boletim do museu nacional - acd
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boletim do museu nacional - acd
BOLETIM DO MUSEU NACIONAL NOVA SÉRIE RIO DE JANEIRO - BRASIL ISSN 0080-312X ZOOLOGIA o N 516 29 DE ABRIL DE 2004 DESCRIPTION OF A NEW SPECIES OF WHIPTAILED STINGRAY FROM THE SOUTHWESTERN ATLANTIC OCEAN (CHONDRICHTHYES, MYLIOBATIFORMES, DASYATIDAE) 1 (With 11 figures) HUGO RICARDO SECIOSO SANTOS MARCELO R. DE CARVALHO 2 3 ABSTRACT: A new species of whiptailed stingray, Dasyatis hipostigma sp.nov., is described from the southwestern Atlantic Ocean and compared with Dasyatis species mostly from the Western and Eastern Atlantic. The new species differs from all congeners in presenting a sinuous, wshaped furrow ventrally at middisc over the coracoid bar just posterior to the gill openings (coracoid groove), dorsal surface of disc almost entirely naked, without enlarged denticles, spines or tubercles, outer corners of disc subangular, a weakly protruding snout, dorsal and ventral tailfolds about equal in height or dorsal tailfold slightly taller, and ventral tailfold much longer than dorsal tailfold. The new species has been misidentified by most previous authors as D. say, a species now restricted to the northwestern Atlantic Ocean, Gulf of Mexico, and Caribbean Sea. Dasyatis hipostigma sp.nov. is distributed from the states of Espírito Santo to Rio Grande do Sul, Brazil according to examined specimens, but probably occurs farther south to Mar del Plata, Argentina, in predominantly shallow coastal waters down to 80m in depth. Key words: Dasyatis hipostigma sp.nov., Dasyatidae; southwestern Atlantic Ocean; taxonomy. RESUMO: Descrição de uma espécie nova de raia-manteiga do sudoeste do Oceano Atlântico (Chondrichthyes, Myliobatiformes, Dasyatidae). Uma espécie nova de raia-manteiga, Dasyatis hipostigma sp.nov., é descrita do sudoeste do Oceano Atlântico e comparada com as demais espécies do gênero, particularmente com aquelas que ocorrem no Atlântico Leste e Oeste. A espécie nova difere das demais espécies de Dasyatis por apresentar um sulco sinuoso e raso na parte ventral do disco sobre o coracóide, ausência de dentículos dérmicos, espinhos ou tubérculos na superfície dorsal do disco e da cauda, extremidades laterais do disco não arredondadas, ponta do focinho não se projetando muito além da margem anterior do disco, e abas caudais dorsal e ventral mais ou menos da mesma altura, sendo que a aba ventral é bem mais longa que a dorsal. A nova espécie foi erroneamente identificada por muitos autores como D. say, uma espécie restrita ao noroeste do Atlântico, Golfo do México e Mar do Caribe. Dasyatis hipostigma sp.nov. está distribuída do Espírito Santo ao Rio Grande do Sul de acordo com o material examinado, mas provavelmente ocorre até Mar del Plata, Argentina, em águas costeiras rasas de até 80m de profundidade. Palavras-chave: Dasyatis hipostigma sp.nov., Dasyatidae, sudoeste do Oceano Atlântico, taxonomia. 1 Submitted on April 7, 2004. Accepted on April 26, 2004. 2 Museu Nacional/UFRJ, Programa de Pós-Graduação em Ciências Biológicas/Zoologia. Quinta da Boa Vista, São Cristóvão, 20940-040, Rio de Janeiro, RJ, Brasil. Universidade do Estado do Rio de Janeiro, Instituto de Biologia, Departamento de Zoologia. Rua São Francisco Xavier, 542, 20559-900, Rio de Janeiro, RJ, Brasil. E-mail: [email protected]. 3 Universidade de São Paulo, Departamento de Biologia (FFCLRP), Laboratório de Ictiologia de Ribeirão Preto (LIRP). Avenida dos Bandeirantes, 3900, 14040-901, Ribeirão Preto, SP, Brasil. E-mail:[email protected]. 2 H.R.S.SANTOS & M.R.CARVALHO INTRODUCTION Myliobatiformes (stingrays) are the second largest group of batoids, presently represented by some 185 species in 24 living genera (COMPAGNO, 1999). Recent authors have recognized from seven (CARVALHO, MAISEY & GRANDE, in press) to nine extant families (COMPAGNO, 1999) in the order, which has sometimes been treated as a suborder of Rajiformes (e.g., McEACHRAN & CARVALHO, 2002). Dasyatis Rafinesque, 1810 is the largest myliobatiform genus represented by at least 38 valid species, forming a varied assemblage that occurs worldwide in mostly shallow tropical and warm temperate waters (NISHIDA & NAKAYA, 1990; COMPAGNO, 1999; LAST & COMPAGNO, 2000; McEACHRAN & CARVALHO, 2002). Generic monophyly has yet to be convincingly demonstrated for Dasyatis, however, and few preliminary studies addressing its species-level relationships have been published (e.g., ROSENBERGER, 2001). Species of Dasyatis have been discovered in recent years (NISHIDA & NAKAYA, 1988a, 1988b; GOMES, ROSA & GADIG, 2000), even in fresh waters (ROBERTS & KARNASUTA, 1987), and some of them still await description (NISHIDA & NAKAYA, 1990; LAST & STEVENS, 1994). Six species of Dasyatis have been reported from the southwestern Atlantic Ocean off the coast of Brazil: the southern stingray, D. americana Hildebrand & Schroeder, 1928; the roughtail stingray, D. centroura (Mitchill, 1815); the wingfin stingray, D. geijskesi Boeseman, 1948; the longnose stingray D. guttata (Bloch & Schneider, 1801); the Brazilian large-eyed stingray, D. marianae Gomes, Rosa & Gadig, 2000; and the bluntnose stingray, D. say (Lesueur, 1817). Other dasyatids known from Brazil are the pelagic stingray Pteroplatytrygon violacea (Bonaparte, 1832), and the chupare stingray Himantura schmardae (Werner, 1904) (FIGUEIREDO, 1977; CHARVET-ALMEIDA et al., 2000; GOMES, ROSA & GADIG, 2000; GOMES & GADIG, 2003). We corroborate that D. sabina (Lesueur, 1824) does not occur in the southwestern Atlantic off Brazil (FIGUEIREDO, 1977). According to HILDEBRAND & SCHROEDER (1928), the Atlantic stingray D. sabina is distributed from Chesapeake Bay, Virginia (USA) to Brazil (see also GARMAN, 1913). BIGELOW & SCHROEDER (1953), however, following BOESEMAN (1948), doubted the Brazilian record for this species (originally credited to MÜLLER & HENLE, 1841), with which we fully agree because it has never been encountered here in collections or in the field. In this paper, we describe a new species of Dasyatis from Brazil that has been previously misidentified by most authors as D. say. Our report is based on extensive examinations of Western Atlantic species of Dasyatis, coupled with observations on Eastern Atlantic and Indo-Pacific forms, and is part of a larger study encompassing the comparative morphology and systematics of the Brazilian species of Dasyatis. MATERIAL AND METHODS Morphometric parameters, including snout angle, follow BIGELOW & SCHROEDER (1953) and COMPAGNO & ROBERTS (1982, 1984). Counts of oral papillae follow NISHIDA & NAKAYA (1990); other counts are according to COMPAGNO & ROBERTS (1984). Terminology for clasper elements follows TANIUCHI & ISHIHARA (1990). DW refers to disc width and TL to total length throughout. Institutional abbreviations follow LEVITON et al. (1985), with the following additions or corrections: AC.UERJ, Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 NEW SPECIES OF DASYATIS FROM THE SOUTHWESTERN ATLANTIC OCEAN 3 Anatomical Collection, Universidade do Estado do Rio de Janeiro (Departamento de Zoologia), Rio de Janeiro, Brazil; LIRP, Laboratório de Ictiologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil; MCP, Museu de Ciências e Tecnologia, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; NUPEC, Núcleo de Pesquisa e Estudos em Chondrichthyes, Santos, São Paulo, Brazil; UEFS, Universidade Estadual de Feira de Santana, Feira de Santana, Bahia, Brazil; UFPB, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil. A list of compartive material of Western Atlantic Dasyatis species examined is provided following the discussion. Dasyatis hypostigma sp.nov. (Figs.1-11) Holotype – BRAZIL - PARANÁ: Paranaguá, MCP 35005, adult , 760mm TL, 455mm DW, 70-80m, trawl net, C.M.Cunha col., XI/2002 (Figs.1-2). 