a new species of biemna (porifera: poecilosclerida) … · a new species of biemna (porifera:...

A new species of Biemna (Porifera: Poecilosclerida) fromAntarctica: Biemna strongylota

Pilar R|¤ os* and Javier CristoboO

*C/Mar|¤ a n8 39, 28, 15624 Ares, A Corun‹ a, Spain.ODepartamento de Zoolog|¤ a yAntropolog|¤ a F|¤ sica, Universidad de Alcala¤ de Henares, Madrid, Spain.

E-mails: [email protected] and [email protected]

A new species of Biemna, Biemna strongylota sp. nov. is described from Antarctica. The new species iscompared to other Antarctic species of Biemna, B. chilensis and B. macrorhaphis from which it di¡ers in thatit possesses strongyle megascleres, instead of styles, and of the microsclere complement which includesmicroxeas, raphides and two categories of sigmata.

INTRODUCTION

Porifera represent one of the most important elements inthe Antarctic biota due to their diversity and to theirdominance in diverse areas (Sara¤ et al., 1992). In the

Antarctic benthos, at depths of 100m these sponges canattain a biomass comparable to the highest found intropical areas (Beliaev & Ushakov, 1957). This circum-stance, together with the fact that these areas are rich insilica (Demospongiae and Hexactinellida), the great size

J. Mar. Biol. Ass. U.K. (2006), 86, 949^955Printed in the United Kingdom

Journal of the Marine Biological Association of the United Kingdom (2006)

Figure 1. Map of the Antarctic Peninsula and Bellingshausen Sea. Location of Biemna strongylota is indicated by * in the South ofGerlache Strait near Anvers Island.

of their spicules, their uniform distribution and theshortage of calcareous sponges, are the main aspects thatcharacterize them.

Desmacellidae are poecilosclerids lacking chelae.Noticeable in this group is the preponderance of toxic ordermatitis-producing sponges. Six valid genera areincluded in this family. Only two are recorded in Antarcticwaters (Sara¤ et al., 1992): Desmacella and Biemna.

With respect to the taxonomic position of these twogenera and the family, Hallman (1916) put forward thehypothesis that Desmacella Schmidt, 1870 (andDesmacelidae) was close to Axinellidae Carter 1875; whileGray, 1867 considered Biemna to be in a separate familyBiemnidae which was closer to the Mycalidae. Inaccordance with Hajdu & van Soest (2002) we prefer toassign both Biemna and Desmacella to the Poeciloscleridaand to the same family. Since Desmacellidae has priorityover Biemnidae, the latter is designated a juniorsynonym.

During the Spanish Antarctic expedition ‘Bentart 03’,sponges were collected from several locations, principallyin the Bellingshausen Sea and surrounding areas suchas the Gerlache Strait, at depths from 48 to 2045m.The collection contained material of a species ofBiemna, which appeared to di¡er from the two Biemna

species recorded from Antarctic waters so far, B. chilensisThiele, 1905 and B. macrorhaphis Hentschel, 1914.The present study gives the description of this newmaterial.

MATERIALS AND METHODS

The material examined originates from the GerlacheStrait (Antarctica), 64855’53’’S 63836’41’’W (Figure 1),and was collected at a depth of 656m by a 2.01m Agassiztrawl in February 2003.

The specimens were preserved in 70% ethanol. In orderto study the spicules, the organic matter was digested withnitric acid taken to boiling point following the methods ofRu« tzler (1978) and Cristobo et al. (1993). Spicules wereexamined with a Leica S440 scanning electron micro-scope. The data for spicule sizes are based on 25 measure-ments for each spicule category, comprising minimum,maximum and average lengths in micrometres (mm). Theclassi¢cation system adopted in this work is that proposedby Hajdu & van Soest (2002) in the Systema Porifera

(Hooper & van Soest, 2002).The holotype and one paratype have been deposited in

the Porifera collection of the Museo Nacional de CienciasNaturales, Madrid (MNCN).The other paratype has beendeposited in the collections of the Muse¤ um Nationald’Histoire Naturelle, Paris (MNHN).

