Nemacheilus keralensis

Rita, Banarescu & Nalbant, 1978

Synonyms: Noemacheilus keralensis Rita, Banarescu & Nalbant, 1978,
Oreonectes keralensis Rita, Banarescu & Nalbant, 1978

Order: Cypriniformes
Family: Balitoridae
Genus: Nemacheilus

Environment: Freshwater; benthopelagic
Climate: Tropical

Description: D iii 7; A ii 5; P i 10; V i. Body elongate, subcylindrical, of uniform depth. Head strongly depressed, much wider than deep.  Eyes small, not visible from underside of head.  Lips fleshy, lower one furrowed and incompletely interrupted in the middle by a narrow and only superficial groove. Nostrils close to each other, anterior nostril prolonged into long nasal barbels. The nasal barbels reaching up to the anterior border of eye. Dorsal fin inserted nearer base of caudal fin than tip of snout, pelvic origin in advance of dorsal fin insertion. Body completely covered by scales, lateral line short, ending above middle of pectoral fins. Dorsal and ventral adipose crest on the caudal peduncle, caudal fin rounded.

Distribution: Asia –  India: Western Ghats, western slope of Kerala State; Rajamalai and Karintiri areas of Periyar, Vagamon area of Menachil and Kaitapara area of Muvattupuzha rivers.

Habitat/Biology: Torrential streams.  Eravikulam national park and Karintiri area of Periyar, Kaitapara area of  Muvattupuzha and Vagamon area of Meenachil rivers. It was collected only from  high altitude streams with low temperatures (850 to 2200 m above msl.). Almost all the streams are with bedrock bottom, followed by cobble, gravel, sand and mud. Land use pattern at the collection site was reserve forest, with grasslands and tea plantation in Periyar river, reserve forest with cardarnon plantation in Muvattupuzha river and tea plantation in Meenachil river. All the streams are narrow with average stream depth less than 20 cm. Nemacheilus kerulensis, the priamry food item observed in the gut contents are algae  (48%), invertebrates (33%) and little amount of plants with detritus.  Large quantities of red algae Batrachospermum is identified from the collection site of N. kerulensis (Vagamon  area of Meenachil river). They are mostly attached to the rocky or sandy bottom of the streams.



Travaux du Museum d’Histoire Naturelle   ” Grigore Antipa” v. 19, p. 185-188 – 1978.
Article: *Oreonectes (Indoreonectes) keralensis* a new subgenus and species of loach from Kerala, India (Pisces, Cobitidae).



On décrit une nouvelle espèce de loche de l’état de Kérala dang le bassin de la Mer d’Arabie: Oreonectes keralensis Rita et Nalbant, Cette espèce et O. evezardi sont atribuées à un nouveau sous-genre: Indoreonectes Rita et Bânàrescu.

The first author collected, from a tributary of Periyar R., Kerala State, seven specimens of Noemacheiline loaches which differ much from all other loaches inhabiting the same area. It is closer to Noemacheilus evezardi DAY, a species now ascribed to the genus Oreonectes (Banarescu & Nalbant, 1968), The new species, too, is included within Oreonectes and ascribed to a new subgenus.

Genus Oreonectes Günther, 1868
A comprehensive diagnosis of the genus was given by Bânàrescu & Nalbant (1968) ; it must be added to it that the lateral line is incomplete or totally lacking.

Four subgenera can be recognized within Oreonectes

Oreonectes s. str.: nostrils distant, anterior one immediately in front of eye; no lateral line; nasal barbel comparatively short, reaching only to anterior margin of eye; posterior  free part of the air blader large, in direct contact with the bony capsule of the anterior part; body with dots or a longitudinal stripe, without crossbars, South China. Two species: Platycephalus and sayu.

Lefua Herzenstein, 1888: nostrils distant, anterior one immediately in front of eye; no lateral line; nasal barbels long, reaching at least to the middle of eye; free posterior part of the air bladder large, connected to the bony capsule by a long and narrow duct; a longitudional dark stripe and small dots; not crossbars. Northern East Asia. Three species costata, echigonia, nikkonis.