1 Dasyatis hypostigma sp.nov., holotype , MCP 35005, 480mm DW: fig.1- dorsal view. Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 4 H.R.S.SANTOS & M.R.CARVALHO 2 Dasyatis hypostigma sp.nov., holotype , MCP 35005, 480mm DW: fig.2- ventral view. Paratypes (ten specimens) – BRAZIL - RIO DE JANEIRO: Búzios, UERJ 2008, , 590mm TL, 301mm DW, UERJ staff, 20/III/2002; Macaé, LIRP 5076, , 575mm TL, 185mm DW, UERJ staff, 27/IV/1993; Baía de Guanabara, UERJ 1898, , 285mm TL, 123mm DW, P.J.A.Rego col., 25/III/2001 (Fig.5); Pedra de Guaratiba, UERJ 2007, , 390mm TL, 170mm DW, UERJ staff, 8/III/2003; Baía da Ilha Grande, MZUSP 9915, , 620mm TL, 281mm DW, V/1966. SÃO PAULO: Cananéia, Ilha do Bom Abrigo, NUPEC 1831, , 670mm TL, 370mm DW; NUPEC 1832, , 725mm TL, 357mm DW; NUPEC 1833, , 650mm TL, 340mm DW, C.M.Cunha col., VII/2002, 65-75m, shrimp net. SANTA CATARINA: Porto Belo, MCP 4606, , 481mm TL, 250mm DW, MCP staff, XI/1969. RIO GRANDE DO SUL: UFRGS 1549, , 310mm TL, 155mm DW, UFRGS staff, Praia do Cassino, 25/XII/1982. Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 NEW SPECIES OF DASYATIS FROM THE SOUTHWESTERN ATLANTIC OCEAN 5 Additional material (51 specimens) – BRAZIL - RIO DE JANEIRO: Macaé, MNRJ uncatalogued (field number #0004650), , 1045mm TL, 580mm DW; Macaé, MNRJ uncatalogued (field number #00004682), , 630mm TL, 315mm DW; Macaé, MNRJ uncatalogued (field number #00004620), , 440mm TL, 240mm DW; Macaé, MNRJ uncatalogued (field number #00004655), , 480mm TL, 335mm DW (Fig.3); Macaé, MNRJ uncatalogued (field number #00004691), , 402mm TL, 247mm DW (Fig.4); Macaé, MNRJ uncatalogued (field number #00004800), , 380mm DW; Macaé, MNRJ uncatalogued (field number #00004626), , 680mm TL, 325mm DW; Cabo Frio, Praia do Forte, MNRJ 17717 (3), , 806mm TL, 502mm DW, , 701mm TL, 308mm DW, , 603mm TL, 302mm DW; Búzios, MNRJ uncatalogued (field number #00004654), , 730mm TL, 385mm DW; Búzios, MNRJ uncatalogued (field number #00004705), , 690mm TL, 360mm DW; Búzios, MNRJ uncatalogued (field number #00004701), , 420mm TL, 315mm DW; Búzios, MNRJ uncatalogued (field number #00004752), , 610mm TL, 310mm DW; Macaé, UERJ 1181, , 604mm TL, 281mm DW; Macaé, UERJ 1183, , 383mm TL, 172mm DW; Búzios, UERJ 2011, , 440mm TL, 220mm DW; Cabo Frio, UERJ 2009, , 425mm TL, 325mm DW; Cabo Frio, UERJ 2010, , 330mm DW; Rio de Janeiro, UERJ 789, , 345mm TL, 162mm DW; Praia de Jaconé, UERJ 690, , 321mm TL, 256mm DW; Angra dos Reis, Ilha Grande, UERJ 1667, , 349mm TL, 165mm DW; Mangaratiba, Muriqui, UERJ 2012, , 440mm TL, 200mm DW; Cabo Frio, AC.UERJ 1229-1, , 450mm TL, 280mm DW; Cabo Frio, AC.UERJ 1229-2, , 460mm TL, 285mm DW; Cabo Frio, AC.UERJ 1229-3, , 690mm TL, 305mm DW; Cabo Frio, AC.UERJ 1229-4, , 510mm TL, 225mm DW; Cabo Frio, AC.UERJ 1229-5, , 680mm TL, 315mm DW; Arraial do Cabo, AC.UERJ 531, , 640mm TL; 340mm DW; Urca, AC.UERJ 1228, , 280mm TL, , 115mm DW; Barra de Guaratiba, AC.UERJ 1224, , 410mm DW; Barra de Guaratiba, AC.UERJ 706, , 380mm DW; Barra de Guaratiba, AC.UERJ 705, , 340mm DW; Sepetiba, AC.UERJ 827, , 390mm DW; Ilha da Madeira, AC.UERJ 821, , 160mm DW; Angra dos Reis, AC.UERJ 1229, , 320mm DW; Atafona, MZUSP 9733, , 1080mm TL, 322mm DW, VII/1963. SÃO PAULO: Ubatuba, MZUSP 9709, , 770mm TL, 232mm DW, R.P.Lambalot col., VII/1969. SANTA CATARINA: Cabo de Santa Marta Grande, MZUSP 10595 (3), , 515mm TL, 267mm DW, , 709mm TL, 369mm DW, , 632mm TL, 345mm DW, VIII/1970, RV “Prof. W. Besnard”; 29º52’S, 49º37’W, MZUSP 10601(2), , 588mm TL, 320mm DW, , 582mm TL, 361mm DW (tail damaged), 08/IV/1972, RV “Prof. W. Besnard” (sta.1714); Porto Belo, MCP 4606, , 476mm TL, 252mm DW; MCP 2292, , 252mm TL, 105mm DW; MCP 2293, , 247mm TL, 101mm DW. RIO GRANDE DO SUL: 31º13’S, 50º35’W, MZUSP 10603 (1 of 2), , 741mm TL, 376mm DW, 11/IV/1972, RV “Prof. W. Besnard” (sta.1726); Praia do Hermenegildo, UFRGS 3165, , 289mm TL, 135mm DW; UFRGS 1586, , 77mm DW; UFRGS 1558, , 200mm DW; UFRGS 1584, , 254mm TL, 75mm DW. Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 6 H.R.S.SANTOS & M.R.CARVALHO 3 4 Dasyatis hypostigma sp.nov., dorsal view: fig.3- subadult , MNRJ “field number #00004655”, 335mm DW; fig.4- adult , MNRJ “field number #00004691”, 247mm DW (note that anterior disc and snout margins are slightly curled backward due to preservation). Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 NEW SPECIES OF DASYATIS FROM THE SOUTHWESTERN ATLANTIC OCEAN 7 5 Dasyatis hypostigma sp.nov., paratype, juvenile , UERJ 1898, 123mm DW: fig.5- dorsal view. Diagnosis – A medium-sized species of Dasyatis (reaching 580mm in DW), distinguished from all congeners, except the Japanese D. matsubarai Miyosi, 1939, by the presence of a conspicuous w-shaped sinuous groove or furrow ventrally at about middisc, just posterior to the last branchial openings (present in embryos, juveniles and adults). Dasyatis hypostigma sp.nov. is distinguished from D. matsubarai in having the dorsal surface of disc entirely naked even in adults, without a distinct dorsal median series of enlarged denticles at middisc, anteriorly over snout, and over tail midline (three to five dorsal middisc spines, enlarged denticles on snout, and midrow of tail spines present in adults of D. matsubarai). Other characters that in combination further distinguish the new species from Western Atlantic congeners are the following: outer corners of disc subangular, not broadly rounded; snout angular, not weakly convex; snout extremity not projecting significantly beyond anterior disc margin; dorsal and ventral tailfolds approximately equal in height, or dorsal tailfold slightly greater; ventral tailfold much longer than dorsal tailfold; dorsal disc surface without enlarged denticles, spines or tubercles. Description – Proportional dimensions as percentages of DW and tooth row counts are given separately in tables 1-2, respectively. Maximum size known ca. 455mm DW for males (holotype) and 580mm DW for females. Disc rhomboidal or diamond-shaped; disc length approximately equal to disc width (disc length 81-97% of DW). Snout angular and only slightly projecting as a distinct protuberance (Fig.6), with more or less straight anterolateral margins; Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 8 H.R.S.SANTOS & M.R.CARVALHO preorbital snout length 12-21% of DW (adults represent the greater value); preoral snout length length 17-22% of DW; prenasal snout length 13-18% of DW. Outer corners of disc narrowly rounded or subangular; posterolateral disc margins faintly convex; posterior extremities of pectoral fins broadly subangular. Snout angle 117-121° (n=29). Pupils relatively large, their length 33-48% of interorbital length, and 3-4% of DW. Eyes protrude well above level of disc. Spiracles rhomboidal and very large. 