Deep-Sea Research II 58 (2011) 58–67

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Deep-Sea Research II

0967-06

doi:10.1

n Corr

E-m

journal homepage: www.elsevier.com/locate/dsr2

Calcareous sponges from abyssal and bathyal depthsin the Weddell Sea, Antarctica

Hans Tore Rapp a, Dorte Janussen b,n, Ole S. Tendal c

a Centre for Geobiology and Department of Biology, University of Bergen, PO Box 7800, N-5020 Bergen, Norwayb Sektion Marine Evertebraten I, Forschungsinstitut und Naturmuseum Senckenberg, Senckenberganlage 25, D-60325 Frankfurt am Main, Germanyc Zoological Museum, University of Copenhagen, Universitetsparken 15, København Ø, DK-2100 København

a r t i c l e i n f o

Article history:

Received 18 May 2010

Accepted 18 May 2010Available online 1 June 2010

Keywords:

Antarctica

Weddell Sea

Deep-sea

ANDEEP Porifera

Calcarea

Ascaltis

Clathrina

Leucetta

Breitfussia

Leucosolenia

New species

45/$ - see front matter & 2010 Elsevier Ltd. A

016/j.dsr2.2010.05.022

esponding author. Tel.: +49 96 7542 1306; fa

ail address: dorte.janussen@senckenberg.de (

a b s t r a c t

Calcareous sponges have traditionally been regarded as shallow-water organisms, a persistent myth

created by Hentschel (1925), partly supported by the problematic question of calcareous skeletal

secretion under high partial CO2-pressure below the CCD in the abyss. Up to now, only few species

world-wide of the sponge class Calcarea have been described from depths below 2000 m. By far, the

largest number of records of Antarctic Calcarea is known from shelf areas between 50 and 400 m depth.

They have only been sporadically recorded on the lower shelf and the upper slope from depths between

570 and 850 m. From abyssal depths in the Antarctic there are no previous records of calcareous

sponges. It was therefore a big surprise when the first true deep-sea Calcarea from the Antarctic were

collected at depths between 1120 and 4400 m during the ANDEEP I, II and III expeditions (Janussen

et al., 2006). To date, five calcareous sponge species have been found, including three species new to

science. The three new species belong to the genera Ascaltis, Clathrina and Leucetta. Although calcareous

sponges are rare in the Antarctic deep sea, they seem to constitute a constant component of the fauna.

Antarctic Calcarea shows all the characteristics of need for revision and further collection and

investigation. Still, many new species are likely to be discovered in the Antarctic deep-sea.

& 2010 Elsevier Ltd. All rights reserved.

1. Introduction

In his famous chapter on sponges in Handbuch der Zoologiefrom 1925 Ernst Hentschel by oversight or forgetfulness created amyth: ‘‘Ihrer Tiefenverbreitung nach mussen die Calcarea alsausgepragte Flachwasserschwamme bezeichnet werden. y Unter700 m sind keine mehr sicher nachgewiesen.’’ (‘‘According to theirdepth distribution the Calcarea must be considered distinctshallow water sponges y.below 700 m none have been reportedwith certainty.’’ Own translation.) His authority was such thatthese statements since then have been accepted and repeated incountless papers, textbooks and handbooks. However, already athis time reports existed on several species of calcareous spongestaken both in the bathyal and abyssal zones of the North Atlantic(Carter, 1876: 805 m; Polejaeff, 1883: 843 m; Hansen, 1885:1403–2222 m; Topsent, 1892: 861, 1934: 1250 m). Comparativelyfew abyssal finds are from outside the North Atlantic (e.g. Koltun,1970), none of which are from the Southern Ocean.

Regarded as a fauna element of a larger geographic region,Antarctic Calcarea shows all the characteristics of need for

ll rights reserved.

x: +49 69 746238.

D. Janussen).

revision and further collection and investigation. Descriptionsand records have been published from scattered locations over aspan of more than 100 years and in several languages, reflectingscientific traditions and philosophy of different times in a numberof countries. The basic samples from many expeditions were few,small and often only fragments. The reason is that mostcalcareous sponges are fragile and of modest size as comparedto the more robust hexactinellids and demosponges normallytotally dominating Antarctic catches, and in the mixed samplesthey are easily destroyed already in the net or on deck.Accordingly, most reports from Antarctic expeditions list onlyfew Calcarea, if any.

By far the largest number of records of Antarctic calcareoussponges is from shelf areas, between 50 and 400 m depth. Theyhave only been sporadically recorded on the upper slope, and notat all on the lower slope and at abyssal depths. The recordsbetween 400 and 1000 m depth are few: Tanita (1959) reportedone calcareous sponge from 570 m off Queen Maud Land (Atlanticsector). Koltun (1976) identified two species from 603 m offEnderby Land and 640 m off Adelie Land, both in the Indian Oceansector. Tendal found 8 species at 11 stations at depths from 400 to890 m off Coats Land in the eastern Weddell Sea (Tendalunpublished.; partly mentioned without depth indications inBarthel et al., 1997).

