Revision of the Genus Trachytedania (Porifera: Poecilosclerida) with A

Revision of the Genus Trachytedania (Porifera: Poecilosclerida) with A

J. Mar. Biol. Ass. U.K. 2001), 81,569^579 Printed in the United Kingdom Revision of the genus Trachytedania Porifera: Poecilosclerida) with a description of Trachytedania ferrolensis sp. nov. from the north-east Atlantic F.J. Cristobo*and V. Urgorri O *Departamento de Biodiversidade e Recursos Marin¬ os, Instituto de Acuicultura, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Spain. E-mail: [email protected] OLaboratorio de Zoolox|¨a Marin¬ a, Departamento de Biolox|¨a Animal, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Spain. E-mail: [email protected] The genus Trachytedania Ridley, 1881 Porifera: Poecilosclerida), includes those tedaniidae sponges characterized by the presence of acanthostyles. To date, only ¢ve species of the genus Trachytedania have been described of which only three actually belong to this genus. Other species described as Tedania could be considered as Trachytedania because of the presence of acanthostyles in their skeletons. Some authors propose retaining Trachytedania as a subgenus of Tedania because of its skeletal structure. In this work, a taxonomic revision and consideration of the validity of the genus is provided. The morphology and anatomy of Trachytedania ferrolensis sp. nov. from the R|¨a de Ferrol Spain, north-east Atlantic) are described in detail, and the types of the three valid species described as Trachytedania to date: Trachytedania spinata, Trachytedania patagonica and Trachytedania biraphidora are studied. A key to this genus is provided. INTRODUCTION MATERIALS AND METHODS The position of the Family Tedaniidae within the The specimens were collected by SCUBA divers and by Poecilosclerida is still disputed. Species of the genus dredging using a naturalist benthic dredge Holme & Tedania Gray, 1867, have always been di¤cult to di¡er- McIntyre, 1984) in the sublittoral zones of R|¨a de Ferrol entiate clearly Bergquist & Fromont, 1988) and the value Spain). Material from the following Museum collections of the genus Trachytedania has been called into question at was also examined: types of Trachytedania biraphidora di¡erent times since 1881. In Ridley's 1881) original Boury-Esnault, 1973 from the Muse¨ um National description based on the species Trachytedania spinata,he d'Histoire Naturelle, Paris LBIM N8D. NBE 974); types remarks that this genus di¡ers from all the known of Trachytedania spinata Ridley BMNH: 1879.12.27.9) and species of Tedania in having three kinds of spicules, one Trachytedania patagonica Ridley & Dendy BMNH: of them being spined. Ridley & Dendy 1886) described 1887.5.2.205) from the British Museum Natural History), a new species, Trachytedania patagonica with entirely spined London Figure 1). acanthostyles. Hope 1889) described one species in- The methods followed were those of Ru« tzler 1978), correctly identi¢ed as Trachytedania T. e c h i n a t a ), because it Uriz 1978, 1986) and Cristobo et al. 1993). Spicules does not have onychaetes. Another erroneous identi¢ca- were examined under Hitachi S570 and Leo 435VP tion is that of Trachytedania arborea Ke« ller, 1891) that scanning electron microscopes SEMs). Underwater has oxeas and onychaetes but does not have acantho- photographs were taken with a Nikonos V camera and styles. Boury-Esnault 1973) describes a valid species, SB-102 £ash. The megasclere spicules were measured Trachytedania biraphidora with two size classes of using a light microscope which was adapted to a Kontron onychaetes from the Atlantic coasts of South America. Bildanalyse Videoplan, equipped with CPU, TV camera, Di¡erent authors have sometimes described some of the TV monitor and digitalizing tablet. This made it possible preceding species, attributing them to the genus Tedania, to take a large number of measurements. Microscleres while another Tedania could be included in Trachyedania were measured using SEM. because of the presence of acanthostyles in its skeleton. Owing to this confusion we are revising the genus begin- SYSTEMATICS ning with a new diagnosis after reviewing types of species described as Trachytedania, and have completed their Phylum PORIFERA Grant, 1836 descriptions. In this paper, we also revise those species of Class DEMOSPONGIAE Sollas 1885 Tedania with spined styles or acanthostyles in order to Order POECILOSCLERIDA Topsent, 1928 clarify the taxonomy of the group. Finally, in this work Suborder MYXILLINA Hajdu, Van Soest & Hooper, 1994 we describe a new species of Trachytedania T.ferrolensis) from the north-east Atlantic. Fa m i l y TEDANIIDAE Ridley & Dendy, 1886 Journal of the Marine Biological Association of the United Kingdom 2001) 570 F.J. Cristobo andV.Urgorri Revision of the genusTrachytedania Porifera) Figure 1. Map of the world