The Indonesian O. obesus represents a third subgenus the description of which will be given in a subsequent paper.

Indoreonectes Rita and Bânàrescu subg. nov. Derivatio nominis: after India; gender: masculin.

Type species: Oreonectes keralensis Rita and Nalbant sp. nova. Nostrils close to each other, posterior one distant from eye; lateral line present, short; length of nasal barbels variable; free posteriorpart of air bladder rudimentary; crossbars on body sides Southwest India (western Ghats).
Two species: keralensis, evezardi. Oreonectes keralensis Rita and Nalbant species nova

Derivatio nominis: after the State of Kerala.

Holotype: Institutul de Stiinţe Biologice Bucureşti nr. 2925, 32, 8 mm St. length; locality: Pampadampara,  in a small rivulet tributary to Periyar R., Arabian Sea basin, Kerala State, India. Paratypes: six specs., 22.8 to 35.8 mm st. length, same locality (two in the Institutul de Stiinţe Biologice Bucureşti, nr. 2934, one in the Natural History Muséum „Gr. Antipa”, no. 237, three in the Zoological Survey of India, Calcutta).

D 3/7; A 2/5.

Description: Body of almost uniform depth, thick anteriorly, compressed posteriorly; maximum body depth 14.9—18.0% st. length: length of caudal peduncie less than maximum depth, 13.5 — 16.2% of st. length; least depth 10.7—12.3%; body width 83 — 94% of maximum depth. Dorsal fin with 7 branched rays, its insertion closer to root of caudal than to tip of snout, in most specimens about equidistant between anterior margin of eye and root of caudal; origin of pelvics in advance of that of dorsal. Predorsal distance 50.7 — 57.0% of st. length; preanal distance 74.0 — 78.0% ; prepelvic distance 47.1 — 53.0%; distance from pectoral to pelvic insertion 26.8 — 30.4%; distance from pelvic to anal insertion  22.4 — 25.6%. Distance from dorsal insertion to base of caudal 78—93% of predorsal distance. Paired fins short (pectoral 17.1—20.4%, pelvic 14.9 — 18,3%), rounded. Edge of dorsal and anal convex, margin of caudal rounded. Length of caudal fin 17.9 — 21.2% of st. length; height of dorsal 14.9 — 18.3; of anal 14.2 — 18.3%; base of dorsal 10.7—12.2%; of anal 8.4—9.8%. Anus at short distance from the anal fin. Rather well developed dorsal and ventral adipose keels in the posterior part of the caudal peduncle. Body completely covered by scales. Lateral line very short, ending above the middle of the pectoral.

Head strongly depressed, much wider than deep; head length 22.8 — 26.0 of st. length. Snout blunt 8.3-10.7% of st. length and 35.8-41.0% of head. Eyes on the dorsal face of head, small and distant; eye diameter 2.7—3.9% of st. length, 12.0-15.7% of head, 28.2-44.0% of interorbital width. Nasal barbels shorther than in most other species of the genus, reaching to or quite slightly beyond  the anterior margin of eye. Lips fleshy, lower one furrowed and incompletely interrupted in the middle by a narrow and only superficial groove (Fig. 1 b.). The two lobes of the air bladder capsule high (Fig. 1 c.).

Body sides marked by numerous, very narrow, unsharply delimited, often interrupted, incomplete and ramified crossbars. These do not extend to the dorsal side of the body which is uniformly dark. Top and sides of head with very numerous minute blackish ponctuations. A black mark on the first ray of the dorsal, lying somewhat high, not just at the base of the fin. A narrow, unsharply delimited stripe or two distant spots on the base of the caudal; a few larger, irregular spots in the proximal part of the caudal.

In one paratype the head and the anterior part of the body are covered by numerous large, whitish tubercles, irregularly arranged, some on a few pectoral rays, some even on barbels. We wonder if these are due to same parasite or are breeding tubercles. Breeding tubercles occur in the males of many species of Neomacheilinae belonging to several genera; but these are much smaller, regularly arranged, etc. No breeding tubercles occur in the other species of Oreonectes; we examined enough specimens from most of them to assert this absence with certainty.

