63 (3): 277 – 281

© Senckenberg Gesellschaft für Naturforschung, 2013. 20.12.2013

A new killifish of the from the upper Paraná river basin, Brazil (: )

Wilson J. E. M. Costa

Laboratório de Sistemática e Evolução de Peixes Teleósteos, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Caixa Postal 68049, CEP 21944-970, Rio de Janeiro, Brasil; wcosta(at)acd.ufrj.br

Accepted 01.xi.2013. Published online at www.senckenberg.de/vertebrate-zoology on 18.xii.2013.

Abstract Melanorivulus leali, new species, from the Grande river drainage, south-eastern Brazil, is described. It differs from all other congeners by possessing a unique colour pattern, comprising red dots on body side arranged in chevron shaped rows, a broad dark grey stripe along the ZKROHÀDQNÀDQNOLJKWEOXHLQPDOHVGRUVDODQGYHQWUDOSRUWLRQVRIWKHFDXGDO¿QOLJKWRUDQJLVKUHGLQPDOHVFRQVSLFXRXVRUDQJLVKUHG EDUVRQWKHPLGGOHRIWKHFDXGDO¿QLQPDOHVDQGGRUVDOSRUWLRQRIWKHFDXGDO¿QEDVHZLWKDVPDOOYHUWLFDOO\HORQJDWHGEODFNVSRW7KH presence of a black bar on the anterior and another on the posterior portion of the iris almost in contact with the pupil and the shape of the FKHYURQOLNHURZVRIUHGVSRWVRQWKHÀDQNLQZKLFKWKHDQJOHLVSODFHGRQWKHPLGOLQHRIWKHÀDQNLQGLFDWHWKDWM. leali is more closely UHODWHGWRFRQJHQHUVHQGHPLFWRWKH3DUDQi3DUDJXD\ULYHUV\VWHPWKDQWRFRQJHQHUVHQGHPLFWRWKH$PD]RQDVULYHUEDVLQ7KLV¿UVWUHFRUG of the genus Melanorivulus from the Grande river drainage suggests that it may have formerly occupied a larger region of this basin, pres- ently under severe process of deforestation and aquatic habitat decline.

Key words Biodiversity, conservation, Grande river, Neotropical region, .

Introduction

Melanorivulus COSTA, 2006 is a genus of small killi- form the main course of the Paraná river, was sent for ¿VKHVLQKDELWLQJVKDOORZIUHVKZDWHUKDELWDWVRIFHQWUDO study by FABIANO LEALLQ7KLVPDWHULDOZDVSUH- northern and north-eastern South America (COSTA, 2011). OLPLQDULO\LGHQWL¿HGDVM. zygonectes (MYERS, 1927) by It comprises over 50 species and its greatest species di- WKHRYHUDOOVLPLODULW\LQFRORXUSDWWHUQ¿QPRUSKRORJ\ versity is concentrated in the region encompassing the morphometric and meristic data, despite M. zygonectes upper Paraná and upper Araguaia river basins (COSTA, EHLQJ HQGHPLF WR DQ DUHD RI WKH 7RFDQWLQV ULYHU EDVLQ 2005, 2006, 2007, 2008a – c, 2013). Records for the about 900 km distant from the that locality in the Grande Paraná river basin include numerous localities in the river drainage. After recently obtaining larger collec- Paranaiba river drainage and some localities associated tions of M. zygonectes from its the type locality region to the western part of the middle Paraná basin (COSTA, as comparative material, it was possible to recognise the 2005, 2007, 2008a – c). Material collected in the Grande material collected in the Grande river drainage as a new river drainage, a large tributary coming from the East to species, which is herein described.

ISSN 1864-5755 277 W.J.E.M. Costa: A new Melanorivulus from the upper Paraná river basin

Material and methods Table 1. Morphometric data of Melanorivulus leali.