showing the sites of collection of Trachytedania species: *, T. spinata; *, T. patagonica; ~, T. biraphidora; *, T. ferrolensis; ~, T. spinostyla; &, T. in£ata; &, T. microrhaphidiophora. Diagnosis is composed of tornotes with perpendicular and paratan- Encrusting, massive or digitate Poecilosclerida with a gential arrangement. Onychaetes are abundant, free in choanosomal skeleton predominantly plumo-reticulate or ectosome and choanosome. even plumose of monactinal and/or diactinal megascleres Spicules megascleres. Acanthostyles straight or slightly which are organized in tracts of styles, acanthostyles or curved with few short spines predominantly at the base of oxeas, enclosed within light or moderate spongin ¢bres, the spicule, 170^200 mm. Tornotes straight, smooth, or with no visible spongin, and spicules merely cemented isodiametric with apex abruptly pointed, 140^170 mm. together with collagen at their nodes. The ectosomal Onychaetes very ¢ne slightly curved, 130^15 0 mm. skeleton consists of diactinal megascleres which may be Habitat: on both valves of small Pecten,18.2m. distinguished from the choanosomal megascleres either in Distribution: Portland Bay, Chile. South-west coast of morphology or size; these spicules are tylotes or tornotes Patagonia. usually with basal spines, lying tangentially, paratangen- tially or erect on the surface. Microscleres are onychaetes. Remarks Chelae are absent. After revision of the holotype of Trachytedania spinata Ridley, 1881, we have observed the presence of acanthos- tyles on the skeleton of this species Figure 2B). Those GenusTrachytedania Ridley, 1881 nearest the base of the sponge possess more spines on the Trachytedania spinata Ridley, 1881 head than those situated at the frontal part of the ecto- Material examined some, which are generally smooth. This fact is the reason Type, British Museum Natural History) BMNH: why di¡erent authorss question the validity of this genus 1879.12.27.9) Figure 2). Bergquist & Fromont, 1988; Desqueyroux-Faundez & Original description of the holotype in Ridley 1881:122). Soest, 1996). However, it is necessary to bear in mind the New data from the present authors' reexamination of fact that the specimen collected by Ridley 1881) was the holotype: found on both valves of Pecten and that the existing Shape and size: encrusting, laminar. 10.2Â9.1Â2 mm. specimen in the British Museum Natural History) Colour: yellowish white in spirit. BMNH: 1879.12.27.9) Figure 2A) is separated from the Surface: even, covered with a ¢ne membrane. Oscula shell of the mollusc. Probably the basal spongin plate with not detected; possibly represented by irregular depres- acanthostyles became stuck to the shell, and for this sions. Ostia not detected. reason it is possible that the acanthostyles closest to the Texture: smooth. base the spiniest) have disappeared on separation of the Skeleton: choanosomal architecture is composed of sponge from substrate to which it had been attached. On loosely aggregated acanthostyles in an isotropic reticula- the other hand this does not occur with other species of tion of three or four spicules, and transversal tracts of the genus that have real acanthostyles and not just spined acanthostyles with few spines. The choanosomal skeleton styles Figures 3^6). Journal of the Marine Biological Association of the United Kingdom 2001) Revision of the genusTrachytedania Por ife ra) F.J. Cristobo andV.Urgorri 571 Figure 2. Trachytedania spinata Ridley, 1881; Holotype. A) habitus; B) acanthostyles at the base; C&D) transverse section of theskeleton; E)tractsofacanthostyles; F)estosomalspicules. Trachytedania patagonica Ridley & Dendy, 1886 similar spicules are scattered throughout the ectosome, Material examined which together with some of the stylote spicules, form a Holotype, British Museum Natural History) BMNH: very sparse and irregular dermal reticulation. 1887.5.2.205) Figure 3A,B). Spicules: a) Megascleres. Acanthostyles rather stout Original description of the holotype in Ridley & slightly curved, spined all over with the spination most Dendy, 1886: 336; 1887: 57. marked at the base; size: 350Â12.5 mm. Tornotes, tapering Shape and size: irregularly shaped, massive, 37 mm. gradually to a slightly hastate point at each end; size: Colour: pale yellow in spirit. 245Â7 mm. b) Microscleres. Onychaetes very ¢ne slightly Surface: uneven with slight traces of hispidation. thicker at one end than at the other; length: 200 mm Oscula small, scattered. Ostia scattered throughout some spined near the broader end with ¢ne spines directed parts of the dermal membrane. towards that end of the spicule. Texture: soft and crumbling. Habitat: bottom blue mud, 320 m. Skeleton: very loose and irregular, consisting of a Distribution: south-west coast of Patagonia. somewhat isodictyal

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