H.T. Rapp et al. / Deep-Sea Research II 58 (2011) 58–67 59

No recent review of the composition and distribution of thecalcareous sponge fauna of the Antarctic continent exists. Fromthe reports of the expeditions, each mostly working in a particulararea, it appears, however, that the two subclasses of the classCalcarea as well as the most important orders and many familiesare represented and show the circum Antarctic distributionpattern seen in most benthic groups (Topsent, 1902, 1908; Jenkin,1908; Dendy, 1918; Burton, 1929, 1932; Brøndsted, 1931; Tanita,1959; Koltun, 1976; Barthel et al., 1997). The number of Antarcticspecies is not yet settled, but our estimate based on literature andour new findings is that at least 50 Calcarea spp. exist in theAntarctic ocean (see Section 4).

The First purpose of the ANtarctic DEEP-sea benthos researchprogram, initiated by A. Brandt (University of Hamburg), was ataxonomic and molecular inventory of the deep, mainly theabyssal Weddell Sea, which until 2002 was very little investi-gated. During the recent ANDEEP expeditions, large scaletransects were investigated at depths from 1000 down to 5000m within the Weddell Sea and adjacent areas (Cape Basin—AtkaBay, Kapp Norwegia, central Weddell Sea, Powell Basin, Scotia Seaand Drake Passage). Investigations were performed by under-water video and different sampling gears, including Agassiz trawl(AGT), epibenthic sledge (EBS), multicorer (MUC) and large boxcorer (GKG). Most of them belong to typical deep-sea species ofthe Cladorhizidae (class Demospongiae), but some of these smallspecies belong to the class Calcarea. An overview of the firstresults of sponge research during the ANDEEP expeditions wasgiven by Janussen and Tendal (2007).

Fig. 1. Distribution of Calcarea collected during the ANDEEP expeditions (2002–

2005) in the Antarctic Weddell Sea. Stations are marked by asterisks¼ANDEEP II,

squares¼ANDEEP III (for details see Table 1).

2. Methods and material

Sampling was performed by Agassiz trawl (AGT) and epibenthicsledge (EBS). During the ANDEEP I–III expeditions, we used theimproved EBS which includes a suprabenthic net, originallydesigned by Brandt and Barthel (1995) to catch small crustaceansjust above the sediment surface. A major part of the smallestsponges caught by EBS were found in the suprabenthic net; thesevery small specimens have probably been whirled up by theturbulence created during the sledge deployment. The improved EBSwith two nets has thus proven to be a very efficient tool for catchingsmall and fragile benthic animals in good condition (see also Section4). The three species described here as new to science were found byD. Janussen, two species during the ANDEEP II Expedition (ANT-IX/4,28.02.–1.04.2002) in the Weddell Sea and the third one duringANDEEP III (ANT-XXII/3, 22.01–06.04.2005) (Table 1, Fig. 1). Furtherdetails concerning the collection sites are given in Janussen (2003,2006). Spicule preparations and thick handcut paraffin sections weremade using standard protocols (Rapp, 2006; Valderrama et al.,2009). For each species 30 spicules of each spicule category weremeasured using a micrometric ocular. In the text spiculemeasurements are given as minimum–(mean)–maximum lengthof actines � thickness at the base of the actine. For regular triactinesonly one actine from each spicule was measured, while in sagittaltri- and tetractines the unpaired actine and one of the paired actines

Table 1Station list for calcareans.

ANT-XIX/4, ANDEEP II, stat. Date Depth (m) Gear Pos. la

133-3 7.3.2002 1120 EBS 65120

134-3 8.3.2002 4060 AGT 65119

133-3 7.3.2002 1120 EBS 65120

ANT-XXII/3, ANDEEP III, stat.

121-11 15.3.2005 2666 EBS 63138

081-8 24.2.2005 4384 EBS 70132

in addition to the apical actine in tetractines. As long as thespecimens were big enough to allow preparation of sections, speciesof species represented with one specimen only were cut in halfalong the longitudinal axix after habitus photos were made and thedescription of outer morphology was completed. The material isdeposited in the Senckenberg Research Institutet and NaturalMuseum, Frankfurt am Main, Germany.

3. Results

The ANDEEP expeditions provided new insights into thehidden life of the deep Southern Ocean, including the first recordof calcareous sponges from the Antarctic deep-sea. Of thecalcarean sponges new to science presented in this study, onlyone (Leucetta weddelliana sp. nov.) was collected by Agassiz Trawl(AGT), whereas the others were discovered in the epibenthic sled(EBS) samples. This emphasized the value of the EBS, a tooldesigned for the collection of epi- and hyperbenthic macrofauna,such as small crustaceans, and of small sponge species which arecommon in the deep-sea.

t. Pos. long. Species

S 54114W SMF 10358 Clathrina broendstedi sp. nov. (2 specimens)

S 4815W SMF 10359 Leucetta weddelliana sp. nov.

S 54114W SMF 10360 Breitfussia chartacea

S 50137W SMF 10361 Ascaltis abyssus sp. nov.

S 14134W SMF10362 Leucosolenia sp.

H.T. Rapp et al. / Deep-Sea Research II 58 (2011) 58–6760

3.1. Taxonomic results

Diagnoses of higher taxa follow Borojevic et al. (2000, 2002)and Manuel et al. (2002).

