Ghatsa

Randall, Zachary S. & Page, Lawrence M., 2015, On the paraphyly of Homaloptera (Teleostei: Balitoridae) and description of a new genus of hillstream loaches from the Western Ghats of India, Zootaxa 3926 (1), pp. 57-86 : 81-83

Redescription of Ghatsa montana ( Herre 1945)

( Figures 4 F, 5F, 16)

Homaloptera montana Herre 1945:400 (no figure in original description); Journal of the Washington Academy of Sciences 35(12).

Type locality: brook on the Puthutotam Estate in Anamallai Hills at 3,600 feet altitude, Valparai Post Office, Madras Presidency, South India. Holotype. CAS-SU 39871, Böhlke 1953:40.

Description. Dorsal, lateral, and ventral views are shown in Figure 16 . Measurements and meristic counts are given for the only specimen available to us, the holotype (CAS-SU 39871). The holotype is 46.4 mm SL, 54.8 mm TL. Body (depth: 10.1% SL, width: 13.5% SL) arched predorsally, tapers posterior of anal-fin origin to caudal base, flattened ventrally. Head (length: 21.7% SL, width: 76.2% HL, depth: 44.5% HL) triangular when viewed dorsally; tubercles absent. Snout length 47.5% HL. Orbit (length: 22.8% HL) small, ovoid, positioned dorsolaterally, shorter than interorbital width (31.7% HL).

Mouth ( Fig. 5 F) (width: 25.7% HL) subterminal, large portions of upper and lower jaws visible. Lips thin, smooth, crescentic, continuous around corners of mouth; widest at corners of mouth. Lower lip medially interrupted; the chin extending to most anterior portion of lip. Rostral and postlabial grooves present. Two pairs of rostral barbels, 1 pair of maxillary barbels. Medial-rostral barbels widely separated from one another, distance equal to that of medial interruption of lower lip. Medial and lateral-rostral barbels unequal in size, separated by distance about equal to length of lateral-rostral barbel. Lateral-rostral barbel not reaching base of the barbel, maxillary barbel reaching horizontally to vertical at anterior nostril. Gill opening extends to ventral surface of body. Dorsal fin (base length: 9.7% SL, length: 18.5% SL) originates posterior to pelvic-fin base and closer to caudal-fin base than to snout (predorsal length: 54.3% SL). Pectoral fin (length: 26.8% SL) longer than head, not reaching pelvic-fin origin. Pelvic fin (length: 20.8% SL) lacks axillary pelvic lobe, not reaching anus; anus closer to anal-fin origin than to pelvic-fin insertion. Anal fin length 13.5% SL. Adipose keel on caudal peduncle. Caudal peduncle length 15.9% SL, depth 9.0% SL. Caudal fin truncate.

Body scaled except for ventral surface anterior to pelvic-fin insertion. Scales small, smooth, not obvious to naked eye ( Fig. 4 F). Total lateral-line pores ca. 101, predorsal scales ca. 53, circumpeduncular scales ca. 60. Scales above and below lateral line ca. 18 and ca. 15, respectively. Scales below lateral line to pelvic-fin origin ca. 12. Dorsal-fin rays iii, 7½; anal-fin rays ii, 5; pectoral-fin rays vi, 9 for left side, and a total of 15 rays for the right side (right fin damaged; simple and branched rays could not be differentiated); pelvic-fin rays ii, 8 for left side and iii, 7 for right side; total caudal-fin ray count 16. Pores of cephalic lateralis system: 7 supraorbital, 5+11 infraorbital, 7 preoperculomandibular, and 3 supratemporal. Total vertebrae count 38 ( Fig. 16 B).

Coloration. In 70% ethanol: The specimen is faded, and the general color of the body is brown with a black stripe along the lateral-line. Herre (1945:400) gave the following description: “The color in alcohol is brown, the underside yellowish; 10 short dark brown bars across the back, but not extending down to the lateral-line; a poorly defined dark longitudinal stripe below the lateral line from the eye to the caudal base; top of head very dark brown; a blackish-brown spot on the ventral base; caudal with a blackish blotch on its base and another near its tip; other fins all clear.”

Distribution. The type locality is the Puthutotam Estate, brook in Anamallai Hills, southern India, elevation about 3,600 feet ( Fig. 17 ). This is in the state of Tami Nadu close to the border with Kerala, Coimbatore District; estimated coordinates are 10.36° N, 76.93° E. This drainage was reported to be adjacent and northeast to the Chalakudy basin by Pethiyagoda & Kottelat (1994:110).

Menon (1987) reported H. montana from Silent Valley and New Amarambalam of the Western Ghats, but this is likely H. pillaii (see Remarks). Arunachalam et al. (2002) examined an individual from Kerala at Malakkapara, headwaters of Chalakudy River. This specimen (KFRI F. 107) was not examined in this study, and this locality for H. montana cannot be confirmed.

Remarks. Menon (1987) recognized H. pillaii (spelled pillai) as a junior synonym of H. montana . Menon (1987) examined only the type series of H. pillaii but gave different counts than those in the original description (also see Pethiyagoda & Kottelat 1994:109). Many authors (Indra & Rema Devi 1981; Madhusoodana Kurup & Radhakrishnan 2010; Arunachalam et al. 2002; Silas 1953) have given a pectoral-fin ray count of iv, 8 for G. montana . The pectoral-fin ray count here and in the original description ( Herre 1945) is vi, 8.

Material examined. G. m o n t a n a: India: CAS-SU 39871 (holotype of Homaloptera montana ).

Figures

FIGURE 4. Scale sizes and keel patterns of predorsal region: Large, and keeled scales, (A) Balitoropsis zollingeri, UF 166094, 52.1 mm SL; (B) Pseudohomaloptera tatereganii, RMNH 7632 (holotype), 64.6 mm SL. Large, and wart-like / keeled scales (C) Homalopteroides wassinkii, UF 183330, 43.6 mm SL. Medium, and keeled scales, (D) Homaloptera cf. ocellata, UF 161718, 64.1 mm SL. Small, and smooth scales, (E) Homalopterula ripleyi, ANSP 188908, 43.1 mm SL; (F) Ghatsa montana, CAS-SU 39871 (holotype), 46.6 mm SL. Scale bar represents 1 mm. Left side of photo is anterior.

FIGURE 5. Oral morphology of (A) Homaloptera cf. ocellata, UF 161718, 64.1 mm SL; (B) Homalopteroides wassinkii, UMMZ 155660, 46.2 mm SL; (C) Homalopterula ripleyi, ANSP 188908, 43.1 mm SL; (D) Balitoropsis zollingeri, UF 166094, 52.1 mm SL; (E) Pseudohomaloptera tatereganii, RMNH 7632 (holotype), 64.6 mm SL; (F) Ghatsa montana, (holotype) CAS- SU 39871, 46.4 mm SL. Abbreviations: CF, central furrow; FL, fleshy lobe; FP, fleshy pad; LJ, lower jaw; LL, lower lip; LRB, lateral-rostral barbel; MB, maxillary barbel; MRB, medial-rostral barbel; RC, rostral cap; UJ, upper jaw; UL, upper lip.

FIGURE 16. Ghatsa montana, CAS-SU 39871 (holotype), 46.4 mm SL. (A) Dorsal, lateral, and ventral views, Puthutotam Estate, brook in Anamallai Hills, India; (B) radiograph. Photos by CAS, Ichthyology Section.

FIGURE 17. Type localities for species of Ghatsa. Asterisk represents the type species of the genus.