Indoreonectes evezardi

(Day 1872) Kottelat 1990

Indoreonectes evezardi
Redrawn by Rhian Kendall from Talwar and Jhingran (1992)
CypriniformesCobitoidei Nemacheilidae


Noemacheilus evezardi was described from epigean specimens by Day (1872). The first published account of their presence in a cave is that of Thines (1969:89) who reported information supplied to him by A. M. Agarwal. Greenwood (1976) also mentioned this species and disagreed with the previous two authors about the relative eye sizes of some of the specimens. More recently various studies have been made (see references below). Critically see the notes under Systematics below.


Noemacheilus evezardi  Day 1872

Nemachilus evezardi  Day 1936 (Thines (1969) misspelling and incorrect date)

Nemacheilus evazardi  (Bhargava, Jain and Singh (1984) misspelling)

Oreonectus evezardi  (Biswas (1989) misspelling)

Nemacheilus aureus  Shriavstava and Saxena (1988)




The cave form has no formal taxonomic status and there are no types.


The only published hypogean location for this species is Kotomsar Cave, (also Gupansar, Kutumsar, Kotamsar, Kutumbsar), Bastar District, Madhya Pradesh, India (18o52'10"N, 81o56'04"E).


Skalski (1990) provides a description and survey of Kotomsar Cave together with pertinent biological observations. The cave is 660m long and lies at an altitude of 580m. In wet weather water flows through the cave but as the water drops in the dry season pools are left behind. These are traps for the fishes which are numerous. Biswas and his colleagues consider this species to be a troglophile. It is at least as likely that the hypogean population is a distinct entity which is either phylogenetically young, or hybridised with a sympatric epigean congeners.


The cave dwelling fish from Kotomsar Cave is certainly not Indoreonectes or Nemacheilus evezardi. DNA analysis by Keskar et al (2018) showed conclusively that "Indoreonectes evezardi" is a species complex and true I. evezardi is only present in the upper reaches of Bhima River system. So it is not possible that the species from Madhya Pradesh can be the same species. It may be a hypogean population of an epigean species in the region or a new, undescribed, species.

Conservation Status


The population of fishes from Kotomsar Cave has not been evaluated. Skalski (1990) records that the fishes were numerous in all pools in the cave.

Museum Holdings

BMNH 1960.6.2:1‑2 (Greenwood 1976), ZSM 6439, ZSM/CMK 5992 3 specimens (Kottelat 1990).