Table 2Spicule measurements of Clathrina broendstedi sp. nov.

Spicule Length (lm) Width (lm) n

Min Max Mean s Mean s

HolotypeTriactines 85 192 156 724 11 71.2 30

ParatypeTriactines 120 210 178 721 10 70.8 30

3.1.1. Class Calcarea Bowerbank, 1864

Subclass Calcinea Bidder, 1898Order Clathrinida Hartman, 1958 emend.Family Clathrinidae Minchin, 1900Clathrinida with an essentially tubular organisation. The

skeleton is formed by tangential triactines, to which tripods,tetractines and diactines may be added. A continuous choano-derm lines all the internal cavities. Water crosses the wall throughpores, surrounded by porocytes. The young sponges have anolynthus form that grows through longitudinal median division,budding and anastomosis of individual tubes to form the largeunits, called the cormus. There is neither a common cortex nor awell-defined inhalant or exhalant aquiferous system.

Genus Clathrina Gray, 1867Type species: Clathrina clathrus (Schmidt, 1864).Diagnosis: Clathrinidae in which the choanoderm is flat or

rarely raised into conuli by the apical actines of the tetractines,but never forms true folds, at least when the sponge is in theextended state. The full-grown cormus comprises anastomosedtubes. The skeleton is composed of regular, equiangular andequiradiate triactines and/or tetractines, to which diactines and/or tripods may be added.

Clathrina broendstedi sp. nov.(Fig. 2, Table 2)Type locality: Weddell Sea, Antarctica. 1120 m.Material: Holotype: SMF 10358, Weddell Sea, Antarctica.

ANDEEP II, st. EBS133-3. 1120 m depth. Paratype: Incompletespecimen, 20 x 8 mm. ANDEEP II, st. EBS133-3. 1120 m depth.

Previous records: As Clathrina primordialis (Brøndsted, 1931pars).

Etymology: Named after the Danish spongologist H.V.Brøndsted for his work on calcareous sponges in the Antarctic.

Description: The cormus of the holotype is a rounded toglobular mass of wide, loosely and irregularly anastomosingtubes, measuring 4 mm in diameter. No water-collecting tubesare present. One single naked osculum is visible in the top of thecormus of the holotype. The sponge is attached to the substratumby several basipetally oriented tubes. The paratype is an irregularfragment of a larger sponge without any visible oscules,

Fig. 2. Clathrina broendstedi sp. nov.: (A) holotype, os¼osculum

measuring about 1.5 cm. The sponge is white in alcohol. Thecortical and atrial sides of the tubes are both smooth. The verythin walls (consisting of only 2–3 layers of tangentially arrangedspicules) make the sponge very soft and easily compressible.There is no special orientation of the actines in the different partsof the sponge.

Skeleton is composed of regular and equiactinal triactines ofone size class only (actines of holotype: 85-(156)-192�11 mm).Some slightly parasagittal spicules were also found, but they donot represent a separate spicule category. Actines are all straight,conical, and with slightly blunt ends.

Distribution: Weddell Sea, Antarctica.Remarks: The specimens investigated here are very similar to

the Leucosolenia primordialis reported from off Kaiser Wilhelm II-Land by Brøndsted (1931). However, C. primordialis sensu Klautauand Valentine (2003) has two categories of regular triactines. Ourmaterial has unusually large triactines when compared to otherClathrina species with only one category of triactines and bearsstrong similarities to the triactines found in the upper part of thecormus of Guancha pellucida Rapp, 2006. However, G. pellucida

always has parasagittal spicules in the lower part of the cormusand the peduncle (Rapp, 2006; Schander et al., 2010). C. broendstedi

is most similar to Clathrina helveola Worheide and Hooper, 1999,but while the actines are sharp and slightly undulated in C. helveola

they are slightly blunt and straight in C. broendstedi. There are alsostrong similarities with Clathrina wistariensis Worheide andHooper, 1999 when it comes to outer morphology and organisationof the cormus. However, while the spicules are cylindrical withblunt tips in C. wistariensis they are conical and slightly blunt inC. broendstedi. Another difference is that brown granules have beenobserved in the porocytes of C. wistariensis (Klautau and Valentine,2003) while no such granules are present in C. broendstedi. Thismaterial of C. broendstedi was previously reported as Clathrina sp. inJanussen et al. (2003).

(scale bar 2 mm); (B) regular triactine (scale bar 75 mm).

Table 3Spicule measurements of Ascaltis abyssus sp. nov.

Spicule Length (lm) Width (lm) n

Min Max Mean s Mean s

HolotypeLarge triactines 209 331 279 725.5 14.1 71.5 40

Small triactines 124 264 216 737.7 9.6 71.4 40

H.T. Rapp et al. / Deep-Sea Research II 58 (2011) 58–67 61

3.1.2. Family Leucascidae Dendy, 1892

Clathrinida with a body differentiated into a cortex and achoanosome whose organisation is reminiscent of a clathroidcormus composed of anastomosed tubes. The cortex contains aspecific skeleton, composed of large triactines and/or tetractines.Choanocyte chambers are tubular, often highly ramified andanastomosed. The choanoskeleton is restricted to the wallsof the choanocyte chambers, maintaining a distinctly tubularorganisation.