SYSTEMATICS

Class DEMOSPONGIAE Sollas, 1885Order POECILOSCLERIDATopsent, 1928

Suborder MYCALINA Hajdu, van Soest & Hooper, 1994Family Desmacellidae Ridley & Dendy, 1886

Genus Biemna Gray, 1867Biemna strongylota sp. nov.

(Figure 2)

Type material

Holotype: Museo Nacional de Ciencias Naturales,Madrid. MNCN1.01/360.

Paratype 1: Muse¤ um National d’Histoire Naturelle,Paris. MNHN DCL 3900.

Paratype 2: Museo Nacional de Ciencias Naturales,Madrid. MNCN1.01/361.

Type locality: Gerlache Strait (Antarctic). 64855’53’’S63836’41’’W, 656m depth. Coll. RV ‘Hespe¤ rides’, 25February 2003. Three specimens. Muddy substrate with alittle gravel and sand.

External morphology

Erect sponges, supported by a short stalk 5 to 10mmlong and 1.5 to 2mm in diameter at the base. From thesubstrate to the sponge body, the stem gets graduallythicker until its diameter increases from 3 to 5mm. Thesurface features in this stalk region are di¡erent from therest of the sponge as it is smoother and ¢nely hispidbearing small tufts of strongyles and microxeas. Theheight of the specimens varies between 34 and 36mm,while the largest diameter is 10 to 17mm. The surface ofthe main body is rough to the touch, caused by the endsof the choanosomal ¢bres which give it a curly appearance.Neither pores nor oscules were observed. Colour white inethanol (Figure 2).

Skeleton

The choanosomal skeleton (Figure 3) is formed bybundles of 3^6 spicules, surrounded by spongin, that

950 P. R|¤ os and J. Cristobo New species of Biemna (Porifera) from Antarctica


Figure 2. Biemna strongylota sp. nov. habitus (A) paratype 1;(B) paratype 2; and (C), holotype.

splits dichotomously and form angles of 458, showing aplumo-reticulate appearance. The main bundles measure70^200 (130) mm in length and are connected at points tosecondary bundles, which are 20^110 (74) mm thick. Thesesecondary bundles are formed of 1^4 strongyles at anglesof 90^1508 in relation to the main bundles. Microscleresare very abundant around these bundles. The largest

sigmata sometimes form small groups (sigmodragmata)while the raphides occur both loose in the choanosomeand also in trichodragmata.

The ectosomal skeleton is not apparent inmost of the bodyin those specimens where only the ends of the bundles ofstrongyles are found at the surface. This ectosomal skeletonis composed only of microscleres, with the raphides

New species of Biemna (Porifera) from Antarctica P. R|¤ os and J. Cristobo 951


Figure 3. Biemna strongylota sp. nov. skeleton.

occurring in trichodragmata and the microxeas loose andvery abundant, sometimes forming groups in a disordereddisposition. Sigmata of two sizes are also frequent.

Spicules (Figures 4 & 5)

Megascleres: strongyles are abundant, thick andstraight or slightly curved at the tips, although a sharper

curvature was observed in the basal third in some of them.One of the ends is smooth and the other has smallgranulations, which appear as indistinct spines. Some ofthem seem to get thinner towards one end, resemblingstyles. Size: 400^640 (553)�19^30 (26.5) mm.

Microscleres: fusiform microxeas are very frequent.Size: 58^86 (72)�2 mm.



Figure 4. Biemna strongylota sp. nov. (A) Strongyles; (B) raphide; (C) microxea; (D) sigma I; and (E) sigma II.

Raphides: very abundant and thin, both ends aresharp-pointed. They are grouped in trichodragmata.Size: 130^238 (179) mm long.

Sigmata I (C-shaped sigmas) have the shape of a £agel-lated sigma with both ends sharp-pointed, one oppositethe other, and curved along the inner region. Size: 35^100 (82)�2 mm.

Sigmata II (C-shaped sigmas) are smaller, with short,sharp ends. They are slightly curved along the innerregion. Size: 10^22 (16)�1 mm.

Etymology

The species name refers to the presence of strongyles asmegascleres.



Figure 5. Biemna strongylota sp. nov. (A) Strongyle; (B&C) detail of extremities of strongyle; (D) raphide; (E) microxea; (F) sigmaI; and (G) sigma II.

