Betta pardalotos, Hui, 2009

Hui, Tan Heok, 2009, Betta Pardalotos, A New Species Of Fighting Fish (Teleostei: Osphronemidae) From Sumatra, Indonesia, Raffles Bulletin of Zoology 57 (2), pp. 501-504 : 501-504

Betta pardalotos , new species

( Figs. 1–5 )

Material examined. – Holotype – MZB 10999 (53.3 mm SL), Indonesia, Sumatra: South Sumatra Province; Musi drainage; Palembang, Laut Kenten , Sungai Gelam ; T. Sim , 11 Oct.2006.

Paratypes – CMK, 2 ex., MZB 11000, 2 ex., ZRC 51837, 5 ex. (48.6–61.2 mm SL), same locality data as holotype . — ZRC 51838, 2 ex., (54.0– 72.4 mm SL), same locality as holotype, 5 June 2006 . — ZRC 51839, 1 ex. (55.4 mm SL), same locality as holotype, M. Kottelat & H. H. Ng, 14 May 2008 .

Diagnosis. – Betta pardalotos can be distinguished from other members of the B. waseri group in having the following combination of characters: two white rounded patches on a black throat ( Figs. 2 , 3 , 5 ); opercle with three arched rows of black dots following opercle edge; black transverse bars on the dorsal and caudal fin interradial membranes; absence of a dark distal border on anal fin; operculum without lower distal margin black. It is further differentiated from the closely allied B. chloropharynx

Standard length (mm) 53.3 51.7 72.4 Anal fin rays (total) 29 (II,27) 27 30 29 Dorsal fin rays (total) 10 (I,9) 9 10 10 Pelvic fin rays 1, 5 1, 5 Pectoral fin rays 12 12 Subdorsal scales 7 7 7 ½ 7 Transverse scales 10 10 Lateral scales 33 33 34 34 Lateral scale below dorsal fin origin 16 15 17 16 Lateral scale above anal fin origin 6 6 7 6 Predorsal scales 24 23 26 24 Postdorsal scales 13 12 13 12

% standard length Min. Max. mean SD (±) Total length 167.1 135.7 167.1 144.1 9.77 Body length 67.0 65.9 69.8 68.2 1.32 Predorsal length 67.2 65.2 67.2 66.3 0.88 Postdorsal length 21.7 21.4 24.4 22.9 1.23 Caudal peduncle depth 21.7 18.4 21.7 20.1 0.94 Preanal length 46.3 41.5 57.8 45.3 5.44 Head length 35.6 32.5 35.8 34.1 1.13 Body depth 29.5 24.7 29.5 27.0 1.41 Pelvic fin length 34.0 28.7 34.3 31.7 2.10 Anal fin base length 55.9 53.7 58.9 56.7 1.77 Dorsal fin base length 14.4 12.9 14.8 13.8 0.68 % head length Orbit diameter 25.5 23.2 28.8 26.6 1.76 Postorbital length 47.1 47.1 54.3 50.6 2.89 Interorbital width 39.2 37.3 41.8 39.1 1.44 Snout length 28.3 22.8 29.2 25.8 2.05

( Fig. 6 ) in having the following characters: heavily spotted opercle (vs. no spots); even sloping or convexity at area posterior to upper jaw to supra-orbital area (vs. slight concavity); body dusky with irregular blotches (vs. uniform body pattern); anal-fin origin at lateral scale 6–7 (vs. 8); deeper caudal peduncle (18.4–21.7% SL, vs. 16.7–18.8); longer head (32.5–35.8% SL, vs. 29.9–33.7); more lateral scales (modally 34, vs. 33).