Genus Ascaltis Haeckel, 1872Type species: Ascaltis lamarcki Haeckel, 1872: 60–61, plate 9

Fig. 5, plate 10 Fig. 4A–D.Diagnosis: Leucascidae with a massive cormus composed of

ramified and anastomosed tubes covered by a common cortex.The inhalant aquiferous system is represented by spaces delim-ited by the cortex and the walls of choanosomal tubes. Theexhalant aquiferous system is reduced to the osculum or to asecondary atrial cavity formed through the calyciform growth ofthe cormus.

Ascaltis abyssus sp. nov.(Fig. 3, Table 3)Type locality: Weddell Sea, Antarctica at 63138S50137, 2666 mHolotype: SMF 10361, ANDEEP III, st 121-11. 15.03.2005.Etymology: Named from the habitat of the holotype, the

Antarctic abyssal plains.Previous records: Leucosolenia lamarcki (Brøndsted, 1931) pars?Other material examined: MNHN. A slide of the type of A.

lamarcki (the Haeckel slide collection in Paris). ZIL. A. lamarcki,Roscoff.

Description: The cormus is sack-shaped, globular, and com-posed of ramified and anastomosed tubes, covered by a very thincommon cortex. There is a large central pseudoatrium and a verythin choanosome. The exhalant aquiferous system is onlycomposed of a large normal tube or cavity that ends in one largeosculum. Consistency is very delicate and soft. The colour isgreyish white. Cormus of holotype 10 mm in diameter.

The skeleton is composed of two categories of regulartriactines. The larger triactines (209-(279)-331�14.1 mm) aremainly found in the outer part of the cortex, and are easily visibleon the surface. Small triactines (124-(216)-264�9.6 mm) aremainly found in the choanosome. All actines are cylindrical andsharply pointed.

Distribution: Weddell Sea, Antarctic.Remarks: Ascaltis lamarcki has traditionally been regarded as a

morphologically variable species with a very wide distribution.However, A. lamarcki probably represents a complex of species, allwith a more restricted distribution. The holotype of A. lamarcki

Fig. 3. Ascaltis abyssus sp. nov.: (A) holotype (scale bar 2 mm); (B

possess both tri- and tetractines. We have studied the type, andHaeckel’s original description including spicule composition wasconfirmed. Even though samples were taken from different partsof our A. abyssus no tetractines could be found. It has previouslybeen shown that A. lamarcki may have very low numbers oftetractines and with a less distinct cortical membrane thanoriginally described by Haeckel (1872) (Borojevic and Boury-Esnault, 1987), but other Ascaltis with triactines only have neverbeen reported. For further discussion on Ascaltis confer Manuelet al. (2002) and Rapp (2004).

3.1.3. Family Leucettidae Laubenfels, 1936 (sensu Borojevic, 1968)

Clathrinidae with a solid body. The aquiferous system isalways leuconoid. The choanoskeleton is well-developed, in theform of a regular network composed of triactines and/ortetractines. The cortex is thin and composed of spicules similarto those of the choanoskeleton.

Genus Leucetta Haeckel, 1872Type species: Leucetta primigenia Haeckel, 1872.Diagnosis: Leucettidae with a homogenous organisation of the

wall and a typical leuconoid aquiferous system. There is neither aclear distinction between the cortex and the choanoskeleton, northe presence of a distinct layer of subcortical inhalant cavities.The atrium is frequently reduced to a system of exhalant canalsthat open directly into the osculum.

Leucetta weddelliana sp. nov.(Fig. 4, Table 4)Type locality: Weddell Sea, Antarctica, ANDEEP II, st. AGT 134/

3, 8.03.2002 at 651190S, 48150W, 4060 m.Holotype: SMF 10359. Weddell Sea.Etymology: Named after the type locality.Additional material examined: BMNH 25.11.1.35a. Pericharax

carteri var. homorrhaphis (Polejaeff, 1883). Challenger collection.Tristan da Cunha. BMNH 07.8.6.65a. Leucandra primigenia var.leptoraphis (Jenkin, 1908). Antarctic. Discovery Collection. BMNH10.2.7.1a. Leucandra microrhaphis Haeckel, 1872. Antarctic. Belgica

) regular triactines of two size categories (scale bar 100 mm).

Fig. 4. Leucetta weddelliana sp. nov.: (A) holotype, os¼osculum (scale bar 5 mm); (B) regular triactines covering the observed size range (scale bar 150 mm); (C) cross

section through the atrial wall. atri¼atrial skeleton of tangential triactines. cho¼choanosome (scale bar 150 mm); (D) cross section in the middle part of the sponge.

ca¼canal in the choanosome, cx¼cortical skeleton. scs¼subcortical spaces (scale bar 200 mm) and (E) longitudinal section through a canal in the choanosome (scale bar

150 mm).

Table 4Spicule measurements of Leucetta weddelliana sp. nov.

