Metadata

Horaglanis krishnai

Menon 1950

Horaglanis krishnai
Redrawn by Rhian Kendall from Menon (1950)
ORDERSUB-ORDERFAMILY
SiluriformesSiluroideiClariidae

Synonyms

None.

Country

India

Types

Holotype: ZSI F313/2 38.85mm TL. The description is based on two specimens (second 42.0mm TL) and although the second is not mentioned as a paratype it should be considered as such (also at ZSI). This is the type species by original designation and monotypy of the cave‑restricted genus Horaglanis.

Distribution

Type locality: A well at an undisclosed location at Kottayam, Kerala, India. Known also from a number of dug out wells in the same area (8o4'N‑10o21'N, 76o13'E‑77o38'E). The type locality of this species is also the type locality of the Synbranchid Monopterus eapeni and at this site at least the two species coexist. It is not known whether they coexist elsewhere.

Habitat

The only published details are that the fish is found in dug-out wells. It may be an inhabitant of relatively small groundwater voids. Mercy (1981) suggests that they migrate from one well to another through the subsurface drainage system. Francy Kakkasery (pers. comm.) suggests that they live in the water table up to 10m below the surface and that they are only found where laterite is the predominant bed deposit.

Systematics

The anatomy of H. krishnai has been relatively well studied (see references below) and it seems certain that it is rather different in several ways from other members of the family. Menon (1950, 1951a, 1951b) suggested that the differences were the result of regressive evolution and that the animal was only secondarily primitive. Chardon (1968) made a thorough study of several aspects of siluriform anatomy. He noted that the viscera are more typical of the Bagridae than the Clariidae. This and other evidence suggests that the species is a relict, close to the stem of both Bagridae and Clariidae. Although admitting that there were examples of shared derived characters, and of features associated with hypogean life, Chardon suggested that it is primarily primitive. De Pinna (1998) postulates a relationship between Phreatobius and Horaglanis based on similar skull morphology. A recent photograph of Horaglanis krishnai (Plate 6) shows that it is blood red in colour, a very rare condition for fishes (De Pinna, 1998), as is Phreatobius and this may be a synapomorphy for a group containing the two genera. Clearly there is much to be learned about the exact systematic position of this interesting animal.

Conservation Status

MuG [DD:3.1:2011]

(Abraham, R. 2011. Horaglanis krishnai. The IUCN Red List of Threatened Species 2011: http://dx.doi.org/10.2305/IUCN.UK.2011-1.RLTS.T10261A3185783.en. Downloaded on 07 July 2017).

R (IUCN, 1990),  R (IUCN, 1993), VU D2 (IUCN, 1996, 2000). Dahanukar, Raut and Bhat (2004) assess this species as Critically Endangered but with any explanation of how they arrive at this status.

Museum Holdings

As above plus: BMNH 1981.11.20:1‑3.

Key References

Menon, A. G. K. Journal Article 1950 On a remarkable blind siluroid fish of the family Clariidae from Kerala, (India)
Menon, A. G. K. Journal Article 1951 Distribution of clariid fishes, and its significance in zoogeographical studies
Menon, A. G. K. Journal Article 1951 On certain features in the anatomy of Horaganis Menon
Eapen, K. C. Journal Article 1963 A new species of Monopterus from South India
Chardon, M. Journal Article 1968 Anatomie comparee de l'appareil de Weber et des structures connexes chez les Siluriformes
Misra, K.S. Book Section 1976 Horaglanis krishnai
Mercy, T. V. A. Journal Article 1981 The unique disposition of the valvula cerebelli in Horaglanis krishnai (Teleostei)
Mercy, T. V. A. Journal Article 1982 On the presence of a forked barbel in the blind catfish Horaglanis krishnai Menon
Mercy, T. V. A., Padmanabhan, K. G. and Pillai, N. K. Journal Article 1982 Morphological studies on the oocytes of the blind catfish Horaglanis krishnai Menon
Mercy, T. V. A. Journal Article 1983 Studies on the air bladder of blind clariid Horaglanis krishnai Menon
Mercy, T. V. A., Pillai, N. K. and Balasubramonian, N. K. Journal Article 1984 Studies on the oxygen consumption of the blind catfish Horaglanis krishnai
Mercy, T. V. A. and Pillai, N. K. Journal Article 1984/5 The anatomy and histology of the alimentary tract of the blind cat-fish Horaglanis krishnai
Talwar, P. K. and Jhingran, A. G. Book Section 1992 Genus Horaglanis and species Horaglanis krishnai
de Pinna, M. C. C. Book Section 1998 Phylogenetic relationships of Neotropical Siluriformes (Teleostei: Ostariophysi): Historical overview and synthesis of hypotheses
Mercy, TVA Book Section 2000 Biology of an endemic blind catfish Horaglanis krishnai Menon
Mercy, T. V. A., Pillai, N. K. and Balasubramonian, N. K. Journal Article 2001 Studies on certain aspects of behaviour in the blind catfish Horaglanis krishnia Menon
Mercy, T. V. A. and Pillai, N. K. Journal Article 2001 Studies on the cranial osteology of the blind catfish Horaglanis krishnai menon (Pisces, Clariidae)
Dahanukar, N, Raut, R and Bhat, A Journal Article 2004 Distribution, endemism and threat status of freshwater fishes of the Western Ghats of India
Subhash Babu, K.K. and Nayar, C.K.G. Journal Article 2004 A new species of the blind fish Horaglanis Menon (Siluroidea: Clariidae) from Parappukara (Trichur District) and a new report of Horaglanis krishnai Menon from Ettumanur (Kottayam District), Kerala
Dahanukar, N, Raghavan, R, Ali, A, Abraham, R and Shaji, CP Book Section 2011 Chapter 3. The status and distribution of freshwater fishes of the Western Ghats
Subhash Babu, K.K. Journal Article 2012 Horaglanis abdulkalami, a new hypogean blind catfish (Siluriformes: Clariidae) from Kerala, India
Raghavan, R., Das, K, Nameer, PO, Bijukumar, A and Dahanukar, N Journal Article 2016 Protected area and imperriled endemic freshwater biodiversity in the Westren Ghats hotspot
Pavan-Kumar, A Journal Article 2017 Molecular phylogeny of genus Horaglanis (Indian blind catfishes) within Family Clariidae