Distribution, threats and conservation status of Hypselobarbusthomassi (Day, 1874), a poorly known cyprinid fish of the Western Ghats freshwater ecoregion

 

Anvar Ali 1, Siby Philip 2, Neelesh Dahanukar 3, C.R. Renjithkumar 4, A. Bijukumar 5 & Rajeev Raghavan 6

 

1,2,6 Conservation Research Group (CRG), St. Albert’s College, Kochi, Kerala 682018, India

2 Department of Zoology, Nirmalagiri College, Koothuparambu, Kannur, Kerala 670701, India

3 Indian Institute of Science Education and Research (IISER), Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India

4 School of Industrial Fisheries (SIF), Cochin University of Science & Technology (CUSAT), Kochi, Kerala 682016, India

5 Department of Aquatic Biology & Fisheries, University of Kerala, Trivandrum, Kerala 695581, India

3,6 Systematics, Ecology & Conservation Laboratory, Zoo Outreach Organization (ZOO), 96 KumudhamNagar, Vilankurichi Road, Coimbatore, Tamil Nadu 641035, India

1 anvaraliif@gmail.com, 2 siby@conservationresearchgroup.com,3 n.dahanukar@iiserpune.ac.in, 4 renjith.kumar347@gmail.com,5 abiju@rediffmail.com, 6 rajeevraq@hotmail.com (corresponding author)

 

 

Abstract: The Red CanareseBarb, Hypselobarbus thomassi (Day, 1874) is an endemic cyprinid fish of the rivers of the Western Ghats of India, which has been listed as ‘Critically Endangered’ in the IUCN Red List of Threatened Species.  Like many of its congeners, H. thomassi is poorly known with very few verified records and voucher specimens in the past decades.  Based on fresh materials collected from three west flowing rivers of Kerala, we provide information on its identity, distribution, phylogenetic position, threats and conservation.  An updated conservation assessment of this species following the IUCN Red List criteria is also provided.

 

Keywords: Barb, freshwater fish, Gonoproktopterus, India, IUCN Red List.

 

 

 

doi: http://dx.doi.org/10.11609/JoTT.o3838.5202-13  | ZooBank:urn:lsid:zoobank.org:pub:4AC19BCE-A83C-495E-819B-76D89EF5DDE9

 

Editor: Topiltzin Contreras MacBeath, Universidad Autónomadel estado de Morelos, México.   Date of publication: 26 December 2013 (online & print)

 

Manuscript details: Ms # o3838 | Received 02 November 2013 | Final received 17 December 2013 | Finally accepted 18 December 2013

 

Citation: Ali, A., S. Philip, N. Dahanukar, C.R. Renjithkumar, A. Bijukumar & R. Raghavan (2013). Distribution, threats and conservation status of Hypselobarbus thomassi (Day, 1874), a poorly known cyprinid fish of the Western Ghats freshwater ecoregion. Journal of Threatened Taxa 5(17): 5202–5213; http://dx.doi.org/10.11609/JoTT.o3838.5202-13

 

Copyright: © Ali et al. 2013. Creative Commons Attribution 3.0 Unported License. JoTT allows unrestricted use of this article in any medium, reproduction and distribution by providing adequate credit to the authors and the source of publication.

 

Funding: Rajeev Raghavan thanks the Mohammed Bin ZayedSpecies Conservation Fund (MBZSCF; Project 1225670) and the North of England Zoological Society (NEZS), Chester Zoo for funding the project on ‘Lost fishes of the Western Ghats’. Neelesh Dahanukar is supported by the Inspire Faculty Fellowship of the Department of Science and Technology (DST), Government of India.

 

Competing Interest: The authors declare no competing interests. Funders had no role in study design, collection, analysis and interpretation of data and manuscript writing.

 

Author Contribution: AA, SP, CRR, AB & RR carried out the field work and collected the specimens; RR studied museum specimens; AA performed morphometry, ND carried out the extraction of DNA and related molecular laboratory work; SP carried out the phylogenetic analysis; AA, SP, ND, AB & RR wrote the manuscript.