holotype paratypes male males (4) females (5) Material is deposited in UFRJ, Instituto de Biologia, Standard length (mm) 28.8 24.7 – 29.3 24.7 – 27.9 Universidade Federal do Rio de Janeiro, Rio de Janeiro. Percent of standard length Morphological characters used in the description below Body depth 21.4 19.9 – 20.9 19.3 – 20.4 ZHUHREWDLQHGIURPVSHFLPHQV¿[HGLQIRUPDOLQMXVWDI- Caudal peduncle depth 12.8 12.3 – 13.0 11.7 – 12.8 ter collection, for a period of about ten days, and then Predorsal length 74.9 72.6 – 75.8 73.8 – 77.1 transferred to 70 % ethanol. Descriptions of colour pat- Prepelvic length 55.1 52.1 – 54.7 52.9 – 55.3 terns were based on photographs of the both known Length of dorsal-fin base 11.9 11.1 – 12.1 11.2 – 12.3 specimens taken in small aquaria a few days after col- Length of anal-fin base 20.0 16.7 – 21.5 16.8 – 21.2 lection. Measurements and counts follow COSTA (1995). Caudal-fin length 36.1 36.1 – 37.6 34.1 – 36.8 Measurements are presented as percentages of standard Pectoral-fin length 21.4 20.2 – 21.5 18.3 – 21.2 length (SL), except for those related to head morphology, Pelvic-fin length 10.8 9.1 – 12.1 8.7 – 9.8 which are expressed as percentages of head length. Fin- Head length 25.4 24.3 – 25.5 24.0 – 26.4 ray counts include all elements. Number of vertebrae and Percent of head length gill-rakers were recorded only from the cleared and stained Head depth 69.6 66.9 – 71.8 64.9 – 70.3 specimen; the compound caudal centrum was counted as Head width 84.2 75.8 – 81.1 76.0 – 80.1 DVLQJOHHOHPHQW7KHRVWHRORJLFDOSUHSDUDWLRQZDVPDGH Snout length 14.5 13.6 – 15.0 12.5 – 13.7 according to TAYLOR & VAN DYKE  7HUPLQRORJ\ Lower jaw length 21.1 19.2 – 21.8 18.3 – 21.2 Eye diameter 30.0 30.0 – 33.1 30.9 – 34.9 for cephalic neuromast series COSTA  7KHDEEUHYL- ation c&s means specimens cleared and stained for bone and cartilage. Delimitation of species is according to the methodology of the Population Aggregation Analysis on the posterior portion of the iris almost in contact with (DAVIS & NIXON, 1992), in which species are delimited by the pupil. a unique combination of morphological character states. Comparisons focus on characters extracted from the col- Description. 0RUSKRPHWULF GDWD DSSHDU LQ 7DEOH RXU SDWWHUQ RI OLYLQJ LQGLYLGXDOV MXVW DIWHU FROOHFWLRQV 'RUVDOSUR¿OHDERXWVWUDLJKWIURPVQRXWWRGRUVDO¿QRUL- which have been demonstrated to be highly informative JLQSRVWHULRUO\LQFOLQHGDQGQHDUO\VWUDLJKWRQGRUVDO¿Q WR LQIHU VSHFLHV OLPLWV LQ DSORFKHLORLG NLOOL¿VKHV e.g., EDVHDQGFDXGDOSHGXQFOH9HQWUDOSUR¿OHJHQWO\FRQYH[ COSTA et al., 2012). IURPORZHUMDZWRHQGRIDQDO¿QEDVHDERXWVWUDLJKWRQ caudal peduncle. Body slender, subcylindrical anteriorly, slightly deeper than wide, to compressed posteriorly. *UHDWHVWERG\GHSWKDWYHUWLFDOMXVWLQIURQWWRSHOYLF¿Q base. Jaws short, snout blunt. Melanorivulus leali spec. nov.  ([WUHPLW\RIGRUVDODQGDQDO¿QVURXQGHG&DXGDO¿Q URXQGHG VOLJKWO\ ORQJHU WKDQ GHHS 3HFWRUDO ¿Q URXQG- )LJV±7DEOH ed, posterior margin reaching vertical at about 90 % of OHQJWKEHWZHHQSHFWRUDO¿QDQGSHOYLF¿QEDVHV3HOYLF ¿QVPDOOWLSUHDFKLQJEHWZHHQDQXVDQGEDVHRIVWDQDO Holotype: UFRJ 6866, 28.8 mm SL, male; Brazil: Estado de São 3DXOR0XQLFtSLRGH6HUUD$]XOVWUHDPWULEXWDU\RI7DPDQGXD]LQKR ¿QUD\3HOYLF¿QEDVHVPHGLDOO\LQFRQWDFW'RUVDO¿Q river, Pardo river drainage, itself part of Grande river drainage, RULJLQ RQ YHUWLFDO WKURXJK EDVH RI WK RU WK DQDO¿Q upper Paraná river basin, 21°20‘00“S 47°34‘20“, altitude about UD\VHFRQGSUR[LPDOUDGLDORIGRUVDO¿QEHWZHHQQHXUDO 700 m; M. MARTINS, 22 July 2007. VSLQHVRIWKDQGVWYHUWHEUDH¿UVWSUR[LPDOUDGLDORI Paratypes: UFRJ 6539, 9 males, 24.6 – 29.3 mm SL, 10 females, DQDO¿QEHWZHHQSOHXUDOULEVRIWKDQGWKYHUWHEUDH 19.0 – 32.0 mm SL; UFRJ 6540, 2 males, 23.0 – 24.4 mm SL, 2 fe- 'RUVDO¿Q UD\V ± DQDO¿Q UD\V ± FDXGDO¿Q males, 22.4 – 27.6 mm SL (c&s); collected with the holotype. UD\V±SHFWRUDO¿QUD\VSHOYLF¿QUD\V Scales small, cycloid. Body and head entirely scaled, Diagnosis. Melanorivulus leali is distinguished from except anterior ventral surface of head. Body squama- all other congeners by the following character states in WLRQH[WHQGLQJRYHUDQWHULRURIFDXGDO¿QEDVHQR combination: red dots on body side arranged in chevron VFDOHVRQGRUVDODQGDQDO¿QEDVHV)URQWDOVTXDPDWLRQ VKDSHG URZV ZLWK DQJOH RQ WKH PLGOLQH RI WKH ÀDQN D F-patterned; E-scales not overlapping medially; scales EURDGGDUNJUH\VWULSHDORQJWKHZKROHÀDQNÀDQNOLJKW arranged in regular circular pattern around A-scale with- blue in males, dorsal and ventral portions of the caudal out exposed margins; transverse row of scales anterior to ¿QOLJKWRUDQJLVKUHGLQPDOHVFRQVSLFXRXVRUDQJLVKUHG H-scale. Five supraorbital scales. Longitudinal series of EDUVRQWKHPLGGOHRIWKHFDXGDO¿QLQPDOHVGRUVDOSRU- scales 32 – 35; transverse series of scales 7; scale rows WLRQRIWKHFDXGDO¿QEDVHZLWKDVPDOOYHUWLFDOO\HORQJDW- DURXQGFDXGDOSHGXQFOH1RFRQWDFWRUJDQVRQÀDQN ed black spot, and a black bar on the anterior and another DQG¿QV