6 Dasyatis hypostigma sp.nov., holotype , MCP 35005, 480mm DW: fig.6- detail of anterior dorsal snout region. Nostrils elongate, slitlike, positioned slightly obliquely to midline. Posterolateral corners of nasal curtain broadly rounded; internasal curtain with fringed, faintly trilobate posterior margin (Fig.7). Mouth small, arched, midline of lower jaw with a prominent indentation; upper jaw with a distinct central lobe; mouth width ranging from 7-12% of DW and more or less equal to internarial width (mouth width 83-113% of internarial width). Palate with a strongly rugose texture and distinct central keel posterior to digitiform maxillary valve. Mouth floor with six oral papillae in embryos, and three, five or seven oral papillae in larger specimens; specimens with oral papillae always with three central papillae in transverse series on mouth floor (0-3-0), frequently with one or two extra pairs on each side of central series (either 1-3-1 or 2-3-2). Teeth arranged in quincunx pavement; teeth of juveniles and adult females with rounded, rhomboidal crowns; sexually mature males with heterodonty in lower jaws: teeth in first 10-12 lateral rows on each side of central tooth series rounded as in juveniles and females, but Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 NEW SPECIES OF DASYATIS FROM THE SOUTHWESTERN ATLANTIC OCEAN 9 central rows with elongate, sharp, posteriorly projecting cusps; upper jaw of mature males with many rows, even laterally, of sharp, elongate cusps (dignathic heterodonty). Dental formula for juveniles (above 300mm DW) and adults: 3746/43-50 (n=33; table 2). Gill apertures sinuous. Distance between first pair of gill slits 10-22% of DW; distance between first and fifth gill slits 12-15% of DW. Sinuous, w-shaped groove or furrow present ventrally at level of coracoid bar posterior to fifth branchial slits; coracoid groove present in all specimens, from embryos to adults of both sexes (Fig.8). 7 8 Dasyatis hypostigma sp.nov., morphological details: fig.7- nasoral region of holotype , MCP 35005, 480mm DW; fig.8- midventral region showing its diagnostic w-shaped coracoid furrow, paratype, juvenile , UERJ 2008, 301mm DW. Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 10 H.R.S.SANTOS & M.R.CARVALHO Table 1. Measurements of D. hypostigma sp.nov. (in mm and as % of disc width, DW). HOLOTYPE MORPHOMETRIC PARAMETERS mm RANGE % DW % DW MEAN SD total length 760 167 130-229 150 – disc width 455 100 100 100 0 disc length 406 89 81-98 88 4,9 internal disc length 363 79 73-97 80 6,9 precloacal length 333 73 67-88 75 5,7 tail length 378 83 56-154 77 – height of dorsal tailfold 2 length of dorsal tailfold 90 0,4 19 0,4 0,1-0,9 10-21 height of ventral tailfold 2 length of ventral tailfold 185 40 horizontal eye diameter 16 3 3-4 interorbital width 44 9 8-11 spiracle length 27 5 5-8 interspiracular length 69 15 preoral length 85 18 preorbital length 82 18 distance betw. 1st and 5st gill slits slitsslit 58 distance betw. 1st gill slits 0,3-0,9 21-41 0,3 10 0,3 22 0,3 8,8 0,3 – 3 0,5 10 0,8 6 0,8 19-8 15 2,4 16-22 18 1,4 12-20 12 9,1 12 12-15 13 1,0 83 18 10-22 18 2,6 mouth width 40 8 7-12 8 1,0 internasal width 40 8 8-10 8 0,8 pelvic fin length 49 17 10-18 14 4,8 clasper inner length 185 40 7-40 10 14,1 clasper outer length 70 15 3-22 5 8,3 155 115 100-137 85 54,0 65 14 13-18 15 1,3 snout-sting length prenasal length (SD) standard deviation. Number of specimens=32. Note that SD is not given for tail length as many specimens had lost the tail extremity (due to predation or mutilation when captured). The elevated SD for preorbital snout length and snout-sting length is due to the fact that neonates, juveniles and adults are lumped together for simplicity, and snout length proportions vary significantly among size-classes (also true for measurements pertaining to the clasper). Holotype is MCP 35005. Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 NEW SPECIES OF DASYATIS FROM THE SOUTHWESTERN ATLANTIC OCEAN Table 2. Tooth-row counts of Dasyatis hypostigma sp.nov. SIZE AND SEX TOOTH FORMULA NEONATES AND JUVENILES 77mm DW, (fetus) 27/28 155mm DW, 36/39 170mm DW 37/43 200mm DW, 37/43 206mm DW, 38/43 220mm DW, 37/43 225mm DW, 38/43 240mm DW, 38/42 250mm DW, 37/50 280mm DW, 40/46 281mm DW, 39/41 285mm DW, 38/48 301mm DW, 41/45 305mm DW, 40/45 310mm DW, 38/48 315mm DW, 39/43 315mm DW, 37/43 315mm DW, 41/46 320mm DW, 41/46 325mm DW, 42/46 325mm DW, 40/50 335mm DW, 41/44 340mm DW, 42/44 360mm DW, 37/43 390mm DW, 41/43 380mm DW, 42/46 385mm DW, 41/45 390mm DW 43/47 ADULTS 455mm DW, (holotype) 44/46 580mm DW, 46/48 Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 11 12 H.R.S.SANTOS & M.R.CARVALHO Pelvic fins protrude slightly from posterior disc margins (more apparent in freshly preserved specimens); pelvic fin length 10-18% of DW; pelvic fins with greater anterolateral margin, angular outer corners, and slightly convex posterior margins. Claspers very slender, elongate in holotype and adult males (males sexually mature as of ca. 400mm in DW), reaching caudally to just anterior to origin of caudal stings; clasper glans approximately one-half of clasper length in adult specimens; ventral pseudosiphon very elongate, about as long as clasper glans; small, subtriangular flap present at top of glans (Fig.9); dorsal pseudosiphon absent. Dorsal and ventral tailfolds present, just posterior to caudal stings, moderately developed, not flaplike (Figs.10,11H); dorsal tailfold usually about equal in height as ventral tailfold, but taller in some specimens; dorsal tailfold short in length, ranging from 29-42% of ventral tailfold length; dorsal tailfold more substantial, fleshy and rigid than ventral tailfold, and therefore better maintains original proportions in preserved material. Occasionally two caudal stings present, but most specimens with a single sting; pre-sting length (from tip of snout to sting origin) 100-137% of DW; sting(s) located just posterior to one-third of tail length. Total pre-sting vertebral centra (n=3, two males, one female) range from 99-106 in specimens 280-340mm DW; specimen with 99 total vertebrae with 39 mono- and 60 diplospondylic centra (320mm DW male); transition between mono- and diplospondylic vertebrae at about 38th centrum in 380mm DW female. A hundred and seventeen pectoral radials on right side and 115 on left in female, and 103 pectoral radials in 280mm DW male. Pelvic radials 24/19 (right/left) in 380mm DW female, 21 pelvic radials in both sides in 320mm DW male, and 19 radials in 280mm DW male. Dorsal surface of disc entirely smooth in all specimens, except for a single fully grown female (1045mm TL, 580mm DW, MNRJ uncatalogued, field number #0004650), which has very sparse, small but sharp spines with a somewhat random distribution on lateroposterior dorsal surface of disc and over anterior tail region (however, anterior and middle of dorsal disc entirely naked in this specimen, and spines over tail do not form a discrete midrow). Tailfolds, pelvic fins, claspers, and ventral surface of disc entirely smooth. Color in life brown, brownish-olive or yellowish-brown dorsally on disc, slightly darker over middisc, interorbital region and midtail, fading to a reddish-brown over posterolateral disc margins in freshly caught specimens. Ventral surface mostly white, but some specimens with sparse and very faint dark blotches at branchial region between and on gill slits, and with