Rasbora arundinata, Lumbantobing, Daniel N., 2014

Lumbantobing, Daniel N., 2014, Four new species of Rasbora of the Sumatrana group (Teleostei: Cyprinidae) from northern Sumatra, Indonesia, Zootaxa 3764 (1), pp. 1-25 : 6-10

Rasbora arundinata , new species

( Figures 2 A, 4A–C, 7A)

Rasbora lateristriata var. sumatrana (non Bleeker 1854): Weber & de Beaufort 1916. Rasbora lateristriata (non Bleeker 1854): Wirjoatmodjo 1987; Kottelat & Vidthayanon 1993. Rasbora sumatrana (non Bleeker 1852): Hadiaty 2005.

Rasbora cf. sumatrana (non Bleeker 1852): Lumbantobing 2010.

Holotype. MZB 17881 (ex. USNM 390034), female, 74.5 mm SL, Indonesia, Sumatra, Province of Nanggroe Aceh Darussalam, Kabupaten Aceh Singkil: Road from Subulussalam to Singkil, Lae Petal River, 02°31’76”N, 098°02’64”E, 21 July 2006, D. N. Lumbantobing, D. Rudaya, and N. M. Ray.

Paratypes. Indonesia, Sumatra: collected with holotype: MZB 17882 (ex. USNM 390034), 1, 67.8 mm SL; USNM 390034, 2, 64.5 and 68.5 mm SL. Province of Aceh: Kabupaten Gayo Lues: MZB 17885 (ex. USNM 390069), 1, 64.7 mm SL; USNM 390069, 1, 47.5 mm SL, Kampung Lintoh, a tributary of Tripa River, on the road from Takengon to Blangkejeren, 04°02’06”N, 097°20’33”E; D. N. Lumbantobing, R. K. Hadiaty, D. Rudaya, and N. M. Ray, 7 July 2006. Kabupaten Aceh Selatan: Kecamatan Kluet Timur: D. N. Lumbantobing, D. Rudaya and N. M. Ray: 15 July 2006: MZB 17884 (ex. USNM 390053), 8, 42.7–86 mm SL; USNM 390053, 7 (1 CS), 45.2– 85.2 mm SL, Lawe Mokap River, tributary of Kluet River, 03°09’96’’N, 097°23’90’’E; ZRC 53196 (ex. USNM 390053), 3, 49.7–76.0 mm SL; USNM 401462, 4, 43.0– 68.2 mm SL, Hari Pinem River (a tributary of Kluet River), 03°09’62N, 097°24’89”E; ZRC 53197, 2, 37.9–58.0 mm SL, Hari Pinem River (a tributary of Kluet River), 03°09’62N, 097°24’89”E. Kabupaten Aceh Singkil: MZB 17886, 5, 22.7–40.3 mm SL, road between Rimo and Singkil, Laicuk Bridge, tributary of Alas River, 02°19’29”N, 097°55’61”E, D. N. Lumbantobing, D. Rudaya and N. M. Ray, 21 July 2006. Kabupaten Aceh Tenggara: USNM 391607, 2, 54,6– 62.8 mm SL, Ketambe, Alas River, 03º41’91’’N, 097º38’74’’E, D. N. Lumbantobing, R. K. Hadiaty, D. Rudaya, and N. M. Ray, 2 July 2006. Province of Sumatera Utara (North Sumatra): MZB 17883, 2, 47.9–71.6 mm SL, Kabupaten Tapanuli Tengah, irrigation canal of Aek Pinangsori River (tributary of Batang Lumut River) on road between Sibolga and Batangtoru, 01°33’59’’N, 098°54’62’’E, approximately 46 m above sea level, D. N. Lumbantobing, D. Rudaya, N. M. Ray, and P. Simanjuntak, 4 August 2006.