Spicule Length (lm) Width (lm) n

Min Max Mean s Mean s

Triactines 121 287 214 763 13.5 72 30

H.T. Rapp et al. / Deep-Sea Research II 58 (2011) 58–6762

Expedition. BMNH 84.4.22.56-7a. Pericharax carteri var. hetero-

rhaphis (Polejaeff, 1883). Challenger collection. BMNH 33.7.20.28.Leucetta maquariensis Dendy, 1918, South Georgia.

Description: The holotype is barrel-shaped; it has a thick wallwith a large atrium, and is 35 mm long and approximately 10 mmin diameter in the middle part, a bit broader at the base. Thesingle apical osculum is about 3 mm wide, naked, and onlysurrounded by a thin membrane. The colour is grey both in lifeand in ethanol. There are no anchoring spicules to attach thesponge to the substrate, but the base is rounded and there is adistinct line approximately 7–8 mm above the base indicating theboundary between the sponge and the surface of the softsediment. The outer surface is smooth with only some rays of

the cortical triactines irregularly protruding through the surface.Some subcortical cavities are present, but they are not supportedby a special skeleton. Aquiferous channels are irregularly ar-ranged in the choanosome, but several channels merge to openinto the central atrium. The atrial wall is folded into shallowridges and grooves.

Skeleton composed of regular and equiactinal triactines ofvariable sizes ranging from 121 to 287 mm in length, withoutdefined size categories ((121-214)-287�13.5 mm). Actines areslightly conical with sharp ends. There are no distinct sizecategories of spicules.

The skeleton is confused with no special organisation of thespicules. However, the actines of cortical triactines are slightlylonger and thicker than the choanosomal ones, and are arrangedin 2–3 layers parallel to the surface.

Distribution: Weddell Sea, Antarctica.Remarks: Five species of Leucetta have previously been

reported from Antarctic and sub-Antarctic waters, namely L.

antarctica Dendy, 1918; L. apicalis Brøndsted, 1931; L leptoraphis

(Jenkin, 1908); L. microraphis Haeckel, 1872 and L. pyriformis

Dendy (1913), but none of them have the small spicule size as ourL. weddelliana. sp. nov. In addition they have at least two distinct

Table 5Spicule measurements of Leucosolenia sp.

Spicule Length (lm) Width (lm) n

H.T. Rapp et al. / Deep-Sea Research II 58 (2011) 58–67 63

categories of spicules while our L. weddelliana has only onecategory. Our record is by far the deepest observation of anyLeucettidae.

The relationships between the genera Leucetta and Pericharax

have been debated and species have been moving back and forthbetween the two genera. They have traditionally been separatedby the presence of a large central atrium and specializedsubcortical inhalant cavities in Pericharax and the lack of thesecharacters in Leucetta. Recent work (e.g. Valderrama et al., 2009)has shown that presence of a developed atrium is highly variablewithin species, and a wide atrium is often present also in someLeucetta. On the other hand, subcortical inhalant cavities are oftenpoorly developed within species of ‘‘Pericharax’’ and/or thecavities lack a specialized skeleton. The validity of the distinctionof these two genera is therefore questioned, and due to senioritywe here use the name Leucetta for our new species.

Min Max Mean s Mean s

Triactines, sagittalPaired actines 163.3 346.9 291 750.6 26.1 78.3 15

Unpaired actine 163.3 551 389.9 7109.5 22.6 73.3 15

Tetractines, sagittalPaired actines 224.5 306.3 273.8 729.9 21.5 75.4 6

Unpaired actine 214.3 428.6 350.3 778.9 19.9 73.6 6

Apical actine 26 33.8 24.2 74.7 9.3 72.0 6

Large diactines 236 319 273 726.7 3.0 70.6 10

Small diactines 117 148 129 711.7 4.3 70.7 30

3.1.4. Subclass Calcaronea Bidder, 1898

Order Leucosolenida Hartman, 1958Family Leucosoleniidae Minchin, 1900Leucosolenida with a cormus composed of frequently

branched, but rarely anastomosed, asconoid tubes, and with acontinuous choanoderm that lines all the internal cavities of thesponge. There is neither a common cortex covering the cormus,nor a delimited inhalant or exhalant aquiferous system.

Genus Leucosolenia Bowerbank, 1864

Fig. 5. Leucosolenia sp.: (A) fixed specimen (scale bar 1.2 mm); (B) sagittal tetractines

(D) sagittal triactines (scale bar 200 mm); (E) left: diactine from the oscular fringe. Rig

lanceolated and pointed ends of small diactine (scale bar 20 mm).

Type species: Leucosolenia botryoides (Ellis and Solander,1786)

Diagnosis: Leucosoleniidae in which the skeleton can consist ofdiactines, triactines and/or tetractines. There is no reinforcedexternal layer on the tubes.

Leucosolenia sp.(Fig. 5, Table 5)Material examined: SMF 10359, Weddell Sea, Antarctica,

ANDEEP III st. 81/1, 24.02.2005 at 701320S, 141340W, 4384 m(1 specimen).