irregular greyish blotches at ventral middisc; ventral margins of disc and posterior margins of pelvic fins with a distinctly darker band. Caudal tailfolds black in living and freshly caught specimens. Color in preservative a light greyish-brown dorsally and white ventrally; tailfolds retain their black color in preserved specimens. Etymology – The specific name is a combination of the Greek hypo, meaning “ventral”, and stigma, meaning “mark”, in reference to the diagnostic coracoid furrow of this species. Geographical distribution – Dasyatis hypostigma sp.nov. has been recorded thus far from the southeastern and southern coasts of Brazil, ranging from the states of Espírito Santo to Rio Grande do Sul. Its northernmost limit may extend to the coast of Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 NEW SPECIES OF DASYATIS FROM THE SOUTHWESTERN ATLANTIC OCEAN 13 Bahia, but verifiable records are lacking. Literature accounts that mention Dasyatis species from northern and northeastern Brazil fail to register D. say, the name usually under which D. hypostigma sp.nov. has been recorded (QUEIROZ, SOUZA FILHO & SIMÕES, 1993; CASTRO, 1997; LESSA, 1997; LESSA et al., 1999; FEITOSA, PIMENTA & ARAÚJO, 2002). To the south, D. hypostigma sp.nov. ranges into Uruguay and Argentina as far as Mar del Plata, where it has been usually misidentified either as D. pastinaca or D. say (reviews in REFI, 1975; MENNI & STEHMANN, 2000). This species has been captured in mostly shallow water in depths of up to 80m (more common from 5-40m), and may also occur in estuarine regions. 9 10 Dasyatis hypostigma sp.nov., morphological details: fig.9- external morphology of left clasper in dorsal view, holotype , MCP 35005, 480mm DW: (ap) apopyle, (cg) clasper groove, (fl) flap, (gl) clasper glans, (pf) pelvic fin, (vps) ventral pseudosiphon; fig.10- dorsal and ventral tailfolds of specimen, juvenile , MNRJ “field number #00004626”, 325mm DW. Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 14 H.R.S.SANTOS & M.R.CARVALHO DISCUSSION The w-shaped coracoid groove (Fig.8) is absent from all other Western and Eastern Atlantic Dasyatis species, and has not been reported among stingrays with the exception of D. matsubarai (NISHIDA & NAKAYA, 1990). Dasyatis brevicaudata (Hutton, 1875) has a “transverse furrow present on belly behind gill slits” (LAST & COMPAGNO, 2000), which may be the coracoid groove but it is not described or figured (this species is compared to D. hypostigma sp.nov. below). The coracoid groove may represent the abdominal canal of the ventral lateral line complex (also J.D.McEACHRAN, Texas A & M University, pers.comm.), but it is not enclosed in a sensory canal nor does it contain pores or pitorgans (free neuromasts). The subpleural loop, formed by the infraorbital and hyomandibular canals, is adjacent to the coracoid groove in D. hypostigma sp.nov., but is clearly separated from it and runs the typical path described for other Dasyatis species (GARMAN, 1888; CHU & WEN, 1979; LOVEJOY, 1996). The abdominal canal has been found in “rhinobatoids” (except Rhina Bloch & Schneider, 1801 and Aptychotrema Norman, 1926), platyrhinids and Zanobatus Garman, 1913, and certain species of the rajid genus Dipturus Rafinesque, 1810 (McEACHRAN, DUNN & MIYAKE, 1996), in addition to the species of Dasyatis mentioned here; its loss was considered a stingray synapomorphy by McEACHRAN, DUNN & MIYAKE (1996). Whether the groove actually represents the abdominal canal will only be corroborated after more detailed study, but it is clearly a diagnostic character for D. hypostigma sp.nov. Western Atlantic Dasyatis comprise seven valid species, and some eight more Eastern Atlantic forms are known (COMPAGNO & ROBERTS, 1984; SÉRET, 1990; CAPAPÉ & DESOUTTER, 1990; COWLEY & COMPAGNO, 1993). We have compared D. hypostigma sp.nov. with specimens of most of these, as well as with specimens of various Indo-Pacific species, in addition to literature accounts treating the identification and distribution of Dasyatis worldwide (BIGELOW & SCHROEDER, 1953; STEHMANN, 1981; COMPAGNO & ROBERTS, 1984; MONKOLPRASIT, 1984; McEACHRAN & CAPAPÉ, 1989; NISHIDA & NAKAYA, 1990; SÉRET, 1990; COWLEY & COMPAGNO, 1993; LAST & STEVENS, 1994; COMPAGNO, 1995; McEACHRAN, 1995; GROVE & LAVENBERG, 1997; McEACHRAN & FECHHELM, 1999; LAST & COMPAGNO, 2000; McEACHRAN & CARVALHO, 2002; CARVALHO, SÉRET & McEACHRAN, in press). We have also compared D. hypostigma sp.nov. to a new species of Dasyatis from northern South America which has been submitted for publication elsewhere. Dasyatis hipostigma sp.nov. agrees with the Western Atlantic species D. say, D. americana, D. marianae, D. centroura, D. guttata, and D. sabina in having a diamondshaped or rhomboidal disc, but it is readily distinguished from them by the w-shaped coracoid groove. Of these, the new species more closely resembles D. americana and D. say in general proportions and overall appearance. Additional characters useful in differentiating D. hypostigma sp.nov. from Western and Eastern Atlantic Dasyatis are discussed below. Our observations indicate that D. guttata and D. hypostigma sp.nov. are the most common species of Dasyatis in the southwestern Atlantic. Dasyatis say, the species with which D. hypostigma sp.nov. has usually been misidentified in the literature (e.g. MIRANDA RIBEIRO, 1907, 1923; FIGUEIREDO, 1977), further differs from it in presenting a median dorsal and scapular rows of Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 NEW SPECIES OF DASYATIS FROM THE SOUTHWESTERN ATLANTIC OCEAN 15 enlarged spines (absent in D. hypostigma sp.nov.), a preorbital length about equal or just greater than interspiracular distance (preorbital length much greater than interspiracular length in D. hypostigma sp.nov.), shape of snout (anterior disc margins broadly convex and blunt in D. say, but more straight and pointed in D. hypostigma sp.nov.), and ventral tailfold conspicuously flaplike (Fig.11G), always broader than dorsal tailfold (ventral tailfold equal in height or more slender than dorsal tailfold in D. hypostigma sp.nov., and these never as well developed; Fig.11H). These differences are easily observed even in very small juveniles. Even though the largest specimen of D. hypostigma sp.nov. (an adult female 580mm in DW) bears scattered denticles over dorsal tail and posterior disc surfaces, this species cannot be confused with D. say due to the clearly distinct, posteriorly projecting, enlarged spines in a single row over middisc and scapular region in the latter species (both are present even in small juveniles of D. say ). It is feasible that D. hypostigma sp.nov. only develops spination at a very large size, at least over 510mm in DW, but this seems highly improbable because the development of spination occurs at a much earlier stage in stingrays (and batoids in general), and is usually already present in small juveniles; we interpret the faint spination of the largest specimen as abnormal for D. hypostigma sp.nov. because it is the only specimen with any dermal denticles encountered thus far (another large female of 502mm DW and a male of 455mm DW are completely devoid of denticles). The confusion between D. say and D. hypostigma sp.nov. is due, at least in part, to MIRANDA RIBEIRO (1907, 1923) and to the otherwise excellent