Laogarra heokheei, Kottelat, 2025

Kottelat, Maurice, 2025, Laogarra heokheei, a new genus and species of ' garra' from north-eastern Laos (Teleostei: Cyprinidae), Zootaxa 5666 (3), pp. 389-407 : 392-395

Laogarra heokheei sp. nov.

( Figs. 5–7 )

Holotype. MHNG 2797.028 , 62.7 mm SL; Laos: Xiangkhouang Province: Nam Mo watershed; Nam Ngiem at Ban Nam Ngiem [Ban Tamxôy]; 775 masl; 19°00'50"N 103°58'24"E; M. Kottelat & T. Phommavong, 9 May 2023.

Paratypes. CMK 28985 , 2 , 23.0– 65.5 mm SL; same data as holotype .

Diagnosis. Laogarra heokheei is distinguished from all other garras by the combination of characters mentioned in the above diagnosis of the genus.

Description. See Table 1 for morphometric data of holotype and largest paratype. Body moderately elongate, compressed. Dorsal body profile convex from snout to dorsal fin, straight behind dorsal-fin base; ventral profile slightly convex (less arched than dorsal profile). No hump at nape. Head longer than deep, slightly depressed, dorsal profile convex, more so than ventral profile, snout rounded. Interorbital space slightly convex. Caudal peduncle 1.5–1.7 times as long as deep.

See details of mouth and disc under generic diagnosis. Maxillary barbel short, less than half eye diameter, inserted at anterior extremity of rostral cap; mandibular barbel very short, at lateral extremity of rostral cap ( Fig. 2 ). A few small tubercles on tip of snout and rostral cap.

Dorsal fin with 4 simple and 8½ branched rays; first branched ray longest; distal edge concave; origin in front of pelvic-fin base; dorso-hypural distance almost reaching tip of snout when reported forward from dorsal-fin origin. Pectoral fin rounded, with 1 unbranched and 13* or 14 branched rays, reaching posteriorly halfway to pelvic-fin base. Pelvic fin rounded, posterior margin straight, with 1 unbranched and 8 branched rays; reaching slightly beyond anus; origin at vertical through base of branched dorsal-fin rays 2 to 3, closer to anal-fin origin than to pectoral-fin origin; axillary scale reaching beyond base of last ray of fin. Anal fin with 3 unbranched and 5½ branched rays; first branched ray longest; distance between tips of first and last branched rays (stretched out) smaller than depth of caudal peduncle. Caudal fin with 9+8* or 8+7 branched rays, forked, lobes pointed, subequal; length of median rays 1.5–1.7 times in length of upper lobe.

Lateral line complete, with 38+2* or 40+2 pored scales. ½5 scale rows between dorsal-fin origin and lateral line row; 6½ scale rows between lateral line row and ventral midline (counted at level of 2 scales in front of pelvic-fin base); 3 scale rows between lateral line and pelvic-fin origin; 4* or 4½ scale rows between lateral line and anal-fin origin; ½3/1/2½ scale rows on caudal peduncle (at narrowest point, elsewhere ½3/1/3½); 14 predorsal scales. Three scales between anus and anal-fin origin. Base of caudal fin with only 3 prominent scales, much larger than scales immediately in front ( Fig. 4 ).

Coloration. After 1 month in 10% formalin ( Figs. 5 , 6a ). Dorsal half of head and body dark brown, ventral half pale (holotype has darker body and darker pigments extending lower on flank). A darker mid-dorsal stripe. On dark part of body, each scale with a broad margin of densely set pigments, including large scales at caudal-fin base. Some scales entirely covered by dense pigment, appearing almost black.

Dorsal fin membranes hyaline, with black pigments on proximal part of rays; then along edges of rays and between segments, with pale grey patches between branches. Caudal fin hyaline, with pigments along rays and between segments; upper and lower principal unbranched rays and adjacent 1 or 2 branched rays more densely pigmented and appearing as a dark grey edge. Anal fin hyaline. Pelvic fin hyaline, with small melanophores on dorsal face of all rays, denser on rays 1 and 2. Pectoral fin hyaline, with small melanophores on dorsal face of all rays, denser on rays 1–4.

