THE NAUTILUS 122(4):228-235, 2008 Page 228 A new species of Sphaerium Scopoli, 1777, from southern Brazil Bivalvia: Sphaeriidae^ Maria Cristina Dreher Mansur Claus Meier-Brook Cristian Ituarte Av. Arlindo Pasqualini, 410 Sommergasse 10 Museo Argentine de Ciencias Naturales 91760-140 Porto Alegre, BRAZIL D-72119 Ammerbuch-Reusten Av. Angel Gallardo 470, C1405DJR, Buenos GERMANY [email protected] Aires ARGENTINA [email protected] ABSTRACT Sphaerium (S.) bohvien.se (Sturany, 1900), from the highlands of Bolivia and from a lake in Junin, Peru. He Sphaerium cambaraense new species is described based on examined also material ofdiis species collected by Sioli samples collected in the beginning of tlae summer near the in the regions of the rivers Maue-Agu and Tapajos, headwaters ofTaquari River (Jacui River Basin) on thebasaltic tributaries of the Amazon River, which constitutes the plateauofsouthern Brazil. This istliefirstrecordfordiegenus Sphaerium in Brazil and in South America outside the Andes. first record of Sphaerium for Brazil. According to Kui- Sphaerium cambaraense is characterized by a relatively large per and Hinz (1984), S. bohviense is ajunior s)iionym of and solidshell, ahigh triangularshell oudine and asolidhinge S. forbesi. plate. Compared with Sphaerium forbesi (Pliilippi, 1869), The record oi Sphaerium obscivationis by Mansur S. cambaraense has a more strongly triangular shell outline et al. (1991) for Mirim Lagoon in southern Brazil is a and beaks not prominent. Sphaerium lauricochae (Philippi, misidentification, as that species is not a Sphaerium. 1869), another similar species from Bolixda, Chile, and Peru, According to the revision bv Ituarte (1995), Pisidium has amore roundedshell outline. observationis Pilsbry, 1911. onK occurs in the southern Additional Keijicords: Freshwater, Rio Grande do Sul, South Argentina, not in Brazil. America Sphaerium cambaraense new species is the fifdi Sphaerium species from South America and the first spe- cies ofdie genus described from southern Brazil, in the highlands near the Adantic Oceair, a location geographi- INTRODUCTION callyverv distant from die Andes and Amazon River According to Dreher-Mansur and Meier-Brook (2000), MATERIALS AND METHODS the familySphaeriidae is representedbytwosubfamilies: Euperinae, inchading tlie genera Eiipera Bourguignat, Specimens were collected with a plastic sieve with mesh 1854, and Bijssanodonta d'Orbigny, 1846; and Sph- size of about 0.8 mm. Specimens were sorted from the aeriinae with diree genera, Sphaerium ScopoU, 1777, sediment widr fine feather tweezers; anesthetized in Musculium Link, 1807, andPisidium Pfeiffer, 1821. small vials containing water witir mendiol crystals, fixed Four species oftlie genus Sphaerium are known from ina5% formalinsolutionfor24hours, rinsedfor24hours South America: Sphaerium aequatoriale Clessin, 1879, in tap water and presei-ved in 70% ethanol. Soft parts of from Ecuador (Kuiper and Hinz, 1984); S.forbesi (Phi- specimensforscanningelectronmicroscopy(SEM)were lippi, 1869) recorded from Peru and Bolivia (Haas, removed with tweezers, shells cleaned with a soft and 1949), from Bolivia (Haas, 1955), from Colombia, Peru, fine brush and rinsed several times in distilled water Bolivian Andes (Kuiper and Hinz, 1984), and Chile Dried shells were glued on stubs with light-silver glue (Ituarte, 1995); S. lauricochae (Philippi, 1869), from (Porolon Equipment, Herts) or metallic adliesive tape PeiTj, Bolivia and Chile (Kuiper and Hinz, 1984), and (T066 Silvertape 9 mm, Hert-Scotch), coatedwidi gold, Chile (Ituarte, 1995); S. titicacense (Pilsbiy, 1924), from andobsei'ved eitherin aCambridge Stereoscan 250 Mk2 Peru and Bolivia (Kuiper and