 

Author Details: Anvar Ali is interested in taxonomy and systematics of freshwater fishes of the Western Ghats. Siby Philip is interested in molecular phylogenetics, evolution and biogeography of freshwater fishes of the South Asia region. Neelesh Dahanukar works in taxonomy, ecology and evolutionary biology of fishes and amphibians with emphasis on mathematical and statistical analysis. C.R. Renjithlumar works on diversity, distribution and conservation of freshwater fishes of the Kerala region of Western Ghats. A. Bijukumaris interested in biodiversity documentation and taxonomy, and involved in biodiversity/ environmental education activities to facilitate conservation. Rajeev Raghavanis interested in interdisciplinary research focused on generating information and developing methods to support conservation decision-making in freshwater ecosystems.

 

Acknowledgements: RajeevRaghavan thanks Ralf Britz, Natural History Museum (NHM), London for his help with the examination of Day’s materials, for photographs and useful discussions; Helmut Wellendorf, Natural History Museum, Vienna (NMW); Leo Smith and Kevin Swagel, Field Museum, Chicago (FMNH) for their help in providing photographs and radiographs of syntypes; AmbilyNair for her constant help and support; K. Krishnakumar,Fibin Baby and BennoPereira for assistance and logistics in the field.; AnvarAli, C.R. RenjithKumar, A. Bijukumarand Rajeev Raghavan thanks the local fishers in and around Chalakudy, Pooyamkuttyand Thenmala for the cooperation and help during the field work.

 

The publication of this article is supported by the Critical Ecosystem Partnership Fund (CEPF), a joint initiative of l’Agence Française de Développement, Conservation International, the European Commission, the Global Environment Facility, the Government of Japan, the MacArthur Foundation and the World Bank.

 

 

 

For figures, images, tables -- click here

 

 

Introduction

 

Hypselobarbus thomassi(Day, 1874) (Images 1 & 2) is a poorly known large cyprinid species endemic to the Western Ghats freshwater ecoregion in peninsular India (Devi & Ali 2011). Day (1874, p707) described Barbus (= Hypselobarbus) thomassi from South Canara as a large barb growing to more than 450mm in length.  Subsequently, Day (1878, p 567; 1889, p 311) provided additional notes on this species. Historic literature (Day 1874, 1879, 1889) suggested that this species is restricted in distribution to the inland waters of the erstwhile South Canara, i.e., the area encompassing current day Dakshin Kannada District of Karnataka, and Kasargod District of Kerala.

Like many other species within this genus, H. thomassihas also been poorly represented in collections, and not many records are available in the primary literature. The first record of H. thomassi outside its type locality was most likely made by Jayaramet al. (1976) from the rivers of the Cardamom Hills, as previous ichthyological surveys in Travancore (e.g., Pillai 1929; John 1936) and the AnamalaiHills (Silas 1951) had not mentioned this species. Subsequent compilations and checklists (for e.g., Talwar & Jhingran 1991; Menon 1999; Easa & Shaji 2003; Devi et al. 2005) provided the distribution range for H. thomassias South Canara and Cardamom Hills.  Later, many researchers added new records (although not supported by voucher specimens) of this species from various rivers in Kerala (see Table 1).

In the absence of recent records and contradictory claims made by researchers, the exact distribution range of H. thomassiremained uncertain.  Abraham et al. (2011) indicated that only three species of Hypselobarbus,viz., H. curmuca, H. kolus and H.kurali are present in river Kallada, and suggested that the reports of H. thomassi from this river are not correct and is a case of  misidentification (R. Abraham pers. comm. cited in Devi & Ali 2011). Hence, based on the assumption that H. thomassi, is restricted to an area of <10km2 as two fragmented locations in the Nethravati and Kabinirivers, this species was listed as ‘Critically Endangered/CR’ in the IUCN Red List of Threatened Species (see Devi & Ali 2011).  A recommendation for carrying out urgent surveys in the known areas of occurrence as well as validation of the identity of the southern Kerala populations was also made (Devi & Ali 2011).

Recently, Knight et al. (2013a) cleared the taxonomic ambiguity surrounding the identity of H. thomassi after making fresh collections from its type locality.  They also examined a single specimen of the species from the Athirapilly waterfalls in Chalakudy River, Kerala, and suggested that they are conspecific with the populations found in South Canara, its type locality; and that the claims made by Devi & Ali (2011) on the taxonomic distinctiveness of the Kerala population needs to be substantiated.

Based on specimens collected from the Chalakudy,Periyar and Kallada rivers as well as re-examining materials that formed the basis of the study of Abraham et al. (2010), we provide additional information on the current distribution range of H. thomassi in the Western Ghats freshwater ecoregion.  Based on the updated information on distribution and threats, we then propose an updated Red List assessment for this endemic species.

