Garra surendranathanii SHAJI, ARUN & EASA, 1996

Etymology

Garra: vernacular Gangetic name for a particular species of “sand-digger,” which Francis Buchanan-Hamilton applied as a generic name for bottom-dwelling cyprinids “with no affinity to another genus”.

surendranathanii: named for Shri. P. K. Surendranathan Asari “Chief Conservator of Forests, Kerala Forest Department, who has been a constant source of encouragment to Wildife research activities in the state”.

Classification

Order: Cypriniformes Family: Cyprinidae

Distribution

Known only from the Chalakkudy, Periyar, and Pamba river basins in the state of Kerala, southwestern India.

Type locality is ‘ Orukomban, tributary to Chalakkudy River, 10°22’N, 76°41’E, Kerala, India, elevation 483 meters’.

Habitat

The type series was collected from a stream-like tributary of the Chalakkudy River at an altitude of 483 m AMSL. In March 1996 the habitat measured around 15 m across and comprised shallow (~ 20 cm deep) water flowing slowly through moist deciduous forest over a substrate of pebbles and boulders.

In the Periyar River the species has been collected from a perennial regulated stretch between two dams at approximately 720 m AMSL. The water flows slowly between large boulders and bedrock, and the area is generally highly-modified due to agriculture and other human activities.

In contrast, it has also been recorded in a fast-flowing tributary of the Pamba River with a rock and sand substrate at 160 m AMSL.

Maximum Standard Length

120 – 150 mm.

NotesTop ↑

G. surendranathanii has appeared in the aquarium trade on a handful of occasions and has been marketed as ‘green algae-eater’.

It has an elongate, shallow body shape (depth at dorsal-fin origin 12.5-16.23 % SL), and can be further diagnosed by the following combination of characters: snout with numerous, smooth tubercules, only a few with horn-like projections; no deep transverse groove at snout tip; inter-orbital region flat; two pairs of barbels; mental disc well-developed with width 6.28-7.14 % SL; anterior portion of breast scaleless; body scales with black edges; a black spot at upper extremity of opercle.

The genus Garra is a particularly enigmatic grouping with new taxa described on a regular basis, while many of the existing ones may represent cases of misidentification or synonyms of other species. Some of the revisions have also been called into question, which has added further confusion. A full generic review would be ideal but is unlikely to materialise given the extensive distribution of its members which range from southern China across much of southeast Asia, India and the Middle East as far as north/central Africa.

Instead a number of less-extensive works published in recent years have resulted in a gradual, but continuing, improvement in knowledge, and it remains possible that the genus will be broken up into smaller taxa since the current assemblage is almost certainly polyphyletic.

Garra species are usually included in the subfamily Labeoninae/Cyprininae or tribe Labeonini (name varies with author) which by recent thinking is further divided into four subtribes; Labeoina, Garraina, Osteochilina, and Semilabeoina (Yang et al., 2012). The putatively monophyletic Garraina comprises a number of genetic lineages including Garra sensu stricto (which also includes Horalabiosa, Phreatichthys and possibly other genera), a small clade comprising Garra cambodgiensis and G. fascicauda (thus rendering Garra polyphyletic), Paracrossocheilus, and Gonorhynchus (which includes Akrokolioplax).

Two Garra species, G. imberba and G. micropulvinus, are placed in the Semilabeoina assemblage, and the generic name Ageneiogarra Garman, 1912 has been suggested for them, although this does not appear to have been widely followed (e.g. Kottelat, 2013). In addition, some genera which were previously considered to be close relatives of Garra species such as Discogobio, Discocheilus and Placocheilus, are now also placed in this subtribe.

All genera currently included in Garraina possess a lower lip modified to form a mental adhesive disc, allowing the fish to cling to surfaces in turbulent conditions. In most species the upper lip is almost entirely reduced and both the upper and lower jaw margins are keratinised, i.e., horny, and used to scrape food items from the substrate.

Garra species are distinguished from other Garraina members by the first two pectoral-fin rays usually being thickened, fleshy and unbranched, possession of 10-11 dorsal-fin rays, and a combination of internal characters. Some species have evolved particular environmental specialisms such as highly reduced eyes in hypogean forms or the ability to survive in thermal springs.

References

1. Shaji, C. P., L. K. Arun and P. S. Easa, 1996 - Journal of the Bombay Natural History Society 93(3): 572-575
   Garra surendranathanii - a new cyrpinid fish from the southern Western Ghats, India.
2. Arunachalam, M. and S. Nandagopal, 2014 - Species 10(24): 43-57
   A new species of the genus Garra Hamilton, (Cypriniformes: Cyprinidae) from Nethravathi River, Western Ghats, India.
3. Arunachalam, M., M. Raja, S. Nandagopal and R. L. Mayden, 2013 - International Journal of Zoology Research 3(1): 62-68
   Garra palaruvica, a new cyprinid fish (Cypriniformes: Cyprinidae) from Kerala, Western Gnats, Peninsular India.
4. Stiassny, M. L. J. and A. Getahun, 2007 - Zoological Journal of the Linnean Society 150(1): 41-83
   An overview of labeonin relationships and the phylogenetic placement of the Afro-Asian genus Garra Hamilton, 1922 (Teleostei: Cyprinidae), with the description of five new species of Garra from Ethiopia, and a key to all African species.
5. Yang, L., M. Arunachalam, T. Sado, B. A. Levin, A. S. Golubtsov, J. Freyhof, J. P. Friel, W-J. Chen, M. V. Hirt, R. Manickam, M. K. Agnew, A. M. Simons, K. Saitoh, M. Miya, R. L. Mayden, and S. He, 2012 - Molecular Phylogenetics and Evolution 65(2): 362-379
   Molecular phylogeny of the cyprinid tribe Labeonini (Teleostei: Cypriniformes).
6. Zhang, E., 2005 - Zoological Studies 44(1): 130-143
   Phylogenetic relationships of labeonine cyprinids of the disc-bearing group (Pisces: Teleostei).