Hinz, 1984). According to or Philips scanning electron microscopes. Shell micro- these authors, they are concentrated in the Central structure was studied by fracturing shells at the middle Andes from Ecuador to North Chile including high- ofdie height, parallel to commarginal ridges. Terminolo- altitude Bolivia, at 2000 to 4700 m altitude; varying in gy for shell microstructure follows Dyduch-Falniowska size between 3 and 12.5 min. Haas (1949) reports (1983) and Dreher-Mansur and Meier-Brook (2000). M. C. D. Mansur et al. 20()S Page 229 Stonuifli nomenclatuic lollows I'urclion (1958, 1960). gently curved below middle of total height, without The shape indices, height index [I = H/L] and convexity marked angle. Posterior end slightly truncated, oblique index [Ci = W/H], were calculated according to the ci"i- (Figures 1, 2). Ventral margin long and evenly cui-ved. teria followedbyItuarte (1996). Shell surface silky, glossy, witli very fine irregularly .•\bbre\iations use in the text are: MACN, Museo distributed radial lines, weaker on beaks and irregular Argentiuo de Ciencias Naturales, Buenos Aires; MCN, conimarginal, sometimes coarse, striae (12 or more per mm Museu de Ciencias Naturals, Fundayao Zoobotanica do 0.5 in the middle ofthe shell (Figure 3). Outer shell Rio Grande do Sul, Porto Alegre; MCP, Museu de Cien- surface lightyellowish brown; pale browni at beaks, more cias e Tecnologia da Pontificia Universidade Catolica, ventrally grayish brown with complete or incomplete Rio Grande do Sul, Porto .-\legre, Brazil. yellow concentric bands rtmning from anterior to poste- rior margins; a large yellow band near ventral margin. Genus Sphacriutn Scopoli, 1777 Beaks without marked embryonic cap. Inner shell sur- Spliaeiiiim cambaraensc new species face white, grayish at muscle scars. Beaks slightly proso- (Figiu-es 1-20) gyrous, low and wide, shghtly raised above dorsal Diagnosis Distinguished b\' the relatixelv large and margin, subcentrally located (Figures 1, 2, 6, 7). Hinge plate strikingly cuwed, solid, broad, reaching solid shell with trapezoidal tending to triangular shell mm mm 0.5 width in middle region in specimens of 11 outline, low andwide beaks, subcentrallylocated, without length, slightK' narrower at level ofcardinal teeth. Hinge marked nepionic cap, and broad and solid hinge plate. linearched,paiticularlybelowcardinalteeth (Figm'cs6-9). Description: Shell: Solid, relatixely large (maximum Cardinal teedi strong, close to dorsal margin. Right obsencd L: 11.22 mm), slightl)' convex (Ci = 53±5). cai"dinal toodi, C3, short, strongly cui-ved, posterior end Shell oudine high (I = 85±2), trapezoidal tending to enlargedin agroovedcup (Figure 10). Left cardinalteeth: tiiangidar Dorsal margin has pronounced cui-ve. Anteri- outer cardinal tooth, C4, diin, strikingly oblique, located or and posterior margins gradually descending and immediately behind C2, anterior end slightly overlapping Figures 1-5. Sphaeriiim cambaraense new species. 1, 2. Holotype MCP Mol. Outer view ofleft and right valves. 3. Detail of outershell surface. 4, 5. Inner shell surface, detail ofpores. Scale bars: 1, 2 = 4 mm; .3 = 400 |.uii; 4 = 4 (im; 5 = 40 i^m. Page 230 THE NAUTILUS, Vol. 122, No. 4 Figures 6-11. Spliewnuui cambaracnse new species. Paiatype (MACN-ln .37()(i3). 6. Inner N-iew ot right valve. 7. Inner view of right valve. 8. Hinge of right valve. 9. Hinge ofleft valve. 10. Detail ofright cardinal tooth (C3) and ligament. 