account of BIGELOW & SCHROEDER (1953). The latter authors included numerous southwestern Atlantic specimens in their detailed descriptions of D. say, setting the stage for subsequent misidentifications. Their material of “D. say” from the southwestern Atlantic may have also included specimens of D. americana, according to their description of a large male from Rio de Janeiro (615mm DW) with numerous enlarged denticles on middisc and tail (BIGELOW & SCHROEDER, 1953). The enlarged denticles in this specimen continue over the tail base to close to the caudal stings, which agrees more with typical D. americana than with typical D. say. MIRANDA RIBEIRO’s (1907, 1923) descriptions of “D. say” are puzzling, as he credits this species as having a better developed ventral tailfold compared to the dorsal one, which is certainly not the case in D. hypostigma sp.nov. The dorsal tailfold always appears more prominent in this species, even in poorly preserved material, due to its fleshier texture (even though it is usually as tall as the ventral tailfold). His description, however, could have been partially compiled from accounts based on North Atlantic material. Dasyatis americana is promptly differentiated from D. hypostigma sp.nov. by presenting a median dorsal and scapular rows (one on each side) of larger spinelike denticles, in addition to smaller denticles in interorbital region and elsewhere (for details, see BIGELOW & SCHROEDER, 1953), as well as a dorsal tailfold always much smaller in height than ventral tailfold (Fig.11A), itself conspicuously well developed. Furthermore, males of D. americana become sexually mature at only about 500mm DW according to our material, whereas D. hypostigma sp.nov. males have fully calcified claspers by 400mm DW. Tailless specimens of both species, including small juveniles, can be distinguished on the basis of their dermal covering. In addition to presenting a median dorsal and scapular rows of enlarged denticles and both tailfolds well developed and terminating on same vertical on tail (Fig.11D), Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 16 H.R.S.SANTOS & M.R.CARVALHO the highly distinctive D. marianae is distinguished from D. hypostigma sp.nov. by having a reduced interorbital length due to its greater eye diameter (about equal to interorbital distance, vs. eye diameter 33-48% of interorbital distance in D. hypostigma sp.nov.). Dorsal and ventral coloration easily separates both species as well. Dasyatis marianae has dark interspiracular, scapular and precaudal marks dorsally, along with dark longitudinal bands on disc (these may fade in preservative). Ventrally, this species is unique in having symmetrical dark blotches at middisc, sometimes with a large central blotch (GOMES, ROSA & GADIG, 2000), all of which are absent from D. hypostigma sp.nov. The very unique D. centroura lacks a developed dorsal tailfold (a low dermal crest is sometimes present; Fig.11B), and is endowed with a dense covering of small denticles as well as enlarged tubercles and prominent spines on the dorsal surface of disc and tail; it also has proportionally smaller eyes than other Western Atlantic Dasyatis (e.g. BIGELOW & SCHROEDER, 1953). This species reaches over 2000mm in DW (McEACHRAN & FECHHELM, 1999; McEACHRAN & CARVALHO, 2002), whereas the maximum DW registered for D. hypostigma sp.nov. is 580mm, and sexually matures at a much greater size than D. hypostigma sp.nov., at about 1300-1600mm in DW (both males and females). The other Western Atlantic species of Dasyatis (D. sabina, D. guttata and D. geijskesi ) are relatively long-snouted forms, especially the latter (preorbital snout length over 35% of DW, vs. some 20% in adults of D. hypostigma sp.nov.). Dasyatis sabina and D. geijskesi also have broadly rounded disc corners (subangular in D. hypostigma sp.nov.). Dasyatis geijskesi is unique among Dasyatis species in possessing extremely wide and anteroposteriorly short pelvic fins with acute corners, sometimes visible in dorsal view projecting laterally beyond the disc; it shares with D. acutirostra Nishida & Nakaya, 1988 from the East China Sea strongly concave anterolateral disc margins and very small eyes [disc outline is slightly similar in the Indo-Pacific D. zugei (Müller & Henle, 1841), a species lacking oral papillae]. Dasyatis sabina, D. guttata, and D. geijskesi have a definite median row of enlarged dorsal spines along midline and numerous interorbital denticles, and both D. guttata and D. geijskesi have a broad median band of low, closely packed denticles on dorsal disc (more developed in D. guttata). Dasyatis guttata and D. geijskesi also have very low dorsal tailfolds or keels, and in D. sabina the ventral tailfold is distinctly more developed than the dorsal one (Fig.11C, F and E, respectively). The eight Eastern Atlantic species of Dasyatis (not counting D. centroura and D. americana, both recorded from West Africa; COMPAGNO & ROBERTS, 1984; cf. SÉRET, 1990) are readily distinguished from D. hypostigma sp.nov. Dasyatis ukpam (Smith, 1863) is a thick-bodied, fresh water species with a rudimentary caudal sting (when present), a somewhat oval disc with broadly rounded corners, and an intense covering of enlarged spinelike denticles over entire dorsal disc area. This species is sometimes placed in Urogymnus (COMPAGNO, 1999) due to its similarity with the marine Urogymnus africanus (Bloch & Schneider, 1801, =? Raja asperrimus Bloch & Schneider, 1801), which also has an intense shagreen of large conical spines. Dasyatis margarita (Günther, 1870), D. garouaensis Stauch & Blanc, 1962, and D. margaritella Compagno & Roberts, 1984 have numerous denticles over middorsal region, forming a more or less demarcated band on disc (especially D. margarita and D. margaritella). All three species present a pearl-spine Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 NEW SPECIES OF DASYATIS FROM THE SOUTHWESTERN ATLANTIC OCEAN 17 dorsally at disc center (sometimes absent in D. garouaensis, more developed in D. margarita; also present in D. ukpam), as well as a faintly oval (not rhomboidal) disc with broadly rounded corners and a protruding snout. Dasyatis garouaensis also has flattened midscapular spines, and is restricted to fresh waters of western Central Africa. Moreover, D. garouaensis, D. margarita, and D. margaritella have only a low dorsal keel on tail (entirely absent in D. ukpam), whereas D. hypostigma sp.nov. has a conspicuous dorsal tailfold (for a more detailed description of these species, see GÜNTHER, 1870; COMPAGNO & ROBERTS, 1984; SÉRET, 1990; CARVALHO, SÉRET & McEACHRAN, in press). The Eastern Atlantic D. chrysonota (Smith, 1828) and D. marmorata (Steindachner, 1892) may represent only clinal extremes (COWLEY & COMPAGNO,1993), but are nevertheless easily separated from D. hypostigma sp.nov. by their dorsal color pattern, composed of irregular reticulate blue markings and blotches on a light brown background, unique among Dasyatis species (see also KREFFT, 1968). In D. rudis (Günther, 1870), the dorsal disc and most of tail are covered with small denticles (larger ones also dorsally on tail), adults have over 100 tooth rows in each jaw, and the dorsal tailfold is reduced to a small keel (GÜNTHER, 1870; FOWLER, 1936; SÉRET, 1990). D. pastinaca (Linnaeus, 1758) (including