Key References

Thines, G. Book 1969 L'Evolution regressive des poissons cavernicoles et abyssaux
Greenwood, P. H. Journal Article 1976 A new and eyeless cobitid fish (Pisces, Cypriniformes) from the Zagros Mountains, Iran
Bhargava, H.N., Jain, A.K. and Singh, D. Journal Article 1984 On background related chromatic response in the cave fish Nemacheilus evazardi (Day)
Pradhan, R.K. Thesis 1984 Biochemical studies of some tissues of Nemacheilus evezardi Day from Kotumsar Cave
Pradhan, R.K. and Agarwal, S.M. Journal Article 1984 Studies on Nemachilus (sic) evezardi Day from Kotumsar Cave. I Chromatophores
Zargar, V. N. and Ghosh, N. Book Section 1987 Observations on the behaviour of troglophilic microphthalmic fish Nemacheilus evezardi (Day) with relation to light
Biswas, J., Pati, A.K., Pradhan, R.K. and Kanoje, R.S. Journal Article 1988 Reproductive phase-dependant adjustment in behaviour circadian rhythm characteristics: an example of constructive evolution in hypogean fish
Shriavstava, S. and Saxena, A.B. Journal Article 1988 Effects of CuSO4 on the tissue respiration of the blind cave fish (Nemacheilus aureus) (Day) from Bastar (M.P.)
Pradhan, R.K., Pati, A.K. and Agarwal, S.M. Journal Article 1989 Meal scheduling modulation of circadian rhythm of phototactic behaviour in cave dwelling fish
Biswas, J. Journal Article 1989 Multifrequency rhythms in air gulping behaviour of cave fishes: an example of behavioural divergence
Biswas, J., Pati, A.K. and Pradhan, R.K. Journal Article 1990 Circadian and circannual rhythms in air gulping behaviour of cave fish
Skalski, A. W. Journal Article 1990 Some observations on the fauna of Kotosmar Cave in India (Bastar, Madhya Pradesh)
Kottelat, M. Book 1990 Indochinese nemacheilines. A revision of nemacheiline loaches Pisces, Cypriniformes) of Thailand, Burma, Laos, Cambodia and southern VietNam
Biswas, J., Pradhan, R.K. and Pati, A.K. Journal Article 1990 Studies on burying behaviour in epigean and hypogean fish, Oreonectes evezardi: an example of behavioural divergence
Biswas, J., Pati, A.K., Pradhan, R.K. and Kanoje, R.S. Journal Article 1990 Comparative aspects of reproductive phase dependant adjustments in behaviour rythms in epigean and hypogean fish
Biswas, J. Thesis 1990 Biospeleology: The behavioural and physiologic adaptations in a cavernicole
Biswas, J. and Pati, A.K. Journal Article 1991 Influence of thyroid hormones on muscle tissue respiration in hypogean and epigean populations of loach Oreonectus evezardi
Biswas, J. Journal Article 1991 Metabolic efficiency and regulation of body weight: A comparison between life in hypogean and epigean ecosystems
Biswas, J. Journal Article 1991 Annual modulation of diel motor activity rhythm of a dusk active loach Nemacheilus evezardi (Day): A correlation between daylength and circadian parameters
Biswas, J. Journal Article 1992 Influence of epigean environmental stress on a subterranean cave ecosystem: Kotumsar
Talwar, P. K. and Jhingran, A.G. Book Section 1992 Nemacheilus evezardi Day
Biswas, J. Journal Article 1992 Kotumsar Cave ecosystem: An interaction between geophysical, chemical and biological characteristics
Biswas, J. Journal Article 1993 Constructive evolution: Phylogenetic age related visual sensibility in the hypogean fish on Kotumsar Cave
Pradhan, R.K. and Biswas, J. Journal Article 1994 Towards regressive evolution: The periodic colour change behaviour of the troglophilic fish Nemacheilus evezardi Day
Pradhan, R.K. and Biswas, J. Journal Article 1994 The influence of photoperiods on the air-gulping behaviour of the cave fish Nemacheilus evezardi (Day)
Pati, A.K. Journal Article 2001 Temporal organisation in locomotor activity of the hypogean loach, Nemacheilus evezardi, and its epigean ancestor
Pati, A.K. and Agrawal, A. Journal Article 2002 Circadian rhythm in phototactic behaviour in a cave loach, Nemacheilus evezardi
Pati, A.K. and Agrawal, A. Journal Article 2002 Studies of the behavioural ecology and physiology of a hypogean loach, Nemacheilus evezardi, from the Kotumsar Cave India
Biswas, J Journal Article 2004 Behavioural rhythms in cavernicolous loach N. evezardi: suspected role of weak Zeitgebers
Diwan, HD, Gupta, MP and Bandhu, J Journal Article 2004 Perspective geomorphic analysis of Kotumsar karstic cave zone, Kanger Valley, Chhattisgarh (India)
Sahu, S., Das, K., Tirkey, J., Pattanaik, S., Chainy, G.B.N. and Adhikart, S.P. Journal Article 2004 Isolation and characterisation of microrganisms from Kotumsar and Gupteswar caves
Sinha, S and Naik, ML Journal Article 2004 Aquatic biodiversity of food chain link in Kotumsar Cave
Pati, AK, Agrawal, A and Parganiha, A Journal Article 2004 Update on circadian timing system (CTS) in Nemacheilus evezardi
Pradhan, R.K., Ramteke, A., Soni, R. and Kar, A. Journal Article 2004 Circadian variation in the levels of intermediary metabolites and enzyme activity in important tissues of the cave loach Nemacheilus evezardi
Parganiha, A., Ramteke, A., Kar, A. and Pati, A.K. Journal Article 2006 Background light intensity modulates circadian rhythm of phototactic behaviour in the cave loach, Nemacheilus evezardi.
Pati, A.K. Book Section 2008 Circadian rhythms in hypogean fish: With special reference to the cave loach, Nemacheilus evezardi
Agrawal, A. Journal Article 2008 Phototactic behaviour in cave populations of Nemacheilus evezardi with special reference to light intensity and feeding schedules
Biswas, J. and Ramteke, A.K. Journal Article 2008 Timed-feeding synchronizes circadian rhythm in vertical swimming activity in cave loach, Nemacheilus evezardi
Biswas, J Journal Article 2009 Kotumsar Cave biodiversity: A review of cavernicoles and their troglobiotic traits
Baskar, S., Swati, C. and Baskar, R. Journal Article 2018 Calcite precipitation by Rhodococcus sp. isolated from Kotumsar cave, Chhattisgarh, India
Keskar, A., Raghavan, R., Paingankar, M.S., Kumkar, P., Katwate, U., Jadhav, S., Padhye, A. and Dahanukar, N. Journal Article 2018 Molecular phylogeny unveils hidden diversity of hillstream loaches (Cypriniformes: Cobitoidea) in the northern Western Ghats of India
Band, S., Yadava, M.G., Lone, M.A., Shen, C.C., Sree, K. and Ramesh, R. Journal Article 2018 High-resolution mid-Holocene Indian summer monsoon recorded in a stalagmite from the Kotumsar Cave, central India
Laskar, B.A., Kundu, S., Sulthana, R., Adimalla, H., Jaiswal, D., Tyagi, K., Kumar, V. and Chandra, K. Journal Article 2021 Molecular investigation of cavernicoles from Kotumsar Cave in Northern Eastern Ghats, India