(scale bar 200 mm); (C) cone shaped apical actine of tetractines (scale bar 10 mm);

ht: lanceolated diactine from the sponge wall (scale bar 40 mm) and (F) detail of

H.T. Rapp et al. / Deep-Sea Research II 58 (2011) 58–6764

Description: The material consists of a single specimen. It is aslender and tubular sponge measuring approximately 4 mm longand 1.5 mm wide and with a narrow base. The surface is slightlyhispid. Spicules are sagittal triactines (paired actines 163-(291)-346�26.1 mm, unpaired actine 163-(389)-551�22.6 mm) andsagittal tetractines with short apical actines (paired actines 224-(273)-306�21.5 mm, unpaired actine 214-(350)-428�19.9 mm,apical actine 26-(24)-33x9.3 mm) and two types of diactines (236-(273)-319�3 mm and 117-(129)-148�4.3 mm). Tri- and tetra-ctines are arranged with their unpaired actine oriented towardsthe base of the sponge. The smaller diactines are penetrating thesurface of the sponge while the longer diactines are found in theoscular fringe. All spicule rays are cylindrical and sharp to slightlyblunted except the apical actine which is sharply pointed.

Distribution: Only known from this locality.Remarks: Due to the very small size of our specimen there was

not enough material to make sections and proper spicule slides.Therefore only a small number of spicules of each category couldbe measured. The sponge bears strong similarities to Leucosolenia

minchini Jenkin, 1908 in terms of spicule categories and shape ofspicules. However, the spicules are approximately three timesbigger than in L. minchini, and much bigger than in any otherknown species of Leucosolenia. Even though this specimen mostlikely represents a new species we consider the materialinsufficient to give a full description and name.

Our specimen represents the deepest record of a Leucosolenia

and the second deepest record of any calcareous sponge.

3.1.5. Family Jenkinidae Borojevic et al., 2000

Leucosolenida with a syconoid, sylleibid or leuconoid organi-sation. The thin wall surrounding the large atrial cavity issupported by tangential atrial and cortical skeletons, andessentially an inarticulated choanoskeleton consisting of unpairedactines of the subatrial triactines and/or tetractines, and occa-sionally with small radial diactines. The proximal part of the largeradial diactines that protrude from the external surface, or thetangential triactines scattered irregularly in the cortex, may alsoform the choanoderm. Large cortical tetractines or subcorticalpseudosagittal triactines are not present.

Genus Breitfussia Borojevic et al., 2000Type species: Ebnerella schulzei Breitfuss, 1896Diagnosis: Jenkinidae with a simple tubular body and syconoid

organisation. The choanoskeleton is reduced to the unpairedactines of the subatrial triactines, and occasionally contains theproximal part of radial diactines.

Breitfussia chartacea (Jenkin, 1908)(Fig. 6, Table 6)Original description: Dermatreton chartaceum Jenkin, 1908: 22.Type locality: ‘‘Winter Quarters’’ of the National Antarctic

Expedition (‘‘Discovery’’) 1901–1904 in the Ross Sea, Antarctica atapproximately 400 m depth.

Material examined: SMF 10360—ANT-XIX/4, ANDEEP II station133-3 (1 specimen), 1120 m.

Additional material examined: Breitfussia schulzei (Breitfuss,1896) from the East Greenland Expedition, Forsblad fjord, 1900,100–170 m. Specimens of a new species of Breitfussia collectedjust south of Iceland in the north Atlantic at 2300 m depth (Rappunpublished data, the BIOICE collections) were also used forcomparison.

Description: Sponge solitary, erect and cylindrical, broadest atmid-height. One apical osculum without oscular fringe. Surfaceeven but echinated by stout projecting diactines. Texture fragile.The sponge wall is very thin, measuring only about 300 mm. Theatrium is wide, and the sponge measures 5 mm in height and2.5 mm in width (the basal part is missing). Aquiferous system is

syconoid with oval choanocyte chambers. Colour in ethanolgreyish white.

The spicule rays are round to slightly conical in cross section.Cortex and subcortical layer composed of one type of subregularto sagittal triactines arranged in parallel to the surface wheresome of the paired actines somewhat pointing inwards perpendi-cularly to the outer surface actines (88-(150)-218�14.1 mm). Thesubatrial layer also consists of sagittal triactines with the longunpaired actine in centrifugal direction (paired actines 122-(182)-224�16.7 mm, unpaired actine 182-(245)-439�16.6 mm). Atrialskeleton composed of sagittal tetractines (paired actines 42-(87)-106�8.7 mm, unpaired actine 65-(154)-187�7.6 mm, apicalactine 64-(83)-105�7.8 mm) and some more rare triactinessimilar to the tetractines (paired actines 70-(103)-156�9.7 mm,unpaired actine 106-(160)-231�9.7 mm). The long, smooth andsharply pointed apical actines of the tetractines are protrudinginto the atrial cavity. The choanosomal layer contains somescattered sagittal triactines similar to the atrial triactines. Thecortex is penetrated by scattered diactines (214-(310)-408�12.1 mm) and the unpaired actine of subatrial triactines.Trichoxea (up to 130�2.2 mm) are scattered in all parts of thesponge but are particularly common in the atrial wall.