D. tortonesei Capapé, 1977 as a junior synonym; SÉRET & McEACHRAN, 1986) is mostly devoid of a dermal covering as in D. hypostigma sp.nov., but a midrow of enlarged denticles with narrow bases occurs at disc midline, over scapular region, and over tail anterior to caudal stings, as well as small, closely-set denticles posterior to caudal stings; this species also has a proportionally longer dorsal tailfold and shorter ventral tailfold compared to D. hypostigma sp.nov. (TORTONESE, 1956; SÉRET, 1990; NOTARBARTOLO-DI-SCIARA & BIANCHI, 1998). The tail region is distinctly thorny in D. brevicaudata and especially in D. thetidis Ogilby, 1899, both very large Indo-Pacific species (ca. 2m in DW) present off South Africa but so far unrecorded in the Eastern Atlantic (both species are described in detail and illustrated in LAST & STEVENS, 1994). Dasyatis brevicaudata, as mentioned above, may also have the coracoid furrow, but in addition to its thorny tail, it is separated from D. hypostigma sp.nov. by presenting minute white spots laterally on disc, a rudimentary dorsal tailfold, and a short tail that is broad at base and tapers posteriorly as of level of stings (see also GARRICK, 1954; WALLACE, 1967). The widespread Indo-Pacific D. kuhlii (Müller & Henle, 1841), also known from eastern South Africa, has a reddish-brown dorsal background with blue ocelli and scattered black spots, in addition to vertical bands on tail (COMPAGNO & HEEMSTRA, 1984). Further characters that differentiate South African Dasyatis from D. hypostigma sp.nov. are described in WALLACE (1967), COMPAGNO, EBERT & SMALE (1989), COWLEY & COMPAGNO (1993), and COMPAGNO (1995). The dorsal tailfold of D. hypostigma sp.nov. superficially resembles that of D. leylandi Last, 1987 from Australia and New Guinea in being relatively short compared to the ventral tailfold, and in having steeply inclined anterior and posterior margins. Both species are easily distinguished by color and spination: D. leylandi has a reticulate dorsal aspect with a dark band across eyes and spiracles and vertical dark bars on tail, and is endowed with closely packed nuchal denticles. All Australian, southeast Asian, Western Pacific, and Indian Ocean Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 18 H.R.S.SANTOS & M.R.CARVALHO species of Dasyatis are variously covered with denticles and spines over tail, nuchal, scapular and middisc regions (with the exception of D. izuensis Nishida & Nakaya, 1988), either have low dorsal tailfolds resembling keels or dorsal tailfolds that are not as developed as ventral tailfolds, and present distinctive color patterns on disc, snout and tail posterior to stings (NISHIDA & NAKAYA, 1990; LAST & STEVENS, 1994; LAST & COMPAGNO, 2000). Fig.11- Tailfolds of Western Atlantic species of Dasyatis, in lateral view. (A) D. americana, (B) D. centroura, (C) D. guttata, (D) D. marianae, (E) D. sabina, (F) D. geisjkesi, (G) D. say, (H) D. hypostigma sp.nov. (see also figure 10). (A-C) and (E-G) modified from BIGELOW & SCHROEDER (1953), (D) and (H) original. Not to scale. Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 NEW SPECIES OF DASYATIS FROM THE SOUTHWESTERN ATLANTIC OCEAN 19 ADDITIONAL DASYATIS SPECIMENS EXAMINED (only Western Atlantic material is listed) Dasyatis americana (17 specimens) – USA - MARYLAND: Crisfield, USNM 88378 (holotype), , 931mm TL, 436mm DW. LOUSIANA: 28°39’N, 95°45’W, Gulf of Mexico, MCZ 40776, 213mm DW (photograph of midventral disc only); 29°24’N, 94°25’W, Gulf of Mexico, MCZ 40772, 220mm DW (photograph of midventral disc only). FLORIDA: Palmetto Key, AMNH 44086 (2), , 520mm TL, 179mm DW, 446mm TL, 160mm DW; AMNH uncatalogued, , 611mm TL, 235mm DW. BAHAMAS - NORTH BIMINI: East side of North Lagoon, AMNH 74722, , 895mm TL, 378mm DW. BRAZIL - RIO GRANDE DO NORTE: Atol das Rocas, MZUSP 9925, , 667mm TL, 411mm DW. ALAGOAS: Maceió, Lagoa Mundaí, MZUSP 28734, , 615mm TL, 178mm DW. RIO DE JANEIRO: Búzios, Praia de Manguinhos, MNRJ 11232, , 715mm TL, 358mm DW; Angra dos Reis, MZUSP 9916, , 856mm TL, 343mm DW; MZUSP 12757, , 690mm TL, 190mm DW; MZUSP uncatalogued, , 630mm TL, 194mm DW. SÃO PAULO: Canal de São Sebastião: LIRP 1554, , 650mm DW, F.Z.Gibran; LIRP 1555, , 595mm DW; LIRP 1556, , 540mm DW; LIRP 1557, , 500mm DW. Dasyatis centroura (15 specimens) – USA - NORTH CAROLINA: 35o23’N, 76o26’W, AMNH 49556 (4), , 801mm TL, 282mm DW, , 815mm TL, 360mm DW, 789mm TL, 298mm DW, 775mm TL, 283mm DW. SOUTH CAROLINA: 33o32’N, 77o59’W, AMNH 49555 (2), , 889mm TL, 308mm DW, 864mm TL, 350mm DW. FLORIDA: 29o36’-29o33’N, 81o06’-81o05’W, AMNH 76592, , 727mm TL, 233mm DW. BRAZIL - RIO DE JANEIRO: UERJ 785, , 574mm TL, 184mm DW. SÃO PAULO: Santos: NUPEC 1775, , 1300mm TL, 560mm DW; NUPEC 1776, , 950mm TL, 380mm DW; NUPEC 1777, , 1145mm TL, 460mm DW; NUPEC 1778 (2), , 1133mm TL, 560mm DW, 880mm TL, 360mm DW; NUPEC 1780, , 1180mm TL, 515mm DW; NUPEC 1781, , 133mm TL, 560mm DW. Dasyatis geijskesi (eight specimens) – SURINAM: NNM 20487 (holotype), , 340mm DW. BRAZIL - AMAPÁ: 02o32’N, 49o17’W, USNM uncatalogued, , 1109mm TL, 294mm DW. PARÁ: Baía de Marajó: MPEG 3400, , 580mm TL, 296mm DW; MPEG 3401, , 995mm TL, 204mm DW; MPEG 3402, , 1420mm TL, 326mm DW; MPEG 3404, , 950mm TL, 243mm DW; NUPEC 1814, , 2230mm TL, 570mm DW; UERJ 1980, , 2166mm TL, 550mm DW. Dasyatis guttata (31 specimens) – GUATEMALA - PUERTO BARRAS: Baía de Amatique, AMNH uncatalogued, , 828mm TL, 228mm DW. BRAZIL MARANHÃO: Pagé, Ilha São Luis, Estreito de Coqueiro, MZUSP 72816, , 1298mm TL, 500mm DW. PARÁ: Baía de Marajó: MPEG 2274, , 1227mm TL, 419mm DW; MPEG 2275, , 1719mm TL, 428mm DW; MPEG 2325, , 821mm TL, 269mm DW; MPEG 3406, , 1117mm TL, 270mm DW; MPEG 3407, , 596mm TL, 343mm DW. SERGIPE: Aracajú, MZUSP 72817, , 951mm TL, 250mm DW; Pirambú: UERJ 1086, , 1130mm TL, 328mm DW; UERJ 1087, , 1300mm TL, 391mm DW. BAHIA: Baía de Todos os Santos, MZUSP 72815, , 785mm TL, 246mm DW; Município de Maragogipe, Barra do Paraguaçu, MZUSP 72820 (4), , Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 20 H.R.S.SANTOS & M.R.CARVALHO 775mm TL, 233mm DW, 646mm TL, 190mm DW, 701mm TL, 195mm DW, , 722mm TL, 221mm DW; Caravelas, Praia do Couraço, UERJ 738, , 848mm TL, 285mm DW; Município de Prado, UERJ 1088 (2), , 845mm TL, 256mm DW, , 852mm TL, 229mm DW. RIO DE JANEIRO: Angra dos Reis, MZUSP 3669, , 553mm TL, 190mm DW; MNRJ 571, , 1174mm TL, 387mm DW, “BRAZIL”, no further data; MNRJ 600 (2), , 621mm TL, 226mm DW, 734mm TL, 230mm DW, no data; Mangaratiba, Muriqui: AC.UERJ 1220, , 1125mm TL, 415mm DW; AC.UERJ 1221, , 800mm DW (damaged tail); AC.UERJ 1222, , 1000mm TL, 350mm DW; AC.UERJ 1223, , 1170mm TL, 405mm DW. SÃO PAULO: Santos, MNRJ 602, , 862mm TL, 261mm DW; MNRJ 5712, , 699mm TL, 205mm DW, “BRAZIL”, no further data; MNRJ 15162, , 1199mm TL, 232mm DW, no data; MNRJ 15162, , 769mm TL, 295mm DW, no data; Canal de São Sebastião, LIRP 1558, , 291mm DW, F.Z.Gibran. Dasyatis marianae (nine specimens) – BRAZIL - CEARÁ: Fortaleza, Mucuripe, MNRJ 13454 (paratype), , 223mm TL, 110mm DW, IV/1945. RIO GRANDE DO NORTE: Natal, AMNH 3882 (paratype), , 520mm TL, 264mm DW, E.C.Starks col., 1911. PARAÍBA: Cabedelo, UFPB 663 (paratype), , 264mm TL, 143mm DW, G.Cannella col., 24/VII/1980; João Pessoa, Manaíra: UFPB 2661 (paratype), , 294mm TL, 151mm DW, R.S.Rosa and C.Murilo cols., 23/XI/1988; UERJ 1700 (paratype), , 484mm