11. Detail ofleft cardinal teeth (C2 and C4) and ligament. Scale bars: 6, 7 = 2 mm; 8, 9 =1 nnii: 10, 11 = 500 |im. C2; inner cardinal tootli, C2, short, high, columnar, deeply Shell Microstructure: Inner shell surface perforated arched into a V-shape (Figure 11). Right lateral teetli by numerous pores (55/400 nm" to 1.3/160 nm") (Figiu'es .somewhat short, strong, with distal cusps (Figure 8); left 4, 5) representing the opening oftubuli that cross entire lateral teeth relatively long, strong, and high (Figure 9). calcai'eous pait of shell (showai in part in Figiu'e 12). Ligament internal but exteriorlyvisible, slightlyprotrud- Openings of pores on inner surlaee surrounded by a ed in larger.specimens (Figures 10, 11). funnel-shaped depression and m nionlli circled by a rini M. C. D. Mansiir ct ;il., 2(K).S Pase 231 [:"!«{fi5riW«»i IS'V'kl "N-^ KM^S^^r^ ^/4^^> i«--Ssv-ij^^Mr^ Figure 12. Sphucnuiu ciimbarafiisc newspecies. Shell iiiicrustructure iruiii a: penostracuiii (topi tot': the eiitlostracuiii (botloiii,) Inserts a-gare details of: a, periostracum; b, granularlayer; c, diagonal layer forming acomposite prismatic stnicture; d, diagonal la\er. crossed structure: e, diagonal layer forming a pseudo crossed lamellar stnictiire; f, palisade structure; g, diagonal layer and internalsurface ofthe endostracum (arrow). Scalebars: 12 = 50 |im; inserts: a-d = 4 |im; e = 20 \im; 1 = 10 |jm; g = 2 |im. Pa2;e 232 THE NAUTILUS, Vol. 122, No. 4 M. C. D. Mansur et al., 200S Pase 233 (Figure 4). Shell relatively thick reaching 200 j.im in on dorsal hood and right side such as short gastric shield central area (Figin'e 12). Shell structure consists ol' under dorsal hood: minor txqDhlosole and rejecting tract fne la\'ers: periostracum, granular laver, diagonal layer, beginning at right side after descending from dorsal palisade, diagonal la\er, and endostracuni. Below the hood; and an ele\ation slightlywrinkled between intesti- 2 pni thickperiostracum (Figure 12, a), agranular 10 |.ini nal groove and rejection tract; anterior fold absent. In- thick laxer appears (Figiu'e 12, b); grains concentrated testine opening associated to style sac in center offloor; in some points irregidarK' and sparseh' distributed, look- major tyj^hlosole arched in front with two expansions ing like cone-shaped bars arranged pei^pendicularly to that end respectively at left and right duct openings, not shell surface. These change into irregularly and com- penetrating in ducts, which allocates the stomach to pactK'arranged grains ofdifferent sizes. More internally, Tx-pe IV; left and right duct openings well developed shell structure changes gradualK' into a diagonal layer and ramified in three secondaiv ducts. (Figiu'e 12, c, d, e), where three different patterns may Intestine short and simple (Figiu'e IS), anterior part be distinguished: first (about 50 |am thick), composite associated to style sac, broad, descending straight to prismatic structure, showing vertical feather-like pattern floor of visceral mass; mid-intestine strikingly stretched (Figin-e 12, c); second (about 40 |im thick), occupies forming single loop; hindgut straight, ascending and die central part of shell, gradually changing into a bending towaril rectum that ends into an anal papilla. cross-lamellarstioictnre (Figure 12, d); thethird (appro.x- Nephridia of closed t\'pe; dorsal and outer lobes fused, imateh' 60 (im), resembles a pseudo crossed-lamellar impossible to distinguish in dorsalview (Figures 19, 20); stiTicture (Figure 12, e). Close to tlie inner shell surface external wall ofouter lobe ornamentedwidi many small, diere are one or tvvo palisade layers, narrow (each about rounded extrusions; nephridia in young specimens usu- 1 |,uu thick) (Figure 12, f). The palisade structure is ally ofopen i\rpe and v\dth separated lobes. Fimnel rela- followed bv a diagonal layer with lamellae oriented tively long and wide; pro.ximal loop with smooth walls