Juvenile ( Fig. 7 ): body yellowish grey. Scales with broad band of pigmentation along posterior edge; on lateral-line scales, band of pigments appearing as divided into a pair of spots, above and below line.

In life and immediately after fixation ( Fig. 6b ): As for preserved specimens except as follows: head and body greenish brown; scales with black margin. Belly whitish. All fins orange.

Distribution. Laogarra heokheei is presently known only from the type locality in the Nam Ngiem, in Nam Mo watershed in Laos. The Nam Mo joins the Nam Neun, which becomes the Nam Ka on the Lao-Vietnamese border, and Song Ca in Vietnam, which becomes Song Lam, going on to flow eastwards to the Gulf of Tonkin in Vinh.

Habitat. At the place of sampling, the Nam Ngiem is a small stream with a high-gradient flow over stones and boulders ( Fig. 8 ). The exact microhabitat was not observed in the field. Other highly rheophilic fish species collected at this locality include: Ageneiogarra cyclostomata , Scaphiodonichthys sp. , Vanmanenia sp. , Schistura pervagata , and two species of Oreoglanis .

Etymology. The species is named in honour of Ng Heok Hee, in appreciation for his work on Asian catfishes and our long collaboration in the study of species from Laos. A noun in the genitive case.

Figures

FIGURE 2. Laogarra heokheei; mouth and disc; a, MHNG 2797.028, holotype, 62.7 mm SL (arrows: upper lip); b, CMK 28985, 65.5 mm SL (arrow: postpulvinal groove); c, CMK 28985, 23.0 mm SL.

FIGURE 4. Laogarra heokheei, MHNG 2797.028, holotype, 62.7 mm SL; caudal fin.

FIGURE 5. Laogarra heokheei, MHNG 2797.028, holotype, 62.7 mm SL; Laos: Xiangkhouang: Nam Neun drainage: Nam Mo watershed.

FIGURE 6. Laogarra heokheei, CMK 28985, paratype, 65.5 mm SL; Laos: Xiangkhouang: Nam Neun drainage: Nam Mo watershed. a, preserved; b, immediately after capture.

FIGURE 7. Laogarra heokheei, CMK 28985, paratype, 23.0 mm SL; Laos: Xiangkhouang: Nam Neun drainage: Nam Mo watershed; right side, reversed.

FIGURE 8. Laos: Xiangkhouang Province: Nam Ngiem drainage, Nam Mo watershed; 9 May 2023. Type locality of Laogarra heokheei.

Tables

TABLE 1. Laogarra heokheei, morphometric data of holotype and adult paratype.

	Holotype	Paratype
	MHNG 2797.028	CMK 28985
Standard length (mm)	62.7	65.5
Total length (mm)	81.1	83.4
In percent of standard length
Total length	129.4	127.4
Head length	27.6	25.2
Predorsal length	52.0	50.6
Prepelvic length	52.9	51.3
Preanal length	73.8	72.0
Head depth	14.5	15.2
Body depth at dorsal-fin origin	22.6	21.4
Depth of caudal peduncle	13.6	12.8
Length of caudal peduncle	20.6	20.9
Head width	18.7	16.6
Mouth width	10.1	11.2
Eye diameter	5.3	5.7
Snout length	13.7	11.7
Interorbital distance	12.9	11.4
Length of dorsal fin	20.5	20.1
Length of dorsal-fin base	12.6	13.7
Length of upper caudal-fin lobe	27.1	25.7
Length of median caudal-fin rays	16.2	17.0
Length of lower caudal-fin lobe	27.5	26.2
Length of anal fin	19.8	19.2
Length of pelvic fin	18.3	17.7
Length of pectoral fin	20.8	20.7
In percent of head length
Head width	68	66
Mouth width	37	45
Eye diameter	19	23
Snout length	50	47
Interorbital distance	47	45