278 VERTEBRATE ZOOLOGY — 63 (3) 2013

Fig. 1. Melanorivulus leali, UFRJ 6866, holotype, male, 28.8 mm SL: Brazil: São Paulo: Serra Azul.

Fig. 2. Melanorivulus leali, UFRJ 6539, paratype, female, 27.9 mm SL: Brazil: São Paulo: Serra Azul.

Cephalic neuromasts: supraorbital 3 + 3, parietal 1, ing chevron-like marks anteriorly directed with angle on anterior rostral 1, posterior rostral 1, infraorbital 1 + 11 – PLGOLQHRIÀDQN'RUVXPOLJKWEURZQZLWKGDUNEURZQ 12 + 1, preorbital 2, otic 1, post-otic 2, supratemporal 1, GRWV9HQWHUZKLWH8SSHUMDZOLJKWJUH\ORZHUMDZGDUN median opercular 1, ventral opercular 1 – 2, preopercu lar grey to black; light blue iridescence on sub-orbital re- 2 + 4, mandibular 3 + 1, lateral mandibular 2, pa ra man di- gion, golden on ventral part of opercle. Iris pale yellow, bular 1. Lateral line interrupted, alternating sets of 3 – 4 with broad dark brown to black bar on anterior and pos- VFDOHVZLWKRQHQHXURPDVWDQGZLWKRXWQHXURPDVWV7ZR WHULRUSRUWLRQVFORVHWRSXSLO'RUVDO¿QOLJKWEOXLVKJUH\ QHXURPDVWVRQFDXGDO¿QEDVH to pale yellow on distal portion, with short transverse red Basihyal subtriangular, greatest width about 45 – 50 % VWULSHVRQSRVWHULRUUHJLRQ$QDO¿QOLJKWEOXHZLWKUHG of length; basihyal cartilage about 20 % of total length dots on basis, pale yellow on middle and distal portion. of basihyal. Six branchiostegal rays. Second pharyngo- &DXGDO¿QRUDQJLVKUHGRQGRUVDODQGYHQWUDOSRUWLRQV EUDQFKLDOWHHWKDEVHQW*LOOUDNHUVRQ¿UVWEUDQFKLDODUFK bluish hyaline with vertical rows of orangish red dots on 1 + 7. Vomerine teeth 1 – 2. Dermosphenotic present. Ven- PLGGOH3HFWRUDO¿QVK\DOLQH3HOYLF¿QV\HOORZLVKK\D- WUDOSURFHVVRISRVWWHPSRUDODEVHQW7RWDOYHUWHEUDH± line. 32. Females. Similar to males, except by absence of red PDUNVRQXQSDLUHG¿QVGLVWDOPDUJLQRIGRUVDODQGDQDO Colouration. 0DOHV6LGHRIKHDGDQGÀDQNOLJKWEOXH ¿QVZKROHPDUJLQRIFDXGDO¿QDQGDQWHULRUPDUJLQRI with broad dark grey mid-lateral stripe between postor- SHOYLF¿QGDUNJUH\WREODFNVPDOODQGFDXGDO¿QSDOH ELWDOUHJLRQDQGFDXGDO¿QEDVHREOLTXHURZVRIUHGGRWV yellow with 5 – 6 dark grey to black bars and dorsally RQÀDQNPRUHFRQFHQWUDWHGRQFDXGDOSHGXQFOHIRUP- HORQJDWHGEODFNVSRWRQGRUVDOSRUWLRQRI¿QEDVH