Non-types. All from Indonesia: Sumatra: Province of Aceh: Kabupaten Aceh Barat: MZB 4646, 4, 71.1–85.9 mm SL, Krueng Ukam, Tadue, Kuala, A. Saim. Kabupaten Aceh Selatan: MZB 5656, 5, 77.0–80.0 mm SL, Alur Serembaning, Ruding Lanak, Sungai Alas di hilir Sungai Gelombang, Soetikno W., 20 Feb 1984; MZB 5658, 4, 64.5–99.9 mm SL, Sungai Alas, 5 km from hulu Gelombang, Soetikno W. and D. Hardjono, 3 Feb 1983. Kabupaten Aceh Singkil: MZB 17887, 1, 42.7, Dano, road between Gelombang and Subulussalam, small river under bridge, 02°41’42”N, 097°59’70”E; D. N. Lumbantobing et al. 18 July 2006.; USNM 390145, 1, 26.9 mm SL, same data as MZB 17887; USNM 406855, 1, 69.3 mm SL, fish market in Gelombang, D. N. Lumbantobing, D. Rudaya, and N. M. Ray, 19 July 2006; USNM 401463, 20 (7 CS), 43.8–85.6 mm SL, swamp draining to Lae Kumbi River (tributary of Alas River), 02º39’05’’N, 097º51’55’’E, D. N. Lumbantobing et al. 20 July 2006; ZMA 102.393, 10, 65.9–97.3 mm SL, Air Runding, Padang Benedenlanden, E. Jacobson, November 1913. Kabupaten Aceh Tenggara: MZB 4505, 17, 39.7–78.7 mm SL, Ketambe, Sungai Jamur Geuleu (65 km from Kutacane), I. Rachmatika, 7 Mar 1982; MZB 4516, 2, 47.5 and 50.2 mm SL, Ketambe, Sungai Alas, Ninik. S., 3 Mar 1982; MZB 4518, 26, 31.6–77.2 mm SL, Ketambe, Sungai Alas, Soetikno and D. Hardjono, 9 Mar 1982; USNM 404352, 3, 51.7–62.7 mm SL, fish market in Kutacane, D. N. Lumbantobing et al. 2 July 2006; USNM 401211, 1, 63.0 mm SL, Kampung Air Kelabu, Alas River near road between Kutacane and Blangkejeren, 03º42’69’’N, 097º38’02’’E, D. N. Lumbantobing, R. K. Hadiaty, D. Rudaya, and N. M. Ray, 2 July 2006. Kabupaten Aceh Tengah: MZB 5364, 4, 62.5–81.9 mm SL, Krueng Owaq, Kecamatan Lingge, D. Wowor, 26 Jan 1984. Kabupaten Nagan Raya: USNM 401210, 1, 34.1 mm SL, Seumayam River, 03º58’15’’N, 096º39’13’’E, D. N. Lumbantobing et al. 11 July 2006. Province of Sumatera Utara (North Sumatra): USNM 401209, 2, 16.2–20.7 mm SL, Kabupaten Tapanuli Selatan, Kecamatan Batang Toru, Desa Garoga, Aek Garoga River, 01°30’95”N, 098°59’39”E, D. N. Lumbantobing, D. Rudaya, and N. M. Ray, 25 July 2006; ZMA 102.395, 5, 59.3–66.2 mm SL, West Nias (Nias Island), Kleinoeg de Zwaan.

Diagnosis. Rasbora arundinata is distinguished from all congeners in having a unique black midlateral stripe overall forming a reed-leaf-like profile, which consists of: a subdorsal blotch that starts tapering anteriorly from the vertical through the dorsal-fin origin where its dorsal margin appears to be slightly crested, and the tapering extends further anteriorly reaching midhumeral region via a long pointed anterior tip; a midhumeral diffuse patch in which melanophores concentrate right below the subdorsal blotch and extends anteriorly in a somewhat diffuse fashion to reach the midhumeral region; and a posterior-portion stripe that terminates posteriorly at the area immediately dorsal to the anterior apex of the triangular basicaudal blotch. Rasbora arundinata can be distinguished further from its congeners by the combination of all the following characters listed in the description section of this species.

Description. General appearance shown in Fig. 2 A. Morphometric and meristic data given in Table 1. Dorsohypural distance equal to distance from dorsal-fin origin to area between vertical through anterior margin and posterior margin of eye. Limit between head and trunk indistinct in lateral view. Cephalic tubercles absent. Lateral line complete (all scales perforated; 24–26 + 3–5). Dorsal-fin origin over 13th lateral-line scale. Tip of adpressed pectoral fin barely reaching vertical through pelvic-fin insertion. Pelvic fin inserted below 12th lateral-line scale and distinctly anterior to vertical through dorsal-fin origin. Tip of adpressed pelvic fin extending past anal opening almost to anal-fin origin; in larger specimens reaching anal-fin origin. Anal-fin origin below 18th or 19th lateralline scale.

Coloration in alcohol. General body coloration in alcohol preservation shown in Fig. 2 A. Schematic lateral body pigmentation shown in Fig. 7 A. Lachrymal region superficially pigmented with scattered small melanophores more concentrated peripherally. Dusky gular pigmentation reaching posteriorly to vertical through rictus. Occipital region with two superficial lines and one deeply-embedded solid line in between. Post-opercular streak thick and prominent with dense melanophores; situated posterior to and running along pectoral girdle and reaching ventrally to axillary lobe of pectoral fin. Axillary lobe pigmented with more sparsely-distributed and stellate melanophores as far as subdistal portion. Mid-dorsal stripe one-fourth scale wide and extending from nape to dorsal part of caudal peduncle.

