Editorial Type:
Article Category: Research Article
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Online Publication Date: 17 Dec 2010

Four New Species of the Rasbora trifasciata-Group (Teleostei: Cyprinidae) from Northwestern Sumatra, Indonesia

Page Range: 644 – 670
DOI: 10.1643/CI-09-155
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Abstract

Four new cyprinid species of the Rasbora trifasciata-group, Rasbora api, R. nodulosa, R. kluetensis, and R. truncata, are described from northwestern Sumatra, Indonesia. Rasbora api is distinguished from its congeners in the R. trifasciata-group by an anteriorly tapering black midlateral stripe extending posteriorly along the flank from the first lateral-line scale system and terminating at a slightly wider black basicaudal spot on the caudal-fin base, and stout conical cephalic tubercles with basal portion bearing microgranules (Type A tubercles). Rasbora nodulosa is distinguished from its congeners in the species group by having nodular and smaller cephalic tubercles (Type D tubercles). Rasbora kluetensis is distinguished from its congeners in the species group by the conical cephalic tubercles with a somewhat protruded base bearing microridges (Type E tubercles). Rasbora truncata differs from its congeners in the species group by a combination of meristic, pigmentary, and tuberculation features, and details of the lateral line system. Other members of the R. trifasciata-group in the region, Rasbora meinkeni and R. tobana, are redescribed. Rasbora tobana is resurrected. Three new areas of endemism in northwestern Sumatra are proposed based on the distributions of three new endemic species: the Tripa District represented by R. nodulosa, the Kluet District represented by R. kluetensis, and the Alas District represented by R. truncata.

Resumen

Empat jenis baru ikan anggota famili Cyprinidae yang berasal dari wilayah Barat Daya Sumatera, Rasbora api, R. nodulosa, R. kluetensis, dan R. truncata, yang termasuk dalam kelompok jenis R. trifasciata, telah dideskripsikan. Rasbora api dapat dibedakan dari semua kerabat semarganya anggota kelompok jenis R. trifasciata lainnya berdasarkan adanya: pita gelap di sisi samping tengah badan yang memanjang mulai dari sisik pertama gurat sisi dan diakhiri oleh sebuah noktah hitam di pangkal ekor, serta tuberkel sefalik yang tinggi kukuh mengerucut dengan dasaran yang ber-mikrogranula (tuberkel golongan A). Rasbora nodulosa dapat dibedakan dari semua anggota kelompok jenisnya yang lain berdasarkan adanya: tuberkel sefalik berbentuk nodula yang lebih kecil (tuberkel golongan D). Rasbora kluetensis dapat dibedakan dari semua anggota kelompok jenisnya yang lain berdasarkan adanya tuberkel sefalik dengan dasaran yang menyembul dan memiliki punggungan renik (tuberkel golongan E). Rasbora truncata dapat dibedakan dari semua anggota kelompok jenisnya yang lain berdasarkan perpaduan yang khas antara ciri-ciri meristik, pigmentasi, dan tuberkulasi, serta ciri terinci dari sistem gurat sisi. Anggota-anggota kelompok jenis R. trifasciata yang tersebar di kawasan tersebut lainnya, yaitu R. meinkeni dan R. tobana, telah dideskripsikan ulang. Selain itu, status taksonomik R. tobana telah dipulihkan kembali. Tiga wilayah endemisme baru di Barat Daya Sumatera diajukan berdasarkan pola persebaran tiga jenis endemik anggota grup R. meinkeni tersebut, yaitu: Distrik Tripa diwakili oleh R. nodulosa, Distrik Kluet diwakili oleh R. kluetensis, dan Distrik Alas diwakili oleh R. truncata. (Bahasa Indonesia)

Copyright: 2010 by the American Society of Ichthyologists and Herpetologists
Fig. 1
Fig. 1

Left lateral views of body showing: (A) general body pigmentation; (B) morphometric measurements and schematic body scalation. Numbers on scales (1–5) refer to the order of longitudinal scale rows; ABL  =  anal base length; BCS  =  basicaudal spot; BR  =  basal reticulation; CPD  =  caudal peduncle depth; CPL  =  caudal peduncle length; DBL  =  dorsal base length; DD  =  dorsal fin depth; DHyL  =  dorsohypural distance; DLS  =  dorsolateral stripe; ED  =  eye diameter; HD  =  head depth; HL  =  head length; LCL  =  lower caudal lobe length; LLA  =  light longitudinal area; MCL  =  median caudal length; MLS  =  midlateral stripe; MOS  =  midopercular stripe; PCB  =  precaudal blotch; PD  =  predorsal length; POP  =  postopercular pigmentation; PR  =  peripheral reticulation; PrA  =  preanal length; PrPv  =  prepelvic length; PtL  =  pectoral fin length; PvL  =  pelvic fin length; SAP  =  supraanal pigmentation; SL  =  standard length; SnL  =  snout length; SPS  =  subpeduncular streak; TL  =  total length; UCL  =  upper caudal lobe length.