 

 

Materials and Methods

 

Materials examined

Hypselobarbus thomassi, CRG-SAC.2013.41, 13.vi.2013, 1 ex., 106.4mm SL, Vettilapara, 10.2870N & 76.4980E,Chalakudy River, Kerala, India, coll. R. Raghavan & A. Ali; Hypselobarbus thomassi, CRG-SAC.2013.72, 05.iv.2013, 1 ex., 138.31mm SL, Rosemalai, 8.9100N & 77.1640E, Kallada river, Kerala, India, coll. Renjith Kumar; Hypselobarbus thomassi, DABFUK F 15, 20.vi.2010, 1 ex., 83mm SL, Thenmala, 8.8740N & 77.1950E,Kallada River, Kerala, India, coll. A. Bijukumar; Hypselobarbus thomassi, CRG-SAC.2004.201, 04.iii.2004, 1 ex., 127.07mm SL, Pooyamkutty, 10.1690N & 76.7930E, Periyar River, Kerala, India, coll. R. Raghavan et al.

 

Photographs and X-ray

Barbus thomassi, F. Day, MCZ 4270, 1 ex, South Canara, India; Barbus thomassi, F. Day, FMNH 2317, 1 ex, South Canara, India; Barbus thomassi, F. Day, NMW 54767, 1 ex, South Canara, India (also radiograph - see Image 3); Barbus thomassi, F. Day, BMNH 1889.2.1.562, 1 ex, South Canara, India.

 

Museum abbreviations

BMNH: Natural History Museum, London; CRG-SAC: Conservation Research Group, St. Albert’s College, Kochi; DABFUK: Department of Aquatic Biology and Fisheries University of Kerala, Trivandrum; FMNH: Field Museum, Chicago; MCZ: Museum of Comparative Zoology, Harvard; NMW: Natural History Museum, Vienna.

 

Taxonomy

We use the generic name Hypselobarbusinstead of Gonoproktopterus following Arunachalam et al. (2012), Yang et al. (2012), and Knight et al. (2013a,b,c).

 

Morphometric data collection

Counts and measurements follow Pethiyagoda et al. (2012) and Knight et al. (2013a). Measurements were taken using a digital calliper to the nearest 0.1mm.  Subunits of body are presented as percent of standard length (SL) and subunits of head are provided as percent of head length (HL) (see Table 2).

 

DNA isolation and molecular phylogeny

Muscle tissue was harvested from a fresh specimen each collected from two different river systems, Chalakudy and Kallada in Kerala (CRG-SAC.2013.42, CRG-SAC.2013.72.1) and was preserved in absolute ethanol. The tissue was digested at 600C for two hours using the STE buffer (0.1M NaCl, 0.05 MTris-HCl, 0.01M EDTA, 1%SDS) with 15μl Proteinase K (20mg/ml) per 500ml of STE buffer. DNA was extracted using conventional phenol-chloroform method and re-suspended in nuclease free water.  Polymerase chain reaction was performed to amplify mitochondrial cytochrome oxidase subunit I (cox1) gene, using the forward primer Fish R1 (5’- TCAACCAACCACAAAGACATTGGCAC-3’) and reverse primer Fish R1 (5’- TAGACTTCTGGGTGGCCAAAGAATCA -3’) (Ward et al. 2005). PCR reaction was performed in a 25μl reaction volume containing 5μl of template DNA (~200ng), 2.5μl of 10X reaction buffer (100 mM Tris pH 9.0, 500 mM KCl, 15mM MgCl2, 0.1% Gelatin), 2μl of 25mM MgCl2, 1μl of 10mM dNTPs, 1μl of each primer, 1μl Taq polymerase (1U/μl) and 12.5μl nuclease free water. The thermal profile was 10 minsat 950C, and 35 cycles of 1 min at 940C, 1 min at 540C and 2 mins at 720C, followed by extension of 10 mins at 720C.  Amplified DNA fragments were purified using the ‘Promega Wizard Gel and PCR clean up’ system and sequenced.  The purified PCR products were sequenced using ABI prism 3730 sequencer(Applied Biosystems, USA) and Big dye terminator sequencing kit (ABI Prism, USA).