279 W.J.E.M. Costa: A new Melanorivulus from the upper Paraná river basin

Distribution. Known only from the type locality, a small Acknowledgements stream of the Grande river drainage, upper Paraná river basin, south-eastern Brazil. 7KDQNV DUH GXH WR )DELDQR /HDO DQG 0D\OHU 0DUWLQV IRU VHQG- Etymology. 7KHQDPHleali is honour of FABIANO LEAL ing material for study, which was supported by CNPq (Conselho IRUKLVGHGLFDWLRQLQEUHHGLQJDSORFKHLORLGNLOOL¿VKHVDQG 1DFLRQDOGH'HVHQYROYLPHQWR&LHQWt¿FRH7HFQROyJLFR0LQLVWpULR for providing material of the new species. GH &LrQFLD H 7HFQRORJLD  DQG )$3(5- )XQGDomR GH$PSDUR j Pesquisa do Estado do Rio de Janeiro).

Discussion References

COSTA, W.J.E.M.   3HDUO NLOOL¿VKHV ± WKH &\QROHELDWLQDH 7KHGHVFULSWLRQRIM. leali FRQVWLWXWHVWKH¿UVWUHFRUGRID V\VWHPDWLFV DQG ELRJHRJUDSK\ RI WKH QHRWURSLFDO DQQXDO ¿VK rivulid for the Grande river drainage, which with a course subfamily. 1HSWXQH&LW\7)+S about 1,100 km long is one of the most important tribu- COSTA, W.J.E.M. (2001):7KHQHRWURSLFDODQQXDO¿VKJHQXVCyno- WDULHVRIWKHXSSHU3DUDQiULYHUEDVLQ7KLVQHZUHFRUGIRU lebias (Cyprinodontiformes: Rivulidae): phylogenetic relation- the genus suggests that Melanorivulus may have had a ships, taxonomic revision and biogeography. – Ichthyological larger geographical distribution in the past along the sev- Exploration of Freshwaters, 12: 333 – 383. eral tributaries of the Grande river. However, this region COSTA, W.J.E.M.  6HYHQQHZVSHFLHVRIWKHNLOOL¿VKJHQXV have been intensively deforested in the last 200 years, (Cyprinodontiformes: Rivulidae) from the Paraná, Pa- today resting rare vestiges of the original vegetation, a ra guay and upper Araguaia river basins, central Brazil. – Neo- process greatly affecting the integrity of aquatic habitats. tropical Ichthyology, 3: 69 – 82. Melanorivulus leali is distinguished from M. zygon- COSTA, W.J.E.M. (2006): Rivulus kayapo QVS 7HOHRVWHL&\SULQR ectes E\WKHIRUPHUKDYLQJÀDQNOLJKWEOXHLQPDOHV YV GRQWLIRUPHV 5LYXOLGDH  D QHZ NLOOL¿VK IURP WKH VHUUD GRV pale grey, without iridescent colours), conspicuous red &DLDSyV XSSHU ULR$UDJXDLD EDVLQ %UD]LO ± =RRWD[D 1368: EDUV RQ FDXGDO ¿Q LQ PDOHV YV YHUWLFDO URZV RI IDLQW 49 – 56. red dots, sometimes forming pale bars), depth of dark COSTA, W.J.E.M. (2007): Rivulus illuminatus, DQHZNLOOL¿VKIURP JUH\VWULSHRQÀDQNDERXWKDOIERG\GHSWK YVDERXWRQH WKHVHUUDGRV&DLDSyVXSSHUULR3DUDQiEDVLQ%UD]LO 7HOHRVWHL third), and caudal spot in females often almost incon- Cyprinodontiformes: Rivulidae). – Ichthyological Exploration spicuous, vertically elongated and highly overlapped by of Freshwaters, 18: 193 – 198. DQWHULRUFDXGDO¿QEDU YVDOZD\VFRQVSLFXRXVKRUL]RQ- COSTA, W.J.E.M. (2008a): A new species of Rivulus from the Claro WDOO\HORQJDWHG 