in one direction (Figure 12, g): below, a veiy narrow forming three ascending rings then run backward up to la\-er, the endostracuni (1.0 to 1..5 \.im thick) (Figure 12, posterior adductor muscle, turning laterally in direction arrow1. to lateral k)op. Lateral loop straight, elongated, running Ax.woMV (Figures 13-20): Inner and outer demi- along outer side and partially covei'ed laterally b)' outer branchs well-developed, outer smaller demibranch lobe. Excretoiy sac sub-triangular, romided in front and reacliinghalfofheight ofinnerdemibranch (Figure 13). relatively small. No valve at the entering of the distal Brood sacs occupy anterodorsal part of inner denii- loop into excretoiy sac. branchs, embnos contained in sacs showed different Type Locality: Lajeado da Margarida (50''15.75' W, dUepx-teolosipxmednetvaellopsitanggese,mbdreynoostifnogunsdeqinuelnatrigaelst berxoaomdiinneg.d 29"0.87' S; 870-SSO m altitude) on'Camisa River, Antas mm River Basin, considered to be the headwaters of Taquari specimen (>11 lengtli). Largest, tertiaiy, brood sac contained two embi-yos (>1 mm length) (Figure 13); River, tlie main tributaiy of Jacui River, South Atlantic Brazilian Basin. secondaiysac located underlargest one, contained three or four small embryos. Primary sac attached lower on Type Material: Holotype MCN 38821; Paratypes: inner demibranch. (Specimens for this study were col- MCN 33919 (33 specimens), MCP 9109 (6 specimens), lected at the beginning of tlie Southern Hemisphere MACN-In 37063 (two specimens). 12 Jan. 1994. summer (Januan.-, 1994) and many of the specimens largerthan 9 mm showed brood sacs.) Anal andbranchi- Etymology: The specific epithet refers to the Cit)'and al openings extended in diverging short siphons, nearly Municipality ofCambara, close to the type locality. equal in size. Anal siphon wider at base and more stre- Distribution and Habitat: Known onlyfrom the type tched out (Figure 13). Two labial palps (Figure 13, 14) localit\'. The Miniicipalit\ ol Cambara is situated in on each side ofmouth, triangular-shaped in lateral view: northeastern Rio Grande do Sul State, Brazil, in the opposite contacting walls with 12 small folds, tapering highest part named Planalto Riograndense. From the toward distal ends. Mantle musculature (Figure 15) with physiographic point ofview, this region is characterized relatix'elv short siphonal retractors; inner radial mantle by a basaltic shield covered by low grass steppes and muscles arranged in eight to nine bundles (Figure 15). Araucaria Forest mixed with the southeastern limits Fan-shaped stomach (Figures 17, 18) bent to right of the Atlantic Forest. The altitude varies from 850 to side, laterally covered bv digestive gland. Dorsal hood 1050 m, and in the winter, temperatures fall below relativeh' short and left duct well developed. Stomach freezing andthere is the occasional snow. The rivers diat intemalK- (Figure 17) shows \'er\" simplified structures cross the region, flanked bv a low galleiy forest, ha\'e Figures 13-20. Sphacrium cambaraensc new species. Sclieniatic drawings olsoit anatomy. 13. Gross anatomy (left mantle lobe remo\ed'. 14. Folded surfacesofinnerandouterleftlabia! palps. 15. Outerviewofleftmantlelobeshowingtheinnerradial manrie muscfes. 16. Dorsal\iewofthestomach and digestivegland. 17. Floorofdiestomach afterremovingthe roof 18. Innerviewofdie organsinthe\iscerat mass. 19. Dorsalviewofnephridia. posterioradductormuscleandposteriorfootretractors. 20. Lateralviewof leftnephridium. Scale bars: 13. 1.5, 16, 18 = 2 cm: 14, 17. 