BLAST tool (Altschul et al. 1990) was used to analyze the integrity of the sequence.  The sequences were submitted to NCBI GenBank (accession numbers pending).  We retrieved additional sequences for other related species from NCBI GeneBank database (http://www.ncbi.nlm.nih.gov/).  GenBank accession numbers for the sequences used for the analysis are provided in Table 3 and Fig. 1.  Sequences were aligned using MUSCLE (Edgar 2004).  A Maximum Likelihood (ML) phylogeny was built in PHYML ver 3.0 (Guindon et al. 2010) using the dataset after finding out the best fit nucleotide substitution model using MrAIC (Nylander 2004).

 

 

Results and Discussion

 

Values of morphometric characters of the specimens that we collected (Table 2) are within the general range as observed in the putative topotypes studied by Knight et al. (2013a).  Whatever minor variations that were observed were due to the reason that closely related large growing cypriniform fishes, often tend to have an allometric growth pattern (Mina et al. 1996; Patimar & Farzi 2011), resulting in discrepancy in morphometric proportions (also see Ali et al. 2013).

 

Description

Body elongate, laterally compressed, dorsal profile convex with the pre dorsal contour ascending up to dorsal fin origin then descending gently towards caudal peduncle.  Ventral profile also convex anteriorly up to pelvic fin origin, almost flat up to anal fin base, then slanting sharply to the caudal base.

Head laterally compressed, eyes positioned somewhat superiorly, visible from dorsal and ventral aspects. Nares placed very close to the antero-superior rim of the orbit.  An elevated flap is present at the middle of the nares. Mouth sub-terminal, reaching to vertical at middle of nostrils, U shaped in ventral aspect with interrupted labial fold.  Two pairs of thin barbels; the rostral pair shorter than the maxillary one.  Rostral barbels, when adpressed reach the base of maxillary barbels and a point in vertical from the posterior extremity of the nostrils.

Dorsal fin origin above 10th scale of the lateral line and is slightly in advance of pelvic fin origin; sharply pointed at apex with a concave distal margin.  Posterior margins of pectoral and pelvic fins convex, curved not reaching to vertical from insertion of pelvic fin and anal fin respectively.  Anal fin with a concave distal margin; caudal fin deeply forked; both the lobes with pointed tips, upper lobe slightly longer than the lower one.

Dorsal fin with four simple and nine branched rays, the last one branched to the base.  Last unbranched dorsal fin ray longest followed by the first branched ray. Pectoral fin with one simple and 15 branched rays.  Pelvic fin with one simple and nine branched rays. Anal fin with three simple and five branched rays, last one branched to the base.  Caudal fin with 9+8 branched rays and 3-4 procumbent rays above and below the principal fin rays of each lobe.

Lateral line complete with 33–34 pored scales, plus one unperforated scale at the base of the caudal fin. Eleven predorsal scales (excluding the notched one at fin origin) and 14 circumpeduncularscales (½-3-1-2-½ scale in transverse line).  Transverse scale count between dorsal fin origin and pelvic fin origin ½+5+1+3 and 3½ scales between lateral line and anal fin.  There exist 21 pre ventral scales and 30 pre anal scales.  Dorsal base sheathed with 9–10 scales where as the anal fin with 5–6 scales.  One scale row between the urogenital opening and anal fin origin.  The two axillary scales present at the pelvic fin base exceed a bit beyond the posterior insertion of the fin.

 

Colouration

Dorsal side of the body and the flanks above the lateral line are greenish grey in colour and the flanks below lateral line and the ventral side are bright silvery in colouration. Body devoid of any distinct markings.  All the fins orange-red in colour at their proximal ends and with a greyish tinge at the distal ends.  Head, scales and rostral barbels with many minute scattered chromatophores but is absent on the maxillary barbels (when viewed under microscope).

 

Squamation

Observations from the present study as well as those carried out earlier on the genus Hypselobarbus have revealed that these large barbs have a wide range in their lateral line scale counts (for e.g., 31–36 in H. thomassi; 37–39 in H. lithopidos) (Day 1874; Ali et al. 2013; Knight et al. 2013a).