Fig. 2
Fig. 2

Left lateral view of portion of body above rear of pectoral fin elaborately showing types of body pigmentation: dusky dorsolateral background pigmentation, streak, stripes, and reticulated patterns. AS  =  axial streak; BR  =  basal reticulation; DLR  =  dorsolateral region; DLS  =  dorsolateral stripe; IZ  =  immaculate zone; LLA  =  light longitudinal area; MLR  =  midlateral region; MLS  =  midlateral stripe; PF  =  pectoral fin; PR  =  peripheral reticulation; VLR  =  ventrolateral region.

Fig. 3
Fig. 3

Left lateral view of schematized cranium showing infraorbitals, supraorbitals, cephalic lateral line canals, and dermosphenotic region. (A) Rasbora api, USNM 390330, 33.4 mm SL; (B) Rasbora meinkeni, USNM 390223, 30.4 mm SL; (C) Rasbora tobana, USNM 193041, 33.5 mm SL; (D) Rasbora nodulosa, USNM 391743, 34.2 mm SL; (E) Rasbora kluetensis, USNM 391747, 31.7 mm SL; (F) Rasbora truncata, USNM 391745, 32.2 mm SL. 1IC  =  first infraorbital concavity on its posterior margin; 1IP  =  first infraorbital process on dorsoposterior tip; DmC  =  dorsomedial branching of supraorbital canal on posterior frontal; LDF  =  large dilatator fossa; LSo  =  large supraorbital (with narrow gap between its posterior tip and fifth infraorbital); SpE  =  sphenotic exposure (above supraorbital canal). Each bar equals 0.5 cm.

Fig. 4
Fig. 4

Scanning electron microscope images of cephalic tubercles and cranial superficial neuromasts. Rasbora api, USNM 391737, 34.1 mm SL, male: type A tubercles (A1–A3), type I cranial neuromasts (A4); Rasbora meinkeni, USNM 390223, 25.5 mm SL, male: type B tubercles (B1–B3), type II cranial neuromasts (B4); Rasbora tobana, USNM 193001, 27.6 mm SL, male: type C tubercles (C1–C3), type II cranial neuromasts (C4); Rasbora nodulosa, MZB 16468, 26.9 mm SL, male: type D tubercles (D1–D3), type III cranial neuromasts (D4); Rasbora kluetensis, USNM 391747, 24.9 mm SL, male: type E tubercles (E1–E3), type I cranial neuromasts (E4); Rasbora truncata, USNM 391745, 25.5 mm SL, male: type B tubercles (F1–F3), type IV cranial neuromasts (F4).

Fig. 5
Fig. 5

(A) Rasbora api, new species, holotype, MZB 16457, 45.6 mm SL, female; (B) Rasbora meinkeni, USNM 390223, 26.2 mm SL, female; (C) Rasbora tobana, USNM 390141, 29.9 mm SL, female. Each bar equals 1 cm.

Fig. 6
Fig. 6

Photographs of living specimes: (A) Rasbora api, MZB 16687; (B) Rasbora meinkeni, USNM 390223, photo by R. Hadiaty; (C) Rasbora tobana, USNM 390318; (D) Rasbora nodulosa, MZB 16468.

Fig. 7
Fig. 7

Left lateral view of head showing close up of lachrymal pigmentation (A, C), ventrolateral margin of upper jaw (B, D), and ventral projection of dentary articulation (C: arrow). (A) Rasbora api, MZB 16458, 42.7 mm SL, with lachrymal peripherally pigmented and unpigmented central area, also present in R. nodulosa and R. truncata; (B) schematized ventrolateral margin of upper jaw with lachrymal groove in R. api and R. tobana; (C) R. meinkeni, MZB 16689, 25.9 mm SL, with lachrymal uniformly pigmented, also present in R. tobana and R. kluetensis; (D) schematized ventrolateral margin of upper jaw with shallow lachrymal groove in R. meinkeni, R. nodulosa, R. kluetensis, and R. truncata. LG  =  lachrymal groove. Each bar equals 1 mm.

Fig. 8
Fig. 8

Left lateral view of caudal peduncle elaborately showing position of axial streak relative to black midlateral stripe posteriorly. (A) Axial streak traversing black midlateral stripe; (B) axial streak barely traversing black midlateral stripe, but bordering dorsal margin of stripe. AS  =  axial streak.

Fig. 9
Fig. 9

Distribution of species of Rasbora trifasciata-complex in northwestern Sumatra: Rasbora api (diamonds), R. meinkeni (five-pointed stars), R. tobana (ten-pointed stars), R. nodulosa (squares), R. kluetensis (hexagrams), and R. truncata (circles). Filled symbols are the locality of holotype. One symbol may represent more than one locality.

Fig. 10
Fig. 10

(A) Rasbora nodulosa, new species, holotype, MZB 16465, 34.6 mm SL, female; (B) Rasbora kluetensis, new species, holotype, MZB 16470, 30.9 mm SL, female; (C) Rasbora truncata, new species, holotype, MZB 16678, 26.6 mm SL, male. Each bar equals 1 cm.

Contributor Notes

1 Department of Biological Sciences, The George Washington University, 2023 G Street NW, Lisner Hall 340, Washington, D.C. 20052, and Division of Fishes, Smithsonian Institution, National Museum of Natural History, Washington, D.C. 20013; E-mail: dntobing@gwmail.gwu.edu

Associate Editor: D. Buth.

Received: 19 Aug 2009
Accepted: 12 Jul 2010
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