Rasbora arundinata Rasbora haru

n = 31 n = 25

Range Mean ± SD Range Mean ± SD Standard length (mm) 42.7–86.3 68.8 ± 14.2 26.5–80.3 56.7 ± 13.8 Percentage of standard length

Total length 135.0–142.7 139.2 ± 1.7 136.6–144.3 140.0 ± 1.7 Peripheral reticulation distinct and covering at maximum four longitudinal scale rows along dorsolateral portion of body. Basal reticulation distinct and covering up to five longitudinal scale rows and also dorsal scale row, with network of independent chevron-shaped bars. Peripheral and basal reticulation overlapping on first to fourth longitudinal scale rows and also on dorsal scale row. Black midlateral stripe prominent, more intense on central portion forming somewhat wedge-shaped subdorsal blotch, and overall forming reed-leaf-like profile. Stripe slightly angled anteroventrally and strongly tapering anteriorly until becoming obscure thin line reaching mid-humeral region. Stripe slightly attenuating posteriorly with ventral margin slightly ascending and extending to black basicaudal blotch. Axial streak posteriorly overlapping dorsal margin of black midlateral stripe, but streak separate from stripe in area above 12th or 13th lateral-line scale. Streak decreasing in intensity anteriorly until diffusing above 7th lateral-line scale. Longitudinal light area indistinct, most visible along area adjacent to posterodorsal portion of axial streak and black midlateral stripe, but covered with reticulation.

Deeply-embedded diamond-shaped black basicaudal blotch confluent anteromedially with black midlateral stripe. Blotch consisting two elements: basicaudal triangular patch and basicaudal spot. Basicaudal triangular patch confluent anteriorly with black midlateral stripe, originating posterior to hypural notch, and flaring posteriorly. In some specimens, triangular expansion not well-developed. Basicaudal spot confluent anteriorly with and appearing darker than triangular patch, and terminating anterior to medial sheath scale of caudal fin. Supranal pigmentation distinct appearing as a somewhat tear-shaped black patch smaller than pupil, originating slightly posterior to vertical through anal-fin origin, and terminating at vertical through base of third branched anal-fin ray. Subpeduncular pigmentation dusky, slightly decreasing in intensity anteriorly. Distal edge of caudal fin pigmented with scattered melanophores resulting in narrow dusky striped margin.

Coloration in life. Ground coloration of dorsolateral surface of head and body pale brown with slightly silvery sheen, ventral surface barely pigmented with whitish reflective guanine ( Fig. 4 A–C). Dorsum of head largely dusky, with scattered yellowish reflective patches and streaks on snout, lateral-line canals, meningeal layer, and supraorbital. Anterodorsomedial portions of operculum and upper end of gill slit with reflective yellowish patches ( Fig. 4 C). Reflective midlateral stripe metallic yellowish, juxtaposed ventrally by black midlateral stripe. Reflective stripe prominent on anterior portion of trunk, continuously extending from humeral region, slightly widening posteriorly until above 9th or 10th lateral-line scale, then tapering posteriorly until appearing as thin reflective line below dorsal fin, and terminating at hypural notch ( Fig. 4 A–B). Black peripheral reticulation bordered anteriorly by metallic yellowish sheen overall appearing as reticulated pattern of yellowish reflective crescents. All fins hyaline. Dorsal and caudal fins with yellowish sheen on subdistal portion of branched rays.

Habitat and distribution. The specimens of Rasbora arundinata were collected in various types of habitat, such as gravel-bottomed mountain streams, moderate-flowing turbid rivers, and muddy backwater pools. This species is known from the Tripa Jaya, Kluet, and Alas rivers that flow into the Indian Ocean in the southern part of northwestern Sumatra ( Fig. 8 ). Rasbora arundinata was collected sympatrically with Rasbora api , R. kluetensis (only in the Kluet River), R. jacobsoni , and R. truncata (only in the Alas River).

Etymology. The specific name, arundinata , an adjective from the Latin ‘ arundo ’ for reed, refers to the shape of the black midlateral stripe of the species appearing like a reed leaf.

Figures

FIGURE 2. (A) Rasbora arundinata, holotype, MZB 17881, 74.5 mm SL, female; (B) Rasbora haru, holotype, MZB 17888, 65.4 mm SL, female; (C) Rasbora maninjau, holotype, MZB 17890, 66.9 mm SL, male; (D) Rasbora bindumatoga, holotype, MZB 17889, 47.1 mm SL, female. Bars equal 1 cm.

FIGURE 4. Photographs of living specimen of Rasbora arundinata, USNM 391607 (paratype).

FIGURE 7. Schematic drawing of left lateral view showing the three primary diagnostic lateral pigmentation characteristics of members of the Hosii subgroup: (A) Rasbora arundinata; (B) Rasbora haru; (C) R. bunguranensis; (D) R. notura.

FIGURE 8. Distribution of species of the Sumatrana group in northwestern Sumatra and adjacent regions: Rasbora arundinata (blue diamonds), Rasbora haru (green circles), Rasbora maninjau (yellow star), Rasbora bindumatoga (red asterisks), and R. vulgaris (magenta squares). Symbols with black outline are the localities of holotypes. One filled symbol may represent more than one locality.