Distribution: Ross- and Weddell seas, Antarctica.The species has been reported from several shallow-water

localities off Kaiser Wilhelm II-Land in the Antarctic (Brøndsted,1931).

Remarks: The cortex in our specimen is thicker and composedof a bit stronger spicules than reported by Jenkin (1908). Thetrichoxeas are easily broken and the maximum value given inTable 6 is most likely an underestimate.

4. Discussion

Although the traditional main tool for sponge collection fromdeep water is some kind of trawl, we have the experience fromexpeditions and cruises during the last 25 years in differentparts of the world, that the EBS and other gears with finemesh sizes have proven to be very important for sponges smallerthan 0.5 cm, unlikely to be caught by the regular trawl (e.g. Ilanet al., 2003).

It is a remarkable fact that the former collections comprisinglarge numbers of specimens and species of Antarctic calcareoussponges originate from restricted areas where repeated samplinghas been done over a longer period of time. One example is thematerial from ‘‘Winter Quarters’’ of the National AntarcticExpedition (‘‘Discovery’’) 1901–1904 in the Ross Sea, on the basisof which Jenkin (1908) described 23 species, 20 of them as new toscience. Another is the ‘‘Winterstation’’ collection of the DeutscheSudpolar-Expedition (‘‘Gauss’’) 1901–1903 off Kaiser Wilhelm II-Land, where Brøndsted (1931) found 29 species from the area, 14of them described as new. Brøndsted (l.c.) listed 50 nominalspecies to have been reported from the Antarctic shelf. Thereafter,the number of accepted species has been drastically falling.Burton (1929—the publication came after Brøndsted’s went toprint) reduced the number to 20, especially synonymizing speciesdescribed by Jenkin (1908). Later, in a globally covering catalogueof Calcarea species, Burton (1963) suggested a profound reductionin the number of species world-wide; according to this thenumber of Antarctic species would be 7. Although rejected bymost contemporary workers, the revision by Burton (l.c.) waspartly supported by Koltun (1970) who concluded that the actualnumber would be ‘‘more than 8’’. Recently, the pendulum hasswung to the other side, as Hooper and Wiedenmayer (1994)ignore the many synonymizations listing 44 species from theAustralian Antarctic Territory alone, and McClintock et al. (2005)

Table 6Spicule measurements of Breitfussia chartacea.

Spicule Length (lm) Width (lm) n

Min Max Mean s Mean s

Cortical and subcortical triactines 88 218 150 726.3 14.1 2.7 30

Choanosomal and atrial triactinesPaired actines 70 156 103 720.6 9.7 72.7 29

Unpaired actine 106 231 160 729.7 9.7 73.0 29

Subatrial triactinesPaired actines 122 224 182 728.5 16.7 73.6 13

Unpaired actine 182 439 245 760.1 16.6 74.3 13

Atrial tetractinesPaired actines 42 106 87 722.2 8.7 71.6 7

Unpaired actine 65 187 154 744.9 7.6 71.2 7

Apical actine 64 105 83 713.6 7.8 71.3 6

Diactines 214 408 310 768.5 12.1 73.2 6

Trichoxea – 130 – – 2.2 70.5 6

Fig. 6. Breitfussia chartacea: (A) upper half of the fixed specimen (scale bar 2 mm); (B) cross section of the sponge wall. Arrow head¼unpaired actine of subatrial triactine

extending through the entire choanosome and the outer cortex, cx¼cortex, atr¼atrium (scale bar 200 mm); (C) cross section of the sponge wall. ctr¼cortical triactines,

ap¼apical actine of atrial tetractines pointing into the atrium (scale bar 200 mm); (D) cross section of the sponge wall with a lanceolated diactine (di) crossing the cortex

(scale bar 100 mm); (E) spicules. di¼diactine, ctr¼cortical subregular triactine, satr¼sagittal subatrial triactine (scale bar 150 um); (F) atrial tetractines (scale bar 50 mm)

and (G) trichoxea (scale bar 5 mm).

H.T. Rapp et al. / Deep-Sea Research II 58 (2011) 58–67 65

Table 7Species richness of some Porifera taxa collected during ANDEEP I–III (Janussen et al., 2004; Janussen and Tendal, 2007).

Porifera taxon No. of species No. of species by EBS No. of species by AGT No. of species by EBS and AGT

Class/family Total spp. no. % of all (76) Porifera spp.

Calcarea 5 7 4 1 0

Hexactinellida 21 27 7 18 4

Demospongiae 49 65 19 37 7

Cladorhizidae 15 20 8 8 1

H.T. Rapp et al. / Deep-Sea Research II 58 (2011) 58–6766

accept 49 species from the whole Antarctic region. Manuel et al.(2002) point out that recent molecular investigations support thisview and place careful traditional taxonomy in a somewhatconservative light. Following the recent trend accepting almost allnominal species, the Calcarea of Antarctica can, according to ourconservative estimate, be expected to comprise at least 50described species (ca. 40 spp. on the shelf+slope and ca. 15 spp.in the abyssal deep-sea; a few of the spp. occur at both depthregimes). In biodiversity overviews their role is thus significantlychanged, from comprising about 2% of the known species in theAntarctic sponge fauna to more than 10%. It is noteworthy thatthis figure (50 spp.) does not include any Antarctic deep-seaCalcarea, which are up to present undescribed.

