Betta anabatoides Bleeker, 1851

Tan, Heok Hui, 2009, Redescription of Betta anabatoides Bleeker, and a new species of Betta from West Kalimantan, Borneo (Teleostei: Osphronemidae), Zootaxa 2165, pp. 59-68 : 60-64

Betta anabatoides Bleeker, 1851

( Figs. 1–2 )

Betta anabatoides Bleeker, 1851: 269 — Weber & de Beaufort, 1922: 357 (part); Vierke, 1979: 390; Linke, 1991: 26; Kottelat et al., 1993: 222 (part), pl. 75.

Betta picta (non Valenciennes) — Bleeker, 1879: 26 (part).

Material examined. Neotype. ZRC 40971, 47.2 mm SL; South Kalimantan: Banjarmasin, stream at km 55 on Rantau–Martapura road; H. H. Ng & O. K. S. Chia, 6 June 1996.

Other material. South Kalimantan — ZRC 43710, 1 ex., 55.3 mm SL; same locality data as neotype. — CMK 16740, 1 ex., 37.4 mm SL; Barito River basin, area of Tamiyang Layang (02°1'S 115°7'E); T. Idei, 7 Sep 2000. — ZRC 51536, 9 ex., 33.0– 82.2 mm SL; Tamiyang Layang area; T. Idei, 2004. — ZRC 51533, 1 ex., 48.9 mm SL; Relaihari, Gunung Raya, South of Banjarmasin; T. Idei, 2004. — ZRC 51535, 1 ex., 52.4 mm SL; Pelaihari, Gunung Raya (03º40’07”S 114º40’35”E); T. Idei, 2004. — ZRC 51534, 1 ex., 53.4 mm SL; Satai, East Point; T. Idei, 2004. Central Kalimantan — CMK 16707, 1 ex., 33.3 mm SL; Sampit river basin, 45 km west of Sampit (02°30'S 112°38'E); T. Idei, 20 Jul 2000. — CMK 16696, 1 ex., 55.9 mm SL; Sampit river basin, 15 km north of Parenggean (01°56'S 112°43'E); T. Idei, 16 Jun 2000. — ZRC 51537, 8 ex., 34.8–60.0 mm SL; Sampit river basin, southeast of Kuala Kuayang; T. Idei, 2004. — ZRC 51538, 10 ex., 47.0– 70.2 mm SL; Plantalang Hulu (02º01’40”S 112º59’48”E); T. Idei, 2004. — ZRC 22842–43, 2 ex., 46.7–55.9 mm SL, CAS 96958, 4 ex., 35.7–59.4 mm SL; Mentaya basin, Sungai Ramban, 22 km west of Sampit on road to Pembuanghulu; T. R. Roberts, 11 Jun 1992. — ZRC 51539, 45 ex., 40.4–65.6 mm SL; Katingan river basin, east of Kasongan (01°54’S 113°25’E); T. Idei, 2004. — CMK 16764, 2 ex., 45.5–48.0 mm SL; Barito river basin: 15 km east of Buntok; T. Idei, 13 Sep 2000.

Diagnosis. Betta anabatoides is unique in having the following combination of characters: a thick-set body (body depth 30.5–33.7 % SL) with the anterior part of the body reminiscent of the taxon Anabas ; head devoid of pattern except for a preorbital stripe that runs from the black lower lip to the eye, and continuous with a postorbital stripe to the posterior edge of the opercle; in living specimens, the opercle with faint gold iridescent scales; and some median caudal rays projecting beyond the fin margin (adapted from Kottelat et al., 1993).

Description. General appearance as illustrated in Figs. 1–2 . Meristic and morphometric data listed in Table 1. Head broadly pointed (anterior body reminiscent of Anabas : Fig. 1 ), relatively long (HL 32.8–34.9 % SL); body thick-set (body depth 30.5–33.7 % SL); pectoral fin rounded; pelvic fin filamentous; dorsal fin situated far back (predorsal length 66.8–69.7 % SL); dorsal and anal fins pointed, with elongated posterior rays; caudal peduncle deep (caudal peduncle depth 19.8–22.1 % SL); caudal fin lanceolate, some median rays projecting beyond fin margin. Large male specimens with longer unpaired fins and darker body coloration.