DISCUSSION

According to Hajdu & van Soest (2002) only two ofapproximately 55 species belonging to this genus havebeen reported in Antarctic waters: Biemna chilensisThiele,1905 and B. macrorhaphis Hentschel, 1914, both studied byBurton (1932). Biemna chilensis Thiele, 1905, is a specieswith the following characteristics: styles present, raphidesof one size and sigmata of two size-categories (Thiele,1905). Apart from the original description, this specieswas also collected by Desqueyroux (1972) at the samelocation, by Koltun (1976) at three di¡erent Antarcticlocations and by Boury-Esnault & Van Beveren (1982)from the Kerguelen Islands. The descriptions by each ofthese authors di¡er from the original description:Desqueyroux records only one category of sigmata with awide size-range; in Koltun’s description the styles and theraphides are much longer than those given by the otherauthors (1500 mm) and he does not mention the presenceof sigmata; the spicular dimensions recorded by Boury-Esnault & Van Beveren are the most similar to theoriginal description (Table 1).

Biemna macrorhaphis Hentschel, 1914 has straight styles,curved along one-third of its length, sigmata with a widesize-range and very long raphides (Hentschel, 1914).

The species studied in this report presents distinct andobvious di¡erences from both of these species because,apart from possessing strongyles as the main spicule type,the dimensions of sigmata, raphides and microxeas clearlydi¡er from those of the other Antarctic species (Table 1).

The distinction of Biemna and Neo¢bularia Hechtel, 1965is subtle. Currently, both genera are distinguished essen-tially by their skeletal arrangement. Neo¢bularia has arather uniform skeletal architecture with reticulate choa-nosomal skeleton. Biemna has a skeleton ranging from hali-chondroid-reticulate to hymedesmioid with sub-renieroidreticulate and plumose examples. Four species ofNeo¢bularia have been described from Tropical AtlanticandWest Paci¢c locations; Biemna occur in all oceans in alarge depth range (Hajdu & van Soest, 2002).

The new species has been assigned to the genus Biemnabecause of the presence of a plumo-reticulate skeleton,formed by bundles of strongyles surrounded by spongin,

with dichotomous rami¢cations. The principal di¡erentia-tion between the new species and the other known speciesof the genus is the presence of strongyles as the mainspicule type.

There are two other species, Californian B. rhadia deLaubenfels, 1930 and Cuban B. cribaria (Alcolado &Gotera, 1986) in which strongylote forms may also bepresent. Biemna rhadia in addition to styli has strongyles,rhaphides and three size-classes of sigmas (de Laubenfels,1932). Biemna cribaria has stronglyles, rhaphides and twosize-classes of sigmas (Lehnert & van Soest, 1999). InBiemna strongylota sp. nov. the only megascleres found arestrongyles; microscleres are microxeas, raphides and twoforms of sigmas. In addition to this, it is necessary topoint out the presence in our specimens of some strongylesthat get thinner in one of their ends, giving an appearanceof round-pointed styles. In addition to this, in our speci-mens some strongyles get thinner at one tip, giving anappearance of rounded styles.

We are particularly grateful to Dr Rob van Soest from theZoological Museum, University of Amsterdam (ZMA), for hisrecommendations and his many positive comments and ClareValentine from the Natural History Museum, London (BMNH)for thoughtful review of the manuscript.This work is part of the projects: Spanish Ministry of Science

andTechnology (REN2001-1074ANT; REN2003-01881/ANT).The useful comments by two anonymous referees are also

gratefully acknowledged.

REFERENCESAlcolado, P.M. & Gotera, G.G., 1986. Nuevas adiciones a lafauna de por|¤ feros de Cuba. Poeyana, Instituto de Zoolog|¤ a.

Academia de Ciencias de Cuba, 331, 1^19.Beliaev, G.M. & Ushakov, P.V., 1957. Certain regularities inthe quantitative distribution of the bottom fauna inAntarctic waters. American Institute of Biological Sciences, 112,116^119.

Boury-Esnault, N. & Van Beveren, M., 1982. Les de¤ mospongesdu plateau continental de Kerguelen-Heard. Comite¤ National

Franc� ais des Recherches Antarctiques, 52, 1^175.Burton, M., 1932. Sponges. Discovery Reports, 6, 237^392.