 

Distribution

Hypselobarbus thomassi is endemic to the Western Ghats of India (Dahanukar& Raghavan 2013).  It is currently known as fragmented populations from several small west flowing rivers in the Western Ghats freshwater ecoregion, viz., Kempuhole(Karnataka State) (Knight et al. 2013a), Chalakudy, Periyar and Kallada (Kerala State) (Image 4).  There are at least 26 west flowing and two east flowing river systems between Kempuhole and Chalakudy, and six west flowing and one east flowing river systems between Periyarand Kallada (see River Research Center2013 for a list of rivers in Kerala). However, comprehensive ichthyological surveys carried out during the last decade and a half (Kurupet al. 2004; River Research Center 2013 and references therein) have failed to record H. thomassifrom any of these rivers.  Although local knowledge of fishers in Chandragiri River reveal that the species is sometimes caught, there are no voucher specimens to confirm this. Nevertheless, the location of the Chandragiri basin in the larger South Canaralandscape (the type locality of the species) may actually mean that the species could be present in the river.  The records of H. thomassi from two east flowing river systems, Kabini River of Cauvery River system (Easa & Shaji 2003), and Tunga-Bhadra (Ahmad & Venkateshwarlu2012; Ahmad et al. 2013) and Mula-Mutha Rivers of Krishna River system (Wagh & Ghate2003), are difficult to verify as there are no voucher specimens.  It is also essential to note that the record of this species from Mula-Mutha River by Wagh & Ghate (2003), based on the collections made during 1992–1995, is likely to be wrong because the species was neither recorded during previous (Fraser 1942; Suter1944; Tonapi & Mulherkar1963), nor later (Kharat et al. 2001) studies.

Until reliable records backed up by voucher specimens are available from the east flowing rivers (Cauvery and Krishna), we considerer H. thomassi to be restricted to the west flowing rivers of the Western Ghats.  We therefore exclude the records of the species from east flowing drainages in the distribution map (Image 4).

 

Population status

Currently there is very little information on the population status of H.thomassi from its native range.  Menon (2004) mentioned that an extensive search in South Canara, the type locality H. thomassi, resulted in the collection of only one specimen. Local knowledge of fishers in the Chalakudyand Periyar rivers reveal that the fish is not common and is rarely caught.  Extensive surveys in the Kasargod District of Kerala State (erstwhile South Canara - type locality) including Chandragiri (Biju 2005) as well as neighbouring basins of Uppala and Manjeshwaram (Biju et al. 1999 a,b) did not yield any specimens of H. thomassi.  Although, Ramachandraet al. (2012) suggested that H. thomassi is extirpated from several west flowing rivers of Karnataka including Kali, Bedti, Aghanashini, Sharavati and Nethravati, Knight et al. (2013a) collected several specimens from Nethravatiindicating that the fish is still extant.

 

Habitat and Ecology

Hypselobarbus thomassi inhabits pool-riffle, run and glide habitats in fast to moderately flowing streams shaded with a fine amount of riparian vegetation.  It favours clear, well oxygenated water flowing gently over substrates that are extensively encountered in these microhabitats such as boulders, bedrocks and sand. The adults of the species always dwell in moderately deep pools, whilst the juveniles are seen in the shallow areas associated with the pool-riffle and run habitats.  The habitats of H. thomassi in the three river systems of Kerala are shown in Images 5–7.

 

Phylogenetic position

A genetic distance of 0.1% was observed between the cox1 sequence of H.thomassi, from the ChalakkudyRiver and Kallada River.  Interestingly, the sequence generated from the specimen collected from Kallada River (Fig. 1) demonstrates the uniqueness with a sequence from the GenBank(HM010715) which was deposited as H. lithopidos(from Rosemalai - also in the KalladaRiver system) (see Arunachalam et al. 2012).  These three sequences formed a monophyletic group (Fig. 1) which was sister to the topotypic sequences of H. lithopidoscollected for the present study. The average genetic distance between the sequence of topotypic H. lithopidos, collected from South Canara, and the H. thomassisequences were 4.85%.  This confirms that the sequence HM010715, collected from Rosemalai, is in fact H. thomassi and not H. lithopidos as argued by Arunachalamet al. (2012).  Our phylogenetic analysis and additional observations made in two recent papers (Ali et al. 2013; Knight et al. 2013a) demonstrates that Arunachalamet al. (2012) provides an inaccurate picture of the phylogenetic relationship of the genus Hypselobarbus.

