Rasbora maninjau, 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 : 11-14

Rasbora maninjau , new species

Figures 2 C, 5A–B, 9B

Rasbora lateristriata var. sumatrana (non Bleeker, 1854): Weber & Beaufort 1916. Rasbora lateristriata (non Bleeker, 1854): Kottelat & Vidthayanon 1993.

Holotype. MZB 17890, 66.9 mm SL, Indonesia, Province of Sumatera Barat (West Sumatra), Kabupaten Agam, Kecamatan Tanjung Raya, by Hotel Danau Maninjau , 6 August 2006.

Paratypes. Same data as holotype: MZB 21120, 1, 57.0 mm SL; USNM 406859, 1 (CS), 58.8 mm SL.

Non-types. ZMA 102.400, 8, 31.3–66.0 mm SL, Meer van Manindjau, M. Weber, 1888.

Diagnosis. Rasbora maninjau is distinguished from congeners by the combination of the following characters: the black midlateral stripe extending from the midhumeral region with a relatively uniform width and lacking the subdorsal blotch; the prominent acutely triangular basicaudal blotch; and the oval supra-anal pigmentation. Rasbora maninjau is further distinguished from the three other species of the Sumatrana group in northern Sumatra ( Rasbora arundinata , R. haru , and R. bindumatoga ) in having: 26–27 + 3–4 lateral-line scales (vs. 24–25 + 4; Table 2); 13 gill rakers on the first gill arch (vs. 10–12); 34 vertebrae (vs. 32–33); a relatively narrow body with a mean of 24.1% SL (vs. 26.3–29.7%); and a relatively narrow caudal peduncle with a mean of 11.9% SL (vs. 13.9– 14.9%). Rasbora maninjau 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 Figure 2 C. Morphometric and meristic data given in Table 2. Dorsohypural distance equal to distance from dorsal-fin origin to nostril. Limit between head and trunk distinct in lateral view. Cephalic tubercles present on males. No female specimen examined. Tubercles relatively small, distributed over most of head surface, extending onto nape region as far as second predorsal scale and to several scales on anteroventral region of body. Lateral line complete (all scales perforated; 26–27 + 3–4). Dorsal-fin origin situated 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 barely reaching vertical through anal opening. Anal-fin origin located below 18th lateral-line scale.

Rasbora maninjau Rasbora bindumatoga n = 7 n = 22

Range Mean ± SD Range Mean ± SD Standard length (mm) 57.3–82.7 68.4 ± 9.0 23.3–72.0 48.6 ± 12.5 Percentage of standard length

Total length 130–136.3 134.5 ± 2.1 137.1–141.9 139.0 ±1.3 Head length 24.3–26.0 24.9 ± 0.7 24.1–31.3 27.7 ± 1.5 Predorsal length 52.7–56.2 54.2 ± 1.1 51.6–57.0 54.3 ± 1.3 Preanal length 68.9–73.7 71.0 ± 1.5 68.7–74.1 71.9 ± 1.5 Prepelvic length 47.1–52.7 49.6 ± 2.2 47.7–72.5 51.7 ± 4.9 Dorsal depth 21.4–24.1 23.0 ± 1.0 23.1–28.6 26.0 ± 1.7 Body depth 21.3–26.5 24.1 ± 1.6 25.0–29.9 27.3 ± 1.3 Caudal-peduncle depth 11.0–12.6 11.9 ± 0.5 12.0–15.1 14.0 ± 0.7 Caudal-peduncle length 16.5–19.4 18.3 ± 1.1 14.5–17.9 16.3 ± 0.9 Dorsal-fin base length 11.1–12.6 11.9 ± 0.5 11.4–15.0 12.9 ± 0.9 Anal-fin base length 11.0–12.6 12.0 ± 0.6 11.0–13.1 12.3 ± 0.6 Pelvic-fin length 17.1–20.3 18.7 ± 1.5 17.6–22.0 19.9 ± 1.1 Pectoral-fin length 21.0–22.5 21.7 ± 0.5 22.2–25.7 24.3 ± 1.0 Upper caudal lobe length 30.2–34.0 32.5 ± 1.5 32.8–40.1 36.7 ± 2.0 Median caudal length 14.0–16.3 15.5 ± 0.9 16.1–21.0 18.3 ± 1.2 Lower caudal lobe length 30.7–36.8 34.1 ± 2.5 35.4–42.8 37.4 ± 1.8 Dorsohypural distance 48.0–51.3 50.0 ± 1.3 48.1–54.7 50.8 ± 1.7 Percentage of head length

Eye diameter 27.1–32.2 29.2 ± 2.0 23.9–33.1 30.5 ± 2.0 Snout length 26.7–30.5 29.2 ± 2.0 26.8–31.3 29.0 ± 1.4 Head width 47.1–52.1 50.5 ± 1.8 49.0–58.2 54.1 ± 2.6 Head depth 63.4–69.2 65.2 ± 1.9 63.3–74.1 68.1 ± 3.0 Interorbital width 25.3–28.7 26.7 ± 1.2 25.7–32.6 29.7 ± 2.1