Coloration in life. See Fig. 2 , and refer to Vierke (1979: 389), Linke (1991: 26) and Kottelat et al. (1993: pl. 75) for colour illustrations. Dorsum of body brown, venter lighter brown. Dorsum of head brown with darker brown blotches behind eye; opercle with faint gold iridescence. Distinct pre- and postorbital black stripes on head; lower lip black; chin-bar absent. No iridescence on body. Sides of body plain brown, sometimes with 5–7 faint, irregularly-spaced vertical brown bars. Fins brownish, dorsal fin with 5–6 darkbrown transverse bars;caudal fin without pattern. Pectoral fin hyaline. Pelvic fin with a bright whitish distal tip.

Coloration in preservative. See Fig. 1 . Dorsum of body dark brown, venter lighter brown to whitish. Dorsum of head dark brown, opercular area whitish. Distinct pre- and postorbital black stripes on head; chinbar absent. Body with 5–7 irregularly spaced vertical dark-brown bars. Fins brownish; dorsal fin with 5–6 transverse black bars, caudal fin without pattern. Pectoral fin hyaline. Pelvic fin light brown, its filamentous second ray hyaline.

Distribution. Betta anabatoides is known from the lower Barito basin in South Kalimantan and the Kotawaringin, Katingan, Sampit, Mentaya and Kahayan basins in Central Kalimantan ( Fig. 3 ; pers. obs.), in Indonesian Borneo.

Field notes. The stream in which the neotype material of B. anabatoides was obtained in Banjarmasin was murky, up to 1.2 m deep and pH 7.5. The water was sluggish and drained from cultivated area upstream. Syntopic fishes included: Boraras brigittae , Rasbora agyrotaenia , R. einthovenii , R. gracilis (Cyprinidae) , Lepidocephalichthys hasseltii (Cobitidae) , Hemirhamphodon pogonognathus (Hemiramphidae) , Calamiana paludosus (Gobiidae) , Betta edithae , Trichopodus trichopterus , Trichopsis vittata (Osphronemidae) .

In Central Kalimantan, the streams in which B. anabatoides can be found lie within a mix of heath and peat swamp forest habitats. These habitats are usually typified by clear, highly tannified and very acidic waters ( pH as low as 3.5). The substrate is a mix of silicate sand and peat.

Remarks. Betta anabatoides can be differentiated from its closest relative, B. midas , by the following characters: a more thick-set body (body depth 30.5–33.7 % SL, vs. 24.3–29.0); a deeper caudal peduncle (19.8–22.1 % SL, vs. 16.8–19.0); absence (vs. presence) of caudal transverse bars; faint (vs. distinct) iridescent gold opercle scales; absence (vs. presence) of gold body scales; pointed (vs. blunt) lateral head profile; a slightly greater predorsal length (66.8–69.7 % SL, vs. 65.5–67.4); and a slightly greater anal-fin base length (55.2–61.1 % SL, vs. 52.4–57.9).

Betta anabatoides can be differentiated from B. akarensis and B. ibanorum by the following suite of characters: absence (vs. presence) of chin-bar; caudal fin without pattern (vs. caudal transverse bars present); a greater body depth (30.5–33.7 % SL, vs. 23.3–30.9); a greater anal-fin base length (55.2–61.1 % SL, vs. 49.6–56.8); a shorter caudal fin length (total length 135.5–142.3 % SL, vs. 134.4–165.6); a greater number of anal fin rays than B. ibanorum (29–31, vs. 27–29) and a smaller preanal length than B. ibanorum (44.9–46.7 % SL, vs. 45.8–49.4) (data on B. akarensis and B. ibanorum from Tan & Ng, 2004).

Figures

FIGURE 1. Betta anabatoides, ZRC 40971, 47.2 mm SL, neotype, Banjarmasin (right side, laterally inverted).

FIGURE 2. Betta anabatoides, not preserved, ca. 35 mm SL, Central Kalimantan.

FIGURE 3. Map showing known distribution of B. anabatoides (circle) and B. midas (square) in Borneo.