 

Threats and conservation

To the best of our knowledge, there is no targeted fishery of H. thomassi as a food fish anywhere in its distribution range.  However, they are caught along with other species of Hypselobarbus as well as Mahseer (Tor sp.) in the Kallada River in Kerala.  Unmanaged aquarium trade (see Raghavan et al. 2013) is a concern as local fishers acknowledge the fact that juvenile H. thomassiare sometimes caught as by-catch during aquarium fish collections for its congener, H. jerdoni in the rivers of Dakshin Kannada and Kasargoddistricts of Kerala (=erstwhile South Canara).  Destructive fishing practices especially dynamiting is a major threat to the species in the streams around Pooyamkutty in Periyar River, as well as in Umayar, Rosemalaiand Katalapara regions of Kalladariver.  Poisoning and electric fishing are prevalent in the Sullia region of Dakshin Kannada, especially when the water levels are low (see Ali et al. 2013).

Currently, H. thomassi has been listed as ‘Critically Endangered’ (Devi & Ali 2011) in the IUCN Red List of Threatened Species based on limited distribution information available during the assessment.  Additional information on distribution, threats and taxonomic clarifications (Knight et al. 2013a; this paper) have led to a scenario where the conservation status of the species needs to be re-assessed.  The proposed Red List Status of the species has been provided in Appendix 1.

 

 

Conclusions

 

In spite of research that began more than two hundred years ago, our knowledge on the diversity and distribution of freshwater fishes of Western Ghats is far from complete.  Studies such as those reported in the present paper, as well as others (for e.g., Katwate et al. 2012; Ali et al. 2013; Emmanuel et al. 2013; Knight et al. 2013a,b,c;) are addressing this gap in knowledge on species distribution, widely termed as the ‘Wallaceanshortfall’ thereby facilitating the development and implementation of conservation policies and action in this exceptional region of freshwater biodiversity.

 

 

References

 

Abraham, R.K., N. Kelkar & A.B. Kumar (2011). Freshwater fish fauna of the Ashambu Hills landscape, southern Western Ghats, India, with notes on some range extensions. Journal of Threatened Taxa 3(3): 1585–1593; http://dx.doi.org/10.11609/JoTT.o2528.1585-93

Ahmad, S., M. Muralidharan, M. Venkateshwarlu & M. Arunachalam(2011). Distribution pattern, endemism, threat status and conservation measures of fishes in the Tunga and Bhadra rivers of Western Ghats, India. Environmental Biology of Fishes 96(10–11): 1245–1256; http://dx.doi.org/10.1007/s10641-011-9915-y

Ahmad, S. & M. Venkateshwarlu (2012). Habitat Ecology of Cyprinid Fish Community in Relation to Environmental Factors of Tunga and BhadraRivers, Western Ghats, Karnataka (India). Journal of Research & Development 12: 65–91.

Ali, A., S. Philip & R. Raghavan (2013). Back from obscurity: notes on the current distribution, threats and conservation status of a poorly known cyprinid, Hypselobarbus lithopidos (Day, 1874) from the Western Ghats of India. Journal of Threatened Taxa 5(13): 4743–4751; http://dx.doi.org/10.11609/JoTT.o3655.4743-51

Arunachalam, M., M. Raja, M. Muralidharan & R.L. Mayden (2012). Phylogenetic relationships of species of Hypselobarbus (Cypriniformes: Cyprinidae): an enigmatic clade endemic to aquatic systems of India. Zootaxa 3499: 63–73.

Beevi, K.S.J. & A. Ramachandran(2009). Checklist of freshwater fishes collected from Ernakulam District, Kerala, India. Journal of Threatened Taxa 1(9): 493–494; http://dx.doi.org/10.11609/JoTT.o1559.493-4

Biju, C.R. (2005). Habitat and Distribution of Hillstream Fishes of Northern Kerala (north of Palghat Gap). PhD Thesis. Mahatma Gandhi University, Kottayam, India.

Biju, C.R., K.R. Thomas & C. Ajithkumar (1999a). Freshwater fish distribution in the Manjeshwaram River, KasargodDistrict, Kerala, India. Journal of the Bombay Natural History Society 96(1): 159–161.

Biju, C.R., K.R. Thomas & C. Ajithkumar (1999b). Distribution of freshwater fishes in the Uppala River, Kasargod District, Kerala. Journal of the Bombay Natural History Society 96(2): 334–335.

Dahanukar, N. & R. Raghavan (2013). Freshwater fishes of Western Ghats: Checklist v 1.0 August 2013. MIN - Newsletter of IUCN SSC/WI Freshwater Fish Specialist Group - South Asia and the Freshwater Fish Conservation Network of South Asia (FFCNSA) 1: 6–16.