Table 1. Antarctic species of Biemna.

Megascleres (mm) Microscleres (mm)

Distributiondepth (m)Species Reference Habitus Styles Strongyles Sigmas Microxeas Raphides

B. chilensis Thiele, 1905 Palmato-digitate

950�25 I. 46^55II. 18

220^240 Calbuco

Desqueyroux, 1972 Rounded orirregularlydigitated

814^1046�11^33 22^85 160^398 Calbuco(191)

Koltun, 1976 1500 500 MacRobertson Land;Kemp Land;Enderby Land(300^603)

Boury-Esnault &Van Beveren, 1982

487^975�13^26 I. 60^82�3^3.5II. 17^34

318^364 Kerguelen(95)

B. macrorhaphis Hentschel, 1914 Spherical 664^1016�25^29 25^85�2.7 360^424�1 St Gauss(385)

B. strongylota This work Stemmed 400^640�19^30 I. 35^100�2II. 10^22�1

58^86�2 130^238 Gerlache Strait(656)

Cristobo, F.J., Urgorri, V., Solorzano, M.R. & R|¤ os, P., 1993.Me¤ todos de recogida, estudio y conservacio¤ n de las coleccionesde por|¤ feros. In International Symposium & FirstWorld Congress on

Preservation and Conservation of Natural History Collections, Madrid

10^15 May 1992 (ed. F. Palacios et al.), 2, pp. 277^287. Madrid:Direccio¤ n General de Bellas Artes y Archivos. Ministerio deCultura.

Desqueyroux, R., 1972. Demospongiae (Porifera) de la costa deChile. Gayana, Instituto Central de Biolog|¤ a, 20, 3^71.

Hajdu, E. & Soest, R.W.M. van, 2002. Family DesmacellidaeRidley & Dendy, 1886. In Systema Porifera: a guide to the classi¢ca-

tion of sponges (ed. J.N.A. Hooper and R.W.M. van Soest),pp. 642^650. NewYork: Kluwer Academic/Plenum Publishers.

Hallman, E.F., 1916. A revision of the genera with microscleresincluded, or provisionally included, in the family Axinellidae;with descriptions of some Australian species. Part II. Proceedingsof the Linnean Society of New SouthWales, 41(163), 495^552.

Hentschel, E., 1914. Monaxone Kieselschwa« mme undHornschwa« mme der deutschen Su« dpolar Expedition. 1901^1903. Deutschen Su« dpolar Expedition Zoology, 7, 37^141.

Hooper, J.N.A. & Soest, R.W.M. van, ed., 2002. Systema Porifera:a guide to the classi¢cation of sponges. NewYork: Kluwer Academic/Plenum Publishers.

Koltun, V.M., 1976. Porifera. Part I: Antarctic sponges. BritishAustralian New Zealand Antarctic Research Expedition 1929^1931

Reports Series B (Zoology and Botany), IX(4), 147^198.Laubenfels, M.W. de, 1930. The sponges of California. (Abstractsof dissertations for the degree of doctor of philosophy.) StanfordUniversity Bulletin, (5) 5 (98), 24^29.

Laubenfels, M.W. de, 1932. The marine and fresh-water spongesof California. Proceedings of the United States National Museum, 81(2927), 1^140.

Lehnert, H. & Soest, R.W.M. van, 1999. More north Jamaicadeep fore-reef sponges. Beaufortia, 49(12), 141^169.

Ru« tzler, K., 1978. Sponges on coral reef. In Coral reefs: research

methods (ed. D.R. Stoddart and R.E. Johanness), pp. 81^120.Paris: Unesco.

Sara¤ , M., Balduzzi, A., Barbieri, M., Bavestrello, G. & Burlando,B., 1992. Biogeographic traits and checklist of Antarcticdemosponges. Polar Biology, 12, 559^585.

Thiele, J., 1905. Die Kiesel und Hornschwa« mme der SammlungPlate. Zoologische. Jahrbu« cher, 6, 407^495.

Submitted 30 December 2005. Accepted 1 June 2006.



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