Range Mode (n) Range Mode (n) Meristics

Gill rakers on 1st gill arch 13 13 (1) 11–12 11 (4) Pharyngeal teeth formula 5,4,1 5,4,1 (1) 5,4,2 5,4,2 (4) Dorsal-fin rays i, 7½ i, 7½ (7) i, 7½ i, 7½ (10) Pectoral-fin rays i, 11–13 i, 12 (7) i, 11–13 i, 12 (10) Pelvic-fin rays i, 8 i, 8 (7) i, 8 i, 8 (10) Anal-fin rays ii, 5½ ii, 5½ (7) ii, 5½ ii, 5½ (10) Dorsal procurrent rays of caudal fin 7 7 (7) 7–8 8 (10) Dorsal principal rays of caudal fin 9 9 (7) 9 9 (10) Ventral procurrent rays of caudal fin 8 8 (7) 8 8 (10)

......continued on the next page Rasbora maninjau Rasbora bindumatoga n = 7 n = 22

Coloration in alcohol. General body coloration in alcohol in alcohol preservation shown in Fig. 2 C. Schematic lateral body pigmentation shown in Fig. 9 B. Lachrymal region superficially pigmented with peripheral portion more densely pigmented. Dusky gular pigmentation decreasing in intensity posteriorly until reaching to anterior portion of branchiostegal flaps. Peripheral reticulation very prominent and covering at maximum 5 1/2 longitudinal scale rows along dorsolateral, midlateral, and ventrolateral portions of body. Basal reticulation very prominent and covering at maximum 5 longitudinal scale rows, with network of continuous parenthesis-shaped bars. Peripheral and basal reticulation maximally overlapping on first to fifth longitudinal scale rows and also on dorsal scale row.

Black midlateral stripe prominent, more intense posteriorly, and of uniformly approximately one-third scale wide along posterior of flank until reaching vertical through mid-point of dorsal-fin base. Stripe slightly tapering anteriorly below dorsal fin with ventral margin becoming diffuse with less concentrated melanophores until completely replaced by swath of stellate melanophores reaching pectoral girdle along almost all of anterior half of flank. Dorsal edge of stripe bordered by axial streak from hypural notch to midhumeral region. Deeply-embedded diamond-shaped black basicaudal blotch confluent with black midlateral stripe anteromedially and terminating at anterior sheath scales of caudal fin. Blotch consisting of two elements: basicaudal triangular patch originating posterior to hypural notch and flaring posteriorly to maximum one-fourth of caudal-peduncle depth; and darker basicaudal spot terminating anterior to sheath scale of caudal fin. Axial streak posteriorly juxtaposed dorsal margin of black midlateral stripe, but separating from stripe in area above 11th lateral-line scale. Streak decreasing in intensity anteriorly until disappearing on mid-humeral region. Dusky dorsolateral stripe somewhat distinct, most prominent and with maximum depth of almost one scale wide along anterior portion of trunk; slightly tapering posteriorly and bordered ventrally by longitudinal light area. Longitudinal light area somewhat obscure, masked by dusky pigmentation on each anterior portion of scale, extending longitudinally between dusky and black lateral stripes, most prominent along mid-point of body to caudal peduncle. Supra-anal pigmentation originating posterior to anal-fin origin and terminating at base of 2nd branched anal-fin ray, appearing as distinct ellipsoidal blotch. Subpeduncular pigmentation distinct, most intense along mid-point of subpeduncular region. Longest ray of each caudal-fin lobe covered by dense melanophores along its length. 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, midlateral and ventral surfaces whitish to silvery due to presence of reflective guanine ( Fig. 5 A–C). Dorsum of head largely dusky, with several faint scattered yellowish patches and streaks on snout, lateral-line canals, meningeal layer, and occipital region ( Fig. 4 B–C). Black pigmentation on lateral body somewhat obscure, most visible posteriorly, with metallic greenish to bluish sheen. Reflective midlateral stripe metallic orange-reddish, extending from humeral region to caudal peduncle with relatively equivalent width, juxtaposed ventrally by obscure black midlateral stripe, and terminating at distinct black basicaudal blotch. Black reticulation pattern relatively distinct. All fins hyaline. Habitat and distribution. Specimens of Rasbora maninjau were collected in Lake Maninjau , a crater lake in central western Sumatra draining to the Indian Ocean ( Fig. 8 ). This species is a favorite among local people for food and is known as ‘ikan badar’ in Minang, the native language of the area.

Etymology. The specific name, maninjau , a noun in apposition, refers to the name of the type locality, Lake Maninjau .

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 5. Photographs of living specimen of Rasbora maninjau, MZB 17890 (holotype).

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.

FIGURE 9. Schematic drawing of left lateral view of three primary diagnostic lateral pigmentation characteristics of members of the Lateristriata subgroup: (A) R. lateristriata; (B) Rasbora maninjau; (C) R. vulgaris; (D) R. paviana.