Schistura pantherina, Page, Plongsesthee and Randall

Page, Lawrence M., Plongsesthee, Rungthip, Beamish, F. William H., Kangrang, Punnatut, Randall, Zachary S., Singer, Randal A. & Martin, Zachary P., 2012, Schistura (Teleostei: Nemacheilidae) in the Mae Khlong basin in southwestern Thailand with description of a new species, Zootaxa 3586, pp. 319-328 : 320-323

Schistura pantherina, Page, Plongsesthee and Randall

( Figs. 1–3)

Holotype. NIFI 4675 , 60.2 mm SL; Thailand, Kanchanaburi Prov., Thong Pha Phum, Mae Khlong basin, Mae Nam Kwai Noi system, Kroeng Krawia , on Hwy 323 at km 32, near Prang Phe , 14º58'17"N, 98º38'24"E, 24 Apr. 2011, Rungthip Plongsesthee, F. William H. Beamish, Larry M. Page and Randal A. Singer.

Paratypes. UF 184183, 26.7 –42.0 mm SL, Thailand, Kanchanaburi Prov., Thong Pha Phum, Mae Khlong basin, Mae Nam Kwai Noi system, Kroeng Krawia , on Hwy 323, 14º55'N, 98º40E, 22 Feb. 2012, Rungthip Plongsesthee and Raphael Lagarde .

Diagnosis. Member of genus Schistura as defined by Kottelat (1990). Distinguished from all other species of Schistura by unique color pattern consisting of 11–16 black spots along mid-side, black spots on top of head and predorsal area continuing as a row of spots to the caudal base, and a short vertical black bar at the caudal-fin base. It is further distinguished from similar species by the following combination of characters: no black suborbital bar; lateral line extending almost to caudal fin; dorsal-fin rays iv, 8½; anal-fin rays iii, 5½; pectoral-fin rays i, 10; pelvic-fin rays i, 7; and caudal fin with 9 branched rays in upper half, 8 branched rays in lower half.

Description. Body shape and color are shown in Figures 1–3. Morphometric data are in Table 1. Largest specimen is the holotype, 60.2 mm SL, 74.7 mm TL.

Body long, slender, slightly deeper than wide. Body depth fairly uniform throughout, slightly deeper at dorsalfin origin than at caudal peduncle. Profile of snout and head pointed, more so in juveniles. Snout moderately pointed in dorsal view. Head depressed; eye oval, longer than high, near dorsal profile, directed dorsolaterally.

Dorsal-fin origin above pelvic-fin origin. Pectoral fin reaches over half distance from pectoral-fin origin to pelvicfin origin. Pelvic fin reaches anus. Axillary pelvic lobe present. Anal fin not reaching caudal fin. Margins of dorsal and anal fins convex. Caudal fin emarginate. Small adipose crest on dorsal margin, none or very small crest on ventral margin, of caudal peduncle; dorsal crest more pronounced on juvenile. No suborbital flap; no apparent sexual dimorphism.

Body scaled, except scales absent on venter anterior to pelvic fin. Scales embedded on anterior side of body, becoming less so near vertical from origin of dorsal fin. Scales embedded on venter between pelvic fins and anus. Scales on anterior part of body deeply embedded; lateral line complete nearly to caudal fin with about 115 scales and 90 pores on holotype; 82 scales around narrowest part of caudal peduncle on holotype. Dorsal-fin rays iv, 8½; anal-fin rays iii, 5½; pectoral-fin rays i, 10; pelvic-fin rays i, 7; caudal fin with 9 branched rays in upper half, 8 branched rays in lower half.

Cephalic lateralis system (pores countable on two specimens) with 4 + 8 supraorbital pores, 8 infraorbital pores, 8–9 preoperculomandibular, and 3 supratemporal pores. Lips moderately thick, pleated, covered with unculi; upper lip with very small median incision; lower lip with median notch in small individuals, with median incision in larger individuals ( Fig. 3). Processus dentiformis present. Inner rostral barbel almost reaching to corner of mouth; outer rostral barbel reaching horizontally to anterior edge of orbit. Maxillary barbel reaching horizontally to or slightly past posterior edge of orbit. Barbels covered with unculi. Anterior nostril at base of short flap.

Coloration. In life ( Fig. 2), Schistura pantherina has a row of 11–16 greenish-black spots or blotches along the side. In larger individuals, the first few and the last few are confluent, and all spots are overlain by a dusky silver-gray stripe. In smaller individuals, the stripe is darker and the spots are less obvious. The midlateral row of spots is followed by a medial to slightly submedial black basicaudal bar that spans approximately 6–11 rays. Greenish-black spots and vermiculations on top of the head and predorsal area continue as a row of spots to the caudal base. The predorsal area immediately in front of the dorsal fin and the first dorsal ray are tinged with red.

The upper half of the head is yellow-green, the lower half is yellow-white. There is a diffuse preorbital bar but no black suborbital bar. The lower side of the body and venter are yellow-white and lack dark pigment. The dorsal fin has a sub-basal row of black spots, one on each ray, followed distally by a clear area that is deeper at the front of the fin than at the rear, then by two more rows of smaller black spots along the rays. The distal one-fourth of the fin is clear. The caudal fin has a red tinge along the upper- and lower-most rays and two faint bars formed by rows of small brown to black spots. The pectoral and pelvic fins are suffused with red and yellow; the anal fin is clear.

The smallest individuals examined (32.1–38.2 mm SL) have the pattern of the largest individual except the midlateral black stripe is more pronounced, the dorsal and lateral blotches are smaller and lighter in color, and the fins lack the red and yellow pigments.

In preserved specimens, the greenish aspect of the black spots and blotches, and the red and yellow pigments on the fins are absent. The dark spots, especially those on the dorsum are more brown than black.

Etymology. The name, pantherina, Latin adjective meaning 'like a panther,' is in reference to the spotted pattern on the dorsum and sides of some members of the felid genus Panthera .

Distribution and ecological notes. Schistura pantherina is known only from the Kroeng Krawia, Kwai Noi, Mae Khlong basin, in the Thong Pha Phum District of Kanchanaburi Province, Thailand ( Fig. 4). Specimens were captured in flowing water in shallow rubble and gravel riffles ( Fig. 5). This is the second species of Schistura that appears to be endemic to this basin, the other being S. tenebrosa ( Kangrang et al. 2012) .