Comparative remarks. This new species is closer to O. evezardi but differs nevertheless sharply from it. In evezardi the nasal barbels are longer, reaching at least to the middle of eye, the pelvic origin lies exactly under that of the dorsal, the lower lip is more deeply interrupted in the middle (Fig. 2 a), the air bladder capsule less high (Fig. 2 b), the crossbars are wider, well delimited, regular and extend also on the dorsal side of the body, the blackish spot lies on the dorsal base, the top of the head is covered by large roundish brown spots, etc.

O. evezardi occurs in the northern part of the Western Ghats and adjacent hill ranges, in the basin of Kistna R. (type locality: Poona), of Codavari R., probably also in adjacent rivers flowing westwards. O. keralensis lives on the contrary in the soutern part of the Western Ghats, in the basin of Periyar R.; it may occur in the Kavery R. basin, too. It seems quite probable that the so-called evezardi recorded by Hora & Law (1941) just from Pampadampara type locality of O. keralensis and from two neighbouring localities, actually are O. keralensis.


The first author expresses her gratitude to Prof. Dr. N. Balakrishnan Nair, MA, Ph. DD, Se, FZS, FNA, Head of the Department of Aquatic Biology and Fisheries, for suggesting the problem of study of loaches of Kerala and for providing facilities for research.


1. BÂNÂRESCU (P.), NALBANT (T.), 1968 — Cobitidae (Pisces, Cypriniformes) collected by the
German India Expedition. Mitt. Hamburg Zool. Mus, Inst., 65:327 — 351. 2.
2. DAY (F.), 1878 — The Fishes of India. London.
3. HORA (S. L), LAW (N. C), 1941 — The Freshwater Fish of Travancore. Rec. Indian Mus., 43: 233—256.




Journal of the Bombay Natural History Society v. 99 (pt 1): 127-129.

Hora and Law (1941) reported evezardi from Periyar River at Pambadumpara in Travancore Hills of Kerala and remarked on the variations exhibited in the colour pattern in this species. Subsequently, Rita et al. (1978) described O. (I.) keralensis from Periyar River at Pambadumpara, distinguishing the species from evezardi based on differences in colour pattern and relative lengths of nasal barbels. The nasal barbels are longer in evezardi, extending to middle of eye, whereas in keralensis it is said to be shorter reaching up to the anterior border of eye. The vertical bands on the body are broad and brown, and interrupted or incomplete, extending from the dorsal to the ventral side of the body in evezardi, whereas in keralensis these are narrow, dark and entire on the upper half of the body and often split below the lateral line into streaks or spots. Rita et al. (op. cit.) remarked on the probability of Hora and Law’s specimens being keralensis. Menon (1987) included Pamba drainage in the distribution of keralensis, based on his study of fish collections from Sabarigiri hills.

A study of loaches from the earlier collections, especially from Cardamom Hills in southern Western Ghats by Dr. G. U. Kurup in 1969, from Sabarigiri Hills by Dr. R. S. Pillai in 1981 and recently in 1999 from Periyar river by Mr. Chandran and other collections received for identification from Muvattupuzha and Santhamparai have all revealed the presence of keralensis and not evezardi in these areas. We reiterate the view of Rita et al. (1978) that the species present in the Travancore Hills is keralensis. Also, the specimens reported as evezardi from Periyar by Chacko ( 1948) before the description of keralensis and those reported by Zacharias et al. (1996), mostly based on Chacko (op. cit.),  could also be keralensis. Biju et al. (2000) reported the occurrence of this species in Eravikulam National Park and Muvattupuzha river, from the cold waters at an altitude of 1050 m in Muvattupuzha river and at a range of 1600-2200 m in Periyar river. From the abowe records, the present distributional range of keralensis is in the Periyar drainage, the Muvattupuzha river down to the Pamba river in the southern Western Ghats.

 It can be concluded that evezardi has a wider distribution in the Northern and Central Western Ghats above the Palghat gap and in the Satpura Range, whereas its congener is restricted to the higher ranges of the  southern Western Ghats below the Palghat gap.