TL, 247mm DW. PERNAMBUCO: Recife, Município de Conde, Praia de Tabatinga, MNRJ 7967 (holotype), , 433mm TL, 235mm DW, H.Berla col., 13/X/1944; MNRJ 7418 (paratype), , 442mm TL, 236mm DW, same data as MNRJ 7967, but collected on 14/VIII/1944; Itamaracá, Praia de Jaguaribe, UEFS 472 (paratype), , 233mm TL, 125mm DW, B.G.A.Albuquerque and P.R.D.Lopes cols., 7/XII/1991. BAHIA: Município de Vera Cruz, Ilha de Itaparica, Praia de Aratuba, UEFS 106, , 246mm TL, 149mm DW, N.A.Coelho col., 11/XII/1988. Dasyatis sabina (five specimens) – USA - TEXAS: Port Aransas, Corpus Christi Bay, AMNH 96784 (3), , 252mm TL, 189mm DW, , 557mm TL, 230mm DW, 372mm TL, 170mm DW. ALABAMA: Gulf of Mexico, vicinity of Dauphin Island, AMNH 98229, , 628mm TL, 251mm DW. FLORIDA: Gulf of Mexico, Pine Island, CAS 35485, , 235mm TL, 87mm DW. Dasyatis say (five specimens) – USA - VIRGINIA: 37o18’N, 75o40’W, AMNH 75717, , 491mm TL, 121mm DW; VIMS uncatalogued, , 172mm TL, 73mm DW, no data; AMNH uncatalogued, , 900mm DW, no data. FLORIDA: Volusia, MCZ 36402, 275mm DW (photograph of midventral disc only); 28°14’N, 80°31’W, MCZ 49018, 210mm DW (photograph of midventral disc only). ACKNOWLEDGMENTS Numerous collection managers and curators provided material, work space or assistance in various ways related to this project, and are sincerely thanked for their hospitality: S.A.Schaefer, M.L.J.Stiassny, B.Brown, and R.Arrindell (AMNH); B.Séret, P.Pruvost, and G.Duhamel (MNHN); G.W.Nunan, D.F.Moraes Jr., L.R.G.Rodrigues, Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 NEW SPECIES OF DASYATIS FROM THE SOUTHWESTERN ATLANTIC OCEAN 21 and C.Amorim (MNRJ); M.Parrent (MRAC), J.L.Figueiredo and O.Oyakawa (MZUSP); A.C.Gill, D.J.Siebert, O.Crimmen, and P.Campbell (NHM); M.Oijen (NNH), L.R.Malabarba, C.Lucena, and Z.M.Lucena (MCP); M.M.Gonzalez and C.M.Cunha (NUPEC); J.D.McEachran (TCWC); P.Lopes (UEFS); U.L.Gomes, V.Gallo, P.J.A.Rego, and L.F.L.Fonseca (UERJ); L.R.Parenti, L.Palmer, L.Knapp, and J.Finan (USNM); and H.Wilkens and G.Schulze (ZMH). K.Hartel and C.Kenaley (MCZ) kindly provided information on North American D. say and D. americana. U.L.Gomes is thanked for discussions concerning the identification of Dasyatis species in general, and for generously sharing data. M.R.Carvalho is particularly grateful to J.D.McEachran for his input and incentive. F.A.Bockmann, R.Benine, and Murilo de Carvalho (LIRP) are thanked for assistance in various ways. Financial support to M.R.Carvalho was provided by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP Proc. 02/06459-0). LITERATURE CITED BIGELOW, H.B. & SCHROEDER, W.C., 1953. Fishes of the Western North Atlantic. Part 2: Sawfishes, guitarfishes, skates and rays. Memoir Sears Foundation for Marine Research, New Haven, 1(2):1-558. BOESEMAN, M., 1948. Some preliminary notes on Surinam sting rays, including the description of a new species. Zoologische Mededelingen, Leiden, 30(2):31-47. CAPAPÉ, C. & DESOUTTER, M., 1990. Dasyatidae. In: QUERO, J.C.; HUREAU, C.; KARRER C.; POST, A. & SALDANHA, L. (Eds.) Check-list of fishes of the eastern tropical Atlantic (CLOFETA). Paris: Unesco. v.1, p.59-63. CARVALHO, M.R.; MAISEY, J.G. & GRANDE, L., in press. Freshwater stingrays of the Green River Formation of Wyoming (Early Eocene), with the description of a new genus and species and an analysis of its phylogenetic relationships (Chondrichthyes: Myliobatiformes). Bulletin of the American Museum of Natural History, New York. CARVALHO, M.R.; SÉRET, B. & McEACHRAN, J.D., in press. Dasyatidae. In: TEUGELS, G.; STIASSNY, M.L.J. & HOPKINS, C. (Eds.) Fishes of the Freshwaters of the Lower Guinea Ichthyogeographical province: Cameroon, Equatorial Guinea, Gabon and CongoBrazzaville. Tervuren: MRAC, AMNH & IRD. CASTRO, A.C.L., 1997. Características ecológicas da ictiofauna da ilha de São Luis-MA. Boletim do Laboratório de Hidrobiologia, São Luis, 10:1-18. CHARVET-ALMEIDA, P.; BARTHEM, R.B.; RINCÓN, G. & ALMEIDA, M.P., 2000. Registro de ocorrência de Himantura schmardae (Chondrichthyes: Dasyatidae) na costa norte do Brasil. In: REUNIÃO DA SOCIEDADE BRASILEIRA PARA O ESTUDO DE ELASMOBRÂNQUIOS, 2., Santos. Resumos..., Santos, p.80. CHU, Y.T. & WEN, M.C., 1979. A study of the lateral-line canal systems and that of lorenzini ampullae and tubules of elasmobranchiate fishes of China. Monograph of Fishes of China 2. Shanghai: Shanghai Science and Technology Press. 132p., 64pls. COMPAGNO, L.J.V., 1995. Dasyatidae. In: SMITH, M.M. & HEEMSTRA, P.C. (Eds.) Smiths’ Sea Fishes. Johannesburg: Southern Book Publishers. p.135-142. COMPAGNO, L.J.V., 1999. Checklist of living elasmobranches. In: HAMLETT, W.C. (Ed.) Sharks, Skates, and Rays, The Biology of Elasmobranch Fishes. Baltimore: John Hopkins Univ. Press. p.471-498. COMPAGNO, L.J.V.; EBERT, D.A. & SMALE, M.J., 1989. Guide to the Sharks and Rays of Southern Africa. Cape Town: Struik. 160p. COMPAGNO, L.J.V. & HEEMSTRA, P.C., 1984. Himantura draco, a new species of stingray (Myliobatiformes: Dasyatidae) from South Africa,with a key to the Dasyatidae and the first record of Dasyatis kuhlii (Müller & Henle, 1841) from southern Africa. JLB Smith Institute of Ichthyology, Grahamstown, 33 (Special Publication):1-17. Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 22 H.R.S.SANTOS & M.R.CARVALHO COMPAGNO, L.J.V. & ROBERTS, T.R., 1982. Freshwater stingrays (Dasyatidae) of Southeast Asia and New Guinea, with description of a new species of Himantura and reports of unidentified species. Environmental Biology of Fishes, Dordrecht, 7(4):321-339. COMPAGNO, L.J.V. & ROBERTS, T.R., 1984. Marine and freshwater stingrays (Dasyatidae) of West Africa, with description of a new species. Proceedings of the California Academy of Sciences, San Francisco, 43(18):283-300. COWLEY, P.D. & COMPAGNO, L.J.V., 1993. A taxonomic re-evaluation of the blue stingray from southern Africa (Myliobatiformes: Dasyatidae). South African Journal of Marine Science, Cape Town, 13:135-149. FEITOSA, C.V.; PIMENTA, D.A.S & ARAÚJO, M.E., 2002. Ictiofauna recifal dos parrachos de Maracajú (RN) na área dos flutuantes: inventário e estrutura da comunidade. Arquivos de Ciências do Mar, Fortaleza, 35:39-50. FIGUEIREDO, J.L., 1977. Manual de peixes marinhos do sudeste e sul do Brasil. I. Introdução, tubarões, raias e quimeras. São Paulo: Museu de Zoologia da Universidade de São Paulo. 104p. FOWLER, H.W., 1936. The marine fishes of west Africa based on the collection of the American Museum Congo expedition, 1909–1915. Part 1. Bulletin of the American Museum of Natural History, New York, 70:1-605. GARMAN, S., 1888. On the lateral-line canal system of the Selachia and Holocephala. Bulletin of the Museum of Comparative Zoology of Harvard University, Cambridge, 17(2):57-119. GARMAN, S., 1913. The plagiostomia. Memoirs of the Museum of Comparative Zoology of Harvard University, Cambridge, 36:1-528. GARRICK, J.A.F., 1954. Studies on New Zealand Elasmobranchii. Part II. A description of Dasyatis brevicaudatus (Hutton), Batoidei, with a revision of records of the species outside New Zealand. Transactions of the Royal Society of New Zealand, Wellington, 82(1):189-198. GOMES, U.L. & GADIG, O.B.F., 2003. Dasyatidae. In: MENEZES, N.A.; BUCKUP, P.A.; FIGUEIREDO, J.L. & MOURA, R.L. (Eds.) Catálogo das espécies de peixes marinhos do Brasil. São Paulo: Museu de Zoologia da Universidade de São Paulo. p.30. GOMES, U.L.; ROSA, R.S & GADIG, O.B.F., 2000. Dasyatis marianae sp.n.: a new species of stingray (Chondrichthyes: Dasyatidae) from the Southwestern Atlantic. Copeia, Lawrence, 2000(2):510-515. GROVE, J.S. & LAVENBERG, R.J., 1997. The fishes of the Galápagos Islands. Stanford: Stanford University Press. 