During the ANDEEP I–III expeditions, 5 calcarean species from5 different stations were collected, and all except Clathrina

broendstedi sp. nov. (2 specimens) were single individuals, 3 ofthese species were new to science and 4 have never been recordedin the Antarctic before. The 5 calcarean species belong to 5different genera and 5 families. They make up ca. 7 % of the total76 sponge species, but only 1.6% of the about 500 spongespecimens collected in total during ANDEEP I–III. Taken the verypatchy and isolated collections in the deep Weddell Sea, anygeneralisation concerning the distribution of Antarctic deep-seaCalcarea should be done with caution.

In terms of its potential for discovery of new Antarctic taxa, themost comparable Porifera group, is probably the demospongefamily Cladorhizidae. This is because most of the cladorhizidspecies are characterized by small body size and, similarly to thedeep-sea Calcarea are mainly caught by the EBS. Because deep-seasampling of the early expeditions were all done by trawl, not byEBS, both sponge groups are still largely undescribed from theAntarctic deep-sea. Also both deep-sea Calcarea and Cladorhizi-dae, have been previously overlooked in samples, mainly becauseof their unspectacular morphology, small body size, and the factthat they are fragile and easily fragmented. Future deep-seaexpeditions with similar focus on the Porifera like the ANDEEPcampaign will certainly bring about considerable numbers of newrecords of both taxa. Family Cladorhizidae in the collections ofANDEEP (2002–2005) is represented by 15 species, 36 specimens(+several fragments) caught at 15 AGT and/or EBS stations. TheSYSTCO and ANT-XXIII/8 expeditions, 2007–2008, providedadditionally 4 species and 3 specimens, respectively (Janussenand Plotkin, 2009). Compared to this wide distribution of theCladorhizidae, the Antarctic deep-sea Calcarea are represented sofar only by 5 species and 6 specimens, including fragments,collected at only 5 ANDEEP stations. Given the same stations andthe same gears applied, as well as the fact that the samples weresorted and investigated with the same scientific expertise, wehave no reason to doubt that these figures give the correctimpression of diversity and abundance of those two very differentsponge taxa. In other words, if a specialist looking for one taxon ofsponges in the catches, he or she cannot avoid finding also theother sponge group(s) if they are present. Whereas we find theANDEEP Cladorhizidae geographically widely distributedthroughout the deep Weddell Sea and with at least a few

specimens of one species at some stations, the Calcarea occuronly at 5 stations, and mostly with only one specimen of eachspecies and per station. In contrast, the taxon Hexactinellida,which is characterized by large individual sizes, is represented by21 species from almost all ANDEEP AGT-stations, where theyoften occur in considerable numbers (Janussen et al., 2004,Table 7).

If we furthermore compare our new deep-sea Calcareaoccurrences with the records of calcareous sponges from theAntarctic shelf according to literature, we find that roughly about1/10 of the known Antarctic calcarean species so far recorded arefrom the deep-sea. In the course of future Antarctic deep-searesearch, this number can be expected to steadily increase.

We thus find it reasonable to conclude that the Calcarea in thedeep Weddell Sea are fairly diverse, but rare in terms ofindividuals. Furthermore, that Calcarea are particularly rare inthe deep Southern Ocean and do not seem to thrive well in theAntarctic compared with other World oceans (e.g. the deep NorthAtlantic and Arctic Oceans, Rapp and Tendal, unpublished). Mostprobably, their poor representation in the Southern Ocean andespecially in the Antarctic deep-sea is due to the lack of adequatesuspended food particles for calcarean sponges, maybe combinedwith disadvantages as particularly high CO2 partial pressure (andcomparably shallow depth of the CCD boundary) in this cold Polarsea. This is indicated also by high diversities and wide distributionof the carnivorous Cladorhizidae and the pico-plankton feedingHexactinellida in this same region.

Acknowledgments

We thank the ANDEEP-SYSTCO initiator, Angelika Brandt, andthe Antarctic scientific community of for good cooperation, andthe captain and crew of RV ‘‘Polarstern’’ for their efficiencyand kindness. We are most grateful to Nina Therese Mikkelsenand Alexander Plotkin for their help during production of thefigures. The Zoological Institute of the Russian Academy ofSciences, St. Petersburg, Russia (ZIL) and the Museum nationald’Histoire naturelle, Paris (MNHN) are thanked for access tomaterial and slides of Ascaltis lamarcki, and The Natural HistoryMuseum, London (BMNH) is thanked for the loan of slides of anumber of Leucetta species. DJ acknowledges the DeutscheForschungsgemeinschaft for financial support to the Antarcticsponge research project (JA 1063/14-1) and SYNTHESYS forfinancing ZMUC (DK-TAF 4492) and (FR-TAF 5332). Parts of thisproject were supported by the Norwegian Research Council(project no. 158923/S40, to HTR) and by the CeDAMar TaxonomistExchange Program. This is ANDEEP-SYSTCO publication no. 126,and CAML publication #42.

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