7ZRRWKHUGHWDLOVRIWKHFRORXUSDWWHUQ river drainage, upper Paraná river basin, central Brazil, with re- indicate that M. leali is more closely related to species description of R. pinima and R. vittatus (Cyprinodontiformes: endemic to the Paraguay and Paraná river basins than to Rivulidae). – Ichthyological Exploration of Freshwaters, 18: M. zygonectes: there is a black bar on the anterior and an- 313 – 323. other on the posterior portion of the iris almost in contact COSTA, W.J.E.M. (2008b): Rivulus formosensis, a new aplocheiloid to the pupil (vs. anterior and posterior portion of the pupil NLOOL¿VKIURPWKHXSSHU&RUUHQWH5LYHUGUDLQDJHXSSHU3DUDQi dark, but not forming distinctive bars close to the pupil River basin, central Brazil (Cyprinodontiformes: Rivulidae). – in M. zygonectes) and red dots on body side arranged in Ichthyological Exploration of Freshwaters, 19: 85 – 90. FKHYURQVKDSHGURZVZLWKDQJOHRQWKHPLGOLQHRIÀDQN COSTA, W.J.E.M. (2008c): Rivulus giarettai D QHZ NLOOL¿VK IURP YVDQJOHRQWKHYHQWUDOSDUWRIWKHÀDQN  the Araguari River drainage, upper Paraná River basin, Brazil It is possible that M. dapazi, endemic to the Paraguay (Cyprinodontiformes: Rivulidae). – Ichthyological Exploration river basin (COSTA, 2005) is the closest relative of M. of Freshwaters, 19: 91 – 95. leali. Both species share a broad dark grey stripe on the COSTA, W.J.E.M. (2011): Phylogenetic position and taxonomic sta- SRVWHULRUSDUWRIWKHÀDQNDQGUHGSLJPHQWDWLRQRQWKH tus of , , , Laimo- FDXGDO¿QLQPDOHVMelanorivulus leali is distinguished semion and Melanorivulus (Cyprinodontiformes: Rivulidae). – from M. dapazi by the former having oblique rows of red Ichthyological Exploration of Freshwaters, 22: 233 – 249. GRWVRQWKHÀDQN YVEDUV DEVHQFHRIDGDUNRUDQJLVK COSTA, W.J.E.M.  7ZRQHZVSHFLHVRIMelanorivulus from UHGVWULSHRQWKHGLVWDOPDUJLQRIWKHDQDO¿QLQPDOHV YV WKH &DLDSyV KLOO XSSHU$UDJXDLD ULYHU EDVLQ %UD]LO &\SUL SUHVHQFH DQGFDXGDO¿QOLJKWRUDQJLVKUHGRQGRUVDODQG no dontiformes: Rivulidae). – Ichthyological Exploration of ventral portions (vs. whole marginal zone dark orangish Fresh waters, 23: 211 – 218. red with black outline).

280 VERTEBRATE ZOOLOGY — 63 (3) 2013

COSTA, W.J.E.M.; AMORIM, P.F. & MATTOS, J.L.O. (2012): Species TAYLOR, W.R. & VAN DYKE, G.C. (1985): Revised procedures for GHOLPLWDWLRQLQDQQXDONLOOL¿VKHVIURPWKH%UD]LOLDQ&DDWLQJD VWDLQLQJ DQG FOHDULQJ VPDOO ¿VKHV DQG RWKHU YHUWHEUDWHV IRU the +\SVROHELDVÀDYLFDXGDWXV complex (Cyprinodontiformes: bone and cartilage study. – Cybium, 9: 107 – 109. Rivulidae): implications for taxonomy and conservation. – Systematics and Biodiversity, 10: 71 – 91. HOEDEMAN, J.J.  7KHIURQWDOVFDODWLRQSDWWHUQLQVRPHJURXSV of toothcarps (Pisces, Cyprinodontiformes). – Bulletin of Aqua- tic Biology, 1: 23 – 28.

281