19, 20 = 2 mm. Page 234 THE NAUTILUS, Vol. 122, No. 4 hard bottoms formed by flattened basaltic stones, and the same asynchronous or sequential brooding pattern currents are strong. The collecting sites were small (i.e., brooding sacs contain more than one develop- ponds along the river course, where currents were low- ing generations of embiyos). Nevertheless, Coolev and er, allowingthe accumulation ofdecayed leaves and very O Foighil (2000) recognized Musculium as a monophy- soft, dark, and fine sand deposits, not deeper than 1 m, letic group. We allocate die new species in Sphaerium where specimens settle. Together with the Sphacrium until more e\idence is available tf) help v\ddi diis ques- samples, many specimens oi one species oiPisicliuiii sp. tion. More recently, a phylogenetic analysis of the (MCN 33918), and one of Diploclon sp. (MCN 33920) Sphaeriinae (Lee andO Foighil, 2003) basedonamolec- not yet identified, were found. ular study of nuclear (ITS-1) and mitochondrial (IBS) gene sequences of 15 species from North and South DISCUSSION America, Europe, Asia, and Australia, reco\ered a strongly suppoited monophvletic group of sequential Sphacriinn cambaraense is similar to Spliaciiiun forbesi brooders [Musculium and Sphaerium). However, die (Philippi, 1869) (from Bolivia, Cliile, and Peru). However, analyses indicate that Musculium and Sphaerium sensu S. cambaraense has a more decidedly triangular shell latoarenotnaturalgroups,proposinganewclassification outline, beaks not full with not marked nepiomc shell; system comprising five subgenera within Sphaerium: in addition. S. cambaraense is larger than S. forbesi. Sphaerium sensu stricto Scopoh, 1777; Musculium Sphaeriinn Iniiricocliac Philippi, 1869), alsoreportedfrom Link, 1807; Amesoda Rafinesque, 1820; Sphaerinova Bolivia, Chile, and Peru, diiiers from S. cambaraense Iredale, 1943, and Herringtonium Clarke, 1973. As these by its more rounded shell outline. In relation to shell subgeneric groupings, however well supported by thickness and microsti-uctm'e, S. cambaraense is similarto molecular data, are not defined from the moiphological the European species Sphaerium rivicola (Lamarck, point of view, it is not possible at this point to place 1818) and Sphaerium cornenm (Linnaeus, 1758); S. cambaraense within the newscheme. Dvduch-Falniowska (1983) reported for these species (as well as for Miiseiiliitm lacusfre (Miiller, 1774) and several ACKNOW'LEDCMENTS Pisidium species) sixdifferent layers, (1) periostracum, (2) homogeneous-granularlayer, (3) granularlayer; (4) diago- We are grateful to the curators of VICN mollusk nal layer (composite prismatic sti^ucture), (5) palisade collection: Ingrid Heydrich and Silvia D. Hahn for structiu'e, and (6) endo.stracuni. Onlv S. cornenm and pro\iding the loan of specimens; to Prof Dr. Cecilia S. livicola showed a different strvicture tcji' the diagonal Volkmer Ribeiro for the help in sampling and to layer, referredtoas"crossetl-lamellarstructure" (Dyduch- Prof Dr Wolfgang Maier from Tiibingen Lhii\ersit\'; Falniowska, 1983). This structiu'e was also found in Geniiany, for SEM sessions; F;abian Tricarico from the S. cambaraense. howexer. the diagonal pattern of the MACN SEM unit forhis fineworkwith SEM photography. plates has a different arrangement: in S. rivicola die oblique plates show a horizontal herringbone pattern and C.I. is a researcher from die Consejo Nacional de Investi- gaciones CientfficasvTecracas (CONICET),Ai'gentina. in S. cambaraense some rows of plates are oblique not formingahorizont;ilpattei'n. Theselatterresembleinpart the pseudocrossed-lamellarstructiu-e found in the Corbi- LITERATURE CITED culidae. Theperiostracum la\er in ,S'. cambaraense is thin- ner dian in S. conienm and the homogenecjus granular Cooley, L. R. and D. O Foigliil. 