883p. GÜNTHER, A., 1870. Catalogue of the Fishes in the British Museum. London: British Museum (Natural History). v.8, 549p. HILDEBRAND, S.F. & SCHROEDER, W.C., 1928. Fishes of Chesapeake Bay. Bulletin of the Unites States Bureau of Fisheries. v.43, 388p. [reprinted 1972 by TFH Publications: Neptune]. KREFFT, G., 1968. Knorpelfische (Chondrichthyes) aus dem tropischen Ostatlantik. Atlantide Report, Copenhagen, 10:33-76. LAST, P.R. & COMPAGNO, L.J.V., 2000. Urolophidae. In: CARPENTER, K.E. & NIEM, V. (Eds.) FAO species identification guide for fisheries purposes. The living marine resources of the western Central Pacific Ocean. Rome: FAO. p.1468-1476. LAST, P.R. & STEVENS, J.D., 1994. Sharks and rays of Australia. Melbourne: CSIRO. 513p., 84pls. LESSA, R.P., 1997. Sinopse dos estudos sobre elasmobrânquios da costa do Maranhão. Boletim do Laboratório de Hidrobiologia, São Luis, 10:29-36. LESSA, R.P.; SANTANA, F.M.; RINCÓN, G. & GADIG, O., 1999. Diagnóstico da biodiversidade de elasmobrânquios no Brasil. Brasília: Ministério do Meio Ambiente. 167p. LEVITON, A.E.; GIBBS JR., R.H.; HEAL, E. & DAWSON, C.E., 1985. Standards in herpetology and ichthyology: Part I. Standard symbolic codes for institutional resource collections in herpetology and ichthyology. Copeia, Lawrence, 1985(3):803-832. Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 NEW SPECIES OF DASYATIS FROM THE SOUTHWESTERN ATLANTIC OCEAN 23 LOVEJOY, N.R., 1996. Systematics of myliobatoid elasmobranchs: with emphasis on the phylogeny and historical biogeography of neotropical freshwater stingrays (Potamotrygonidae: Rajiformes). Zoological Journal of the Linnaean Society, London, 117:207-257. McEACHRAN, J.D., 1995. Dasyatidae. In: FISCHER, W.; KRUPP, F.; SCHNEIDER, W.; SOMMER, C.; CARPENTER, K.E. & NIEM, V.E. (Eds.) Pacifico Centro Oriental. Rome: FAO. v.2, p.752-755. McEACHRAN, J.D. & CAPAPÉ, C., 1989. Dasyatidae. In: WHITEHEAD, P.J.P.; BAUCHOT, M.L.; HUREAU, J.C.; NIELSEN, J. & TORTONESE, E. (Eds.) Fishes of the North East Atlantic and Mediterranean. Paris: Unesco. v.1, p.197-202. [reprint edition with corrections of 1984 original] McEACHRAN, J.D. & CARVALHO, M.R., 2002. Dasyatidae. In: CARPENTER, K.E. (Ed.) The Living Marine Resources of the Western Central Atlantic. Volume 1: Introduction, Molluscs, Crustaceans, Hagfishes, Sharks, Batoid fishes and Chimaeras. Rome: FAO. p.562-571. (FAO Species Identification Guide for Fisheries Purposes and American Society of Ichthyologists and Herpetologists Special Publication No.5). McEACHRAN, J.D.; DUNN, K. & MIYAKE, T., 1996. Interrelationships of batoid fishes. In: STIASSNY, M.L.J.; PARENTI, L. & JOHNSON, G.D. (Eds.) Interrelationships of Fishes. San Diego: Academic Press. p.63-84. McEACHRAN, J.D. & FECHHELM, J.D., 1999. Fishes of the Gulf of Mexico. Volume 1: Myxiniformes to Gasterosteiformes. Austin: University of Texas Press. 1112p. MENNI, R.C. & STEHMANN, M.F.W., 2000. Distribution, environment and biology of batoid fishes off Argentina, Uruguay and Brazil. A review. Revista del Museu Argentino Ciencias Naturales, n.s., Buenos Aires, 2(1):69-109. MIRANDA RIBEIRO, A., 1907. Fauna brasiliensis (peixes). Tomo II. Desmobrânquios. Arquivos do Museu Nacional, Rio de Janeiro, 14:129-212, 19 pls. MIRANDA RIBEIRO, A., 1923. Fauna brasiliensis (peixes). Rio de Janeiro: Imprensa Nacional, Museu Nacional do Rio de Janeiro. 50p. MONKOLPRASIT, S., 1984. The cartilagenous fishes (class Elasmobranchii) found in Thai waters and adjacent waters. Bangkok: Kasetsart University. 175p. MÜLLER, J. & HENLE, F.G.J., 1841. Systematische Beschreibung der Plagiostomen. Berlin: Veit. 200p., 73pls. NISHIDA, K. & NAKAYA, K., 1988a. A new species of the genus Dasyatis (Elasmobranchii: Dasyatididae) from southern Japan and lectotype designation of D. zugei. Japanese Journal of Ichthyology, Tokyo, 35(2):115-123. NISHIDA, K. & NAKAYA, K., 1988b. Dasyatis izuensis, a new stingray from the Izu peninsula, Japan. Japanese Journal of Ichthyology, Tokyo, 35(3):227-235. NISHIDA, K. & NAKAYA, K., 1990. Taxonomy of the genus Dasyatis (Elasmobranchii, Dasyatididae) from the North Pacific. In: PRATT, H.L.; TANIUCHI, K. & GRUBER, S.H. (Eds.) Elasmobranchs as living resources. Advances in the biology, ecology, systematics and the status of the fisheries. Washington DC: United States Department of Commerce. p.327-346. (National Oceanic and Atmospheric Administration, Report 90, National Marine Fisheries Service). NOTARBARTOLO-DI-SCIARA, G. & BIANCHI, I., 1998. Guida degli squali e delle razze del Mediterraneo. Padova: Franco Muzzio Editore. 388p. QUEIROZ, E.L.; SOUZA FILHO, J.J. & SIMÕES, F.M., 1993. Estudo da alimentação de Dasyatis guttata (Bloch & Schneider, 1801), na áera de influência da estação ecológica Ilha do Medo, Bahia, Brasil. In: REUNIÃO DO GRUPO DE TRABALHO PESCA E PESQUISA DE TUBARÕES E ARRAIAS NO BRASIL, 6., Recife. Resumos..., Recife, p.28. REFI, S.M., 1975. Myliobatidae y Dasyatidae del litoral bonaerense de la República Argentina y estudio comparado del mixopterígio (Chondrichthyes, Myliobatoidea). Physis A, Buenos Aires, 34(88):121-136. ROBERTS, T.R. & KARNASUTA, J., 1987. Dasyatis laosensis, a new whiptailed stingray (family Dasyatidae), from the Mekong River of Laos and Thailand. Environmental Biology of Fishes, Dordrecht, 20(3):161-167. Bol. Mus. Nac., N.S., Zool., Rio de Janeiro, n.516, p.1-24, abr.2004 24 H.R.S.SANTOS & M.R.CARVALHO ROSENBERGER, L.J., 2001. Phylogenetic relationships within the stingray genus Dasyatis (Chondrichthyes: Dasyatidae). Copeia, Lawrence, 2001(3):615-627. SÉRET, B., 1990. Dasyatidae. In: LÉVÊQUE, C.; PAUGY, D. & TEUGELS, G.G. (Eds.) Faune des poissons d’eaux douces et saumâtres de l’Afrique de l’Ouest. Paris: ORSTOM, MRAC. p.62-75. SÉRET, B. & McEACHRAN, J.D., 1986. Catalogue critique des types de poissons du Muséum National d’Histoire Naturelle. Poissons Batoides (Chondrichthyes, Elasmobranchii, Batoidea). Bulletin du Muséum National d’Histoire Naturelle, Paris, 4(8):3-50. STEHMANN, M.F.W., 1981. Dasyatidae. In: FISCHER, W.; BIANCHI, G. & SCOTT, W.B. (Eds.) FAO species identification guides for fishery purposes. Eastern Central Atlantic. Fishing area 34, 47 (5). Rome: FAO. p.1-5. TANIUCHI, T. & ISHIHARA, H., 1990. Anatomical comparison of claspers of freshwater stingrays (Dasyatidae and Potamotrygonidae). Japanese Journal of Ichthyology, Tokyo, 37(1):10-16. TORTONESE, E., 1956. Leptocardia, Ciclostomata, Selachii. Bologna: Edizioni Calderini. 334p. WALLACE, J.H., 1967. The batoid fishes of the east coast of South Africa. Part II: manta, eagle, duckbill, cownose, butterfly and sting rays. South African Association for Marine Biological Research, Oceanographic Research Institute, Investigative Reports, Durban, 16:1-56. MUSEU NACIONAL Universidade Federal do Rio de Janeiro Quinta da Boa Vista, São Cristóvão 20940-040 – Rio de Janeiro, RJ, Brasil Impresso com apoio da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES Programa PROAP/2003 Impresso na Gráfica da UFRJ