Description. – General body form as in Figs. 1 , 4 ; meristics and morphometrics listed in Table 1. Body relatively long and stout (body depth at dorsal fin origin 24.7–29.5% SL); head stout with pointed snout and evenly sloping or slight convexity at supra-orbital area (head length 32.5–35.8% SL); dorsal fin pointed, situated nearer to caudal fin (predorsal length 65.2–67.2% SL), dorsal fin base short (dorsal fin base length 12.9–14.8% SL), covering 7–7 ½ subdorsal scales; caudal fin rounded with median rays elongate; anal fin with posterior rays elongate, anal fin base more than half of SL (anal fin base length 53.7–58.9% SL); pelvic fin falcate with first ray filamentous, relatively long (pelvic fin length 28.7–34.3% SL), reaching up to 12th anal fin ray; pectoral fin rounded. Vertebral count: 11–12 + 19–21 (total 31–32, mode 32, n=10).

Live colouration. – See Figs. 1–3 for live colouration. Head and body dorsum dark brown. Eye with unique colouration zones of the B. waseri group (as defined by Tan, 1998). Lower jaw with lower and upper lips black, throat with two white semi-circles (curved surface facing downwards; see Figs. 2 , 3 , 5 ), bordered below with black chin bar. Lower half of opercle creamy white with light greenish-gold iridescence, lower half of opercle distinctly covered with three rows of fairly regularly spaced small black spots, arranged according to curvature of opercle edge. Body yellowish-brown, with indistinct central dark brown stripe, with faint dark patches just above anal fin sheath scales. Dorsal fin brownish with up to 13 transverse bars on interradial membrane. Caudal fin brownish with up to 16 transverse bars on interradial membrane. Anal fin brownish, without distal dark border but with very thin white margin. Pelvic fins yellowish-brown with whitish interradial membrane, distal part of pelvic fin filamentous ray iridescent whitish-green. Pectoral fin hyaline with a black sub-basal bar.

Preserved coloration. – Preserved coloration illustrated in Figs. 4–5 . Colouration as above, except no iridescence present and opercle pattern indistinct on some specimens.

Distribution. – Betta pardalotos is currently known only from the Musi basin in South Sumatra province in Sumatra, Indonesia ( Fig. 7 ).

Field notes. – The type locality is a tributary of the lower part of Musi River, as such there are euryhaline elements present, as seen in the presence of Nypa palms, Hemibagrus hoevenii (a bagrid catfish known only from lower reaches of rivers), Zenarchopterus ectuntio and various gobiid species. However, Betta pardalotos was obtained from smaller feeder streams, which were freshwater. Syntopic osphronemids present include: Belontia hasseltii , Betta edithae , Luciocephalus pulcher and Trichopodus trichopterus .

Etymology. – From the Greek pardalis , of the feline leopard ( Panthera pardalis , an inhabitant of the tropical rainforests in Southeast Asia), alluding to the spotted pattern on the opercle.

Comparative material. – See Kottelat & Ng (1994), Ng & Kottelat (1994), Tan (1998) and Tan & Ng (2005a and 2005b) for a list of comparative material.

Additional material. – Betta chloropharynx – ZRC 47248, 1 ex. (69.3 mm SL), Indonesia, Sumatra: Banka; D. Yong, Jul.2001 . — ZRC 51825, 6 ex., (43.8–73.1 mm SL), Indonesia, Sumatra: Banka; N. Takahashi, 30 Jul.2002 .

Figures

Fig. 1. Betta pardalotos, ZRC 51838, paratype, 72.4 mm SL.

Fig. 2. Betta pardalotos, ZRC 51838, paratype, 72.4 mm SL, close-up of head.

Fig. 3. Betta pardalotos, ZRC 51838, paratype, 72.4 mm SL, front view of head showing lower jaw, throat and opercle pattern.

Fig. 4. Betta pardalotos, MZB 10999, holotype, 53.3 mm SL.

Fig. 5. Betta pardalotos, ZRC 51837, paratype, 61.2 mm SL, close-up of head pattern, lateral and ventral views.

Fig. 6. Betta chloropharynx, ZRC 35166, 56.6 mm SL, holotype; Sumatra: Banka Island."

Fig. 7. Map of Sumatra showing location of Betta chloropharynx (square) and B. pardalotos (circle).