2(l()(). PlL\logenetic analysis layer is lacking. The simplified condition of posterior and of tlie Spliaeriidae (Mollusca: Bivalvia) based on partial right side of stomach is quite similar to tliat (oimd in mitochondrial 16S rDNA gene sequences. Invertebrate the Euperinae (Dreher-Mansurand Meier-Brook. 2000). Biolog)- 119: 299-308. The nephridium is relatixelv similar compared to D\xluch-FaInio\vska, A. 198.3. Shell Microstructure and Svs- tematics of .Sphaeriidae (Bi\al\ia, Eiilamellibrancliiata). S. cornenm (Dreher-Mansur and Meier-Brook, 2000), ActaZoologica Cracoviensia 16: 2.51-296. but the excretoiy sac and proximal loop are sliorter and Haas, F. 1949. Landand Siisswasseniiollusken aus deni Aniazo- the valve at the insertion ofthe distal loop into excretoiy nas Gebiete. Archivfur Molluskenkunde78(4/6): 149-156. sac is lacking in S. ccmibaraensis; the multilobed surface Haas, F. 1955. On some small collections ofinland shells from oflateral lobeisobservedforthe firsttime in Sphaerium. South America. Fieldiana, Zoolog)'34(35): 361-387. Based on the similar morpliologyofthe nephridium, Ituarte, C. 1995. Nuevos registros de Pi.-iidiuin Pfeiffer, 1821 y Korniushin (1998) proposed that South American spe- Sphaerium Scopoli, 1777 (Bivalvia: Sphaeriidiie) en Cliile, cies traditionally assigned to Sphaerium actually be- Bolivia y Noroeste argentint). Neotnipica 41(105-106): long to Musculium. According to Park and O Foighil 31-41. (2000), the usefulness ofthe fine anatomy ofnephridi- Ituarte, C. F. 1996. Argentine species of Pisidium Pfeiffer, um in the family Sphaeriidae is relative, due to its high T18h2e1,VealnigderMt3i.9'i1c8ul9i-u2in03L.ink, 1807 (BivaKia: Sphaeriidae). bmaosrpehdoloongimciatlocplhaosntdirciitayl. CIo6oSlervDanNdAOgFeonieglisi(l'((|2u0e0n0c)e,s Korni(inlshSipnl,i.i.\c.ri1u9n9i.Sas.. (NMootlelsusro.ni,thBei\;;iuli\aiat)omfvroofmstohmeetsrpoepciiceasl observed thai die Spltaerinm/MitscuUum clade exhibit region witii revision ol tlicii l:i\(iiiiiniir slatns, X'cstiiik moderate to low Icvc^ls of genetic divergences and zoologii 32(3): 3-12. M. C. D. Mansiiret 111.. 2()()S Patie 235 Koniiusliin, .-V. 199Sb. A comparative ime.stigation on nephri- of Sphaeriidae and Corbiculidae (Bivalvia: Veneroida). dia in (ingemail and pill clani.s. Malacological Re\iew, Archix'fiir Molluskenkunde 128(1/2): 1-59. Supplement 7: 53-63. Mansur, M. C. D., C. Schulz, M. G. O. Silva, and N. M. R. Kuiper, G. 1962. Notes sm' le ,s\stematiqne de.s pi.sidi's. Campos-Velho. 1991. Moluscos bivalves limnicos da Esta- J. J. Jovn-nal de Conch\liologie 102; .53-.57. yao Ecologica doTaini e areas adjacentes, Rio Grande do Kuiper. G. and \\'. Hinz. 19S4. Zur F"auna der Kkin- Sul. Brasil. Iheringia, Serie Zoologia, 71: 4.3-58. nmscJ.helnJ.in den Anden (BivaKia: Sphaeriidae). Archi\ Park, K. and D, 6 Foighil. 2000. Sphaeriid and corbiculid J. fiir Molluskenkmide 114(4/6): 137-1.56. clams represent separate heterodont bivaKe radiations Lee, T. and D. O Foighil. 2003. Phvlogenetic structure ofthe into freshwater enxironments. Molecular Ph)-logenetics Sphaeriinae, aglobalcladeoffreshwaterbi\aKe molluscs, and Evolution 14: 75-88. inferred from nuclear (ITS-1) and mitochondrial (16S) Pnrchon, R. D. 1958. The stomach in tlic Eiilainelliliranchia; ribosomal gene .sequences. Zoological Journal ot the Liii- Stomach tv-pe I\'. Proceedings ofthe Zoological Societ\'of nean Socieh' 137: 24.5-260. London 1.31: 487-525. Mmisur, M. C. D. and C. Meier-Brook. 2000. Moiphologn of Pnrchon, R, D 1960. Tlic stomach in the Eulamellibranchia; Eupera Bourguignat 1S54. and B\ssanodonta Orbign\' stomach t\pes \\ and \'. Proceedings of the Zoological 1S46 with contributions to the Ph\logenetic S\stematics Societ\' ol London ]o5: 431-489.