor- Ocean. Such a disjunct distribution is considered here to be a phological resemblance (no spicules are known). Lithistids relict of a once widely distributed sponge population in the with sphaeroclonar desmas are known from Jurassic and ancient Tethys Sea. Cretaceous rocks (with one Eocene occurrence in Italy; Frisone et al. 2016), mainly in Europe, and are attributed to Communicated by P. Martinez Arbizu 10 genera (Reid 2004). The first Mesozoic lithistid This article is registered in ZooBank under urn: lsid:zoobank.org: demosponge with sphaeroclonar desmas is from the pub:0895227E-C2F8-41F3-B227-036C80BF83A5 Bathonian (Middle Jurassic) of India (Mehl and Fürsich 1997). There are even Palaeozoic lithistid demosponges bear- * Andrzej Pisera ing sphaeroclonar desmas grouped in the family [email protected] Astylospongiidae Zittel 1877 (Ordovician–Permian) (Finks and Rigby 2004), but their relationship to younger Mesozoic ∼ 1 Institute of Paleobiology, Polish Academy of Sciences, ul. Twarda and Recent forms is unclear, due to the large ( 200 Ma years) 51/55, 00-818 Warszawa, Poland stratigraphic gap that separates them. ‘ 2 Department of Aquatic Zoology, Western Australian Museum, Until recently, lithistids were grouped as lithistid Locked Bag 49, Welshpool DC, WA 6986, Australia Demospongiae’ for convenience, but were known to be poly- 3 Department of Earth & Environmental Sciences, Palaeontology and phyletic (Pisera and Lévi 2002). With recent molecular stud- Geobiology, Ludwig-Maximilians-Universität München, ies, this has been formally abandoned and lithistid species Richard-Wagner-Str. 10, 80333 Munich, Germany have been allocated to 13 families in 4 orders (Morrow and Mar Biodiv Cárdenas 2015; Schuster et al. 2015). The Vetulinidae Von illustrations depicting the morphology of these spicules pre- Lendenfeld 1903 are a single family in the Sphaerocladina, cludes deciding whether or not they are strongyles. On the an order that already existed in the fossil classification other hand, in his earlier publication on V. stalactites,Sollas (Morrow and Cárdenas 2015). (1885) never mentioned strongyles in his descriptions and The genus Vetulina Schmidt 1879 is currently the only only illustrated Bthe simple cylindrical spicules^ as belonging living representative of a once more diversified Mesozoic to V. stalactites (Sollas 1885: pl. IV, fig. 2). Indeed, they re- group of lithistid demosponges with sphaeroclonar desmas semble strongyles more than any other spicule type, including (Pisera and Lévi 2002; Reid 2004 with references), that have the styles found in this study, but the minimum attention given older Paleozoic relatives (Pisera 2002). So far, the only known to describe them, and a single illustrated spicule, allows us to extant representative of this genus is Vetulina stalactites have justified doubts about their real nature. Schmidt 1879 reported from Barbados at 180 m depth The size of the microscleres from the studied specimens (Schmidt 1879; Sollas 1885, 1888; Soest and Stentoft 1988; (80–110 μm) may raise some doubts as to whether they are Pisera and Lévi 2002). However, V. stalactites is rarely report- micro- or megascleres. The threshold between micro- and ed and consequently poorly known. megascleres is generally accepted as 50 μm (van Soest In this paper, we report two new species of Vetulina,de- et al. 2012), although there are some spicules, such as scribing their morphology, illustrating their spiculation in de- sterrasters and selenasters, that are considered to be tail, and discussing their distribution and their molecular microscleres despite their large size. In the species de- barcodes. scribed here, the size is not decisive as we consider the position/role of the spicules in the skeleton to conform more to the definition of microscleres. Materials and methods Genus Vetulina Schmidt 1879 Diagnosis: As for the family. The specimens were collected during an expedition on the RV Remarks: As for the family. The only fossil record of the Southern Surveyor in 2007 which sampled the northwestern genus from the upper Cretaceous rocks by Moret (1926)is continental shelf margin of Western Australia (12°–22°S), in considered here to be unreliable because it is based solely on the eastern Indian Ocean (Fig. 1;Fromontetal.2012). similarities of general morphology (no spicules are known). Equipment used were a Sherman sled and beam trawl that Type species: Vetulina stalactites Schmidt 1879 (by sampled hard substrates. Voucher specimens were monotypy). photographed on deck, labelled and preserved in 75% ethanol. Vetulina indica sp. nov. They are housed in the collections of the Western Australian Figs. 2a, 3a–c, 4, 5, 6 Museum Harry Butler Research Centre, Welshpool. Holotype: Western Australia, Ashmore Reef (12°26′42″S, 123°36′03″Eto12°26′58″S, 123°36′35″E), 95 m, M. Salotti on RV Southern Surveyor, beam trawl, SS0507/188, 06/07/ Systematic description 2007 (WAM Z35842). Diagnosis: Laterally flattened ear-shaped low cup with Class Demospongiae smooth surfaces; no special ectosomal spicules; choanosomal Order Sphaerocladina Schrammen 1924 spicules acrepid polyaxial desmas (sphaeroclones) with small- Family Vetulinidae Lendenfeld 1903 er arborescent outgrowths with minute spines; microscleres Emended diagnosis: Lithistid Demospongiae with acrepid straight to slightly bent isodiametric styles with mucronate polyaxial (sphaeroclones to astroclones) desmas; no other tips. megascleres; microscleres when present are microstyles or Description: Laterally flattened irregular, convoluted, ear- ?strongyles (modified after Pisera and Lévi 2002). shaped cup with a smaller cup outgrowth at the base (Fig. 2a). Remarks: Emendation to the diagnosis was required as the Dimensions of specimen: 10 cm high, apically 10 × 14 cm new species described here have microscleres that were not wide. Small basal lobe: 4 cm high, 6 × 3 cm wide. Cup walls included in the family diagnosis published in the Systema 1 cm thick with convoluted margins slightly sloping towards Porifera (Pisera and Lévi 2002). Microscleres were not report- the outer surface. Both surfaces smooth. Outer surface porous ed in the original description of the type of the genus, with visible growth lines (Fig. 3b, c) and large pores V. stalactites Schmidt (1879), a specimen which was poorly (?oscules) from 100–400 μm in diameter, irregularly distrib- preserved. However, they were described from better pre- uted (Figs. 3c. 4a, b), surrounded by rare styles (Fig. 4b). Inner served specimens investigated by Sollas (1885, 1888), al- surface very smooth (Fig. 3a) with rare low knobs (<1 mm though they were interpreted later as contamination (Pisera high, up to 3 × 3 mm wide) and small openings (?ostia) irreg- and Lévi 2002). Sollas (1888) described them as cylindrical ularly distributed, up to 50 μm in diameter (Fig. 5a–c). Live strongyles, 40–350 μminsize.However,thelackof color light yellow, fawn in ethanol (Fig. 2a). Mar Biodiv Fig. 1 Locations of Station 116 (specimen WAM Z36103) and Station 188 (specimen WAM 35842). Collection sites marked with asterisks Choanosomal spicules acrepid polyaxial desmas interwoven spinose finger-like outgrowths (Fig. 4e, f). (sphaeroclones) to 250 μm diameter (Figs.