Day, F. (1874). On some new or little-known fishes of India. Proceedings of the Zoological Society of London 1873(3): 704–710.

Day, F. (1878). The Fishes of India; Being A Natural History of the Fishes Known to Inhabit the Seas and Fresh Waters of India, Burma, and Ceylon - Part 4. Beknard Quaritch: London, i-xx+553–579, pls. 139–195.

Day, F. (1889). Fishes. In: Blanford, W.T. (ed). The Fauna of British India including Ceylon and Burma. Taylor & Francis, London. v. 1: 1–xviii+1–548.

Devi, K.R. & A. Ali (2011). Hypselobarbus thomassi. In: IUCN 2013. IUCN Red List of Threatened Species.Version 2013.1. <www. iucnredlist.org>. Downloaded on 24 October 2013.

Devi, K.R., T.J. Indra, M.B. Raghunathan & M.S. Ravichandran(2005). Fish fauna of the Anamalaihill ranges, Western Ghats, India. Zoos’ Print Journal 20(3): 1809–1811; http://dx.doi.org/10.11609/JoTT.ZPJ.1164a.1809-11  

Easa, P.S. & C.P. Shaji(2003). Biodiversity Documentation for Kerala. Part 8. Freshwater Fishes. Kerala Forest Research Institute Handbook No 17. 127pp.

Edgar, R.C. (2004). MUSCLE: multiple sequence alignment with high accuracy and high throughput. Nucleic Acids Research 32: 1792–1797; http://dx.doi.org/10.1093/nar/gkh340

Emmanuel, J., K. Krishnakumar, B. Pereira, A. Kanagavel, A. Ali & R. Raghavan(2013). New records of the Endangered balitorid loach, Travancoria elongata Pethiyagoda& Kottelat 1994, from the Kerala part of the Western Ghats, India. Journal of Threatened Taxa 5(10): 4504–4509; http://dx.doi.org/10.11609/JoTT.o3407.4504-9

Fraser, A.G.L. (1942). Fish of Poona. Part I. Journal of the Bombay Natural History Society43(1): 79–91.

Guindon, S., J.F Dufayard, V. Lefort, M. Anisimova, W.Hordijk & O. Gascuel. (2010). New algorithms and methods to estimate maximum-likelihood phylogenies: assessing the performance of PhyML 3.0. Systematic Biology 59: 307–321; http://dx.doi.org/10.1093/sysbio/syq010

Jayaram, K.C. (2010). The Freshwater Fishes of The Indian Region. Revised 2nd Edition. NarendraPublishing House, 616pp+xxxixpls.

Jayaram, K.C. (1981). The Freshwater Fishes of India, Pakistan, Bangladesh, Burma and Sri Lanka - A Handbook. Zoological Survey of India. i-xxii + 1–475, Pls. 1–13.

Jayaram, K.C., T.J. Indra & M.S. Singh (1976). On a collection of a fish from the Cardamom Hills, south India. Madras Journal of Fisheries 7: 1–7.

John C.C. (1936). Freshwater fish and fisheries of Travancore. Journal of the Bombay Natural History Society 38(4): 702–733.

Katwate, U., R.Raut., M. Khot., M. Paingankar & N. Dahanukar (2012). Molecular Identification and Ecology of a Newly Discovered Population of Sun Catfish Horabagrus brachysoma from NorthernWesternGhats of India. ISRN Zoology, 2012: 1–9. http://dx.doi.org/10.5402/2012/419320  

Kharat, S.S., N. Dahanukar & R. Raut (2001). Decline of fresh-water fish of Pune urban area. Journal of Ecological Society13/14: 46–51.

Knight, J.D.M., A. Rai& R.K.P. D’souza (2013a). Re-description of Hypselobarbus lithopidos (Teleostei: Cyprinidae), based on its rediscovery from the Western Ghats, India, with notes on H. thomassi. Journal of Threatened Taxa 5(13): 4734–4742; http://dx.doi.org/10.11609/JoTT.o3602.4734-4742 

Knight, J.D.M., A. Rai& R.K.P. D’souza (2013b). Rediscovery of Hypselobarbus pulchellus, an endemic and threatened barb (Teleostei: Cyprinidae) of the Western Ghats, with notes on H. dobsoni and H.jerdoni. Journal of Threatened Taxa 5(17): 5194–5201; http://dx.doi.org/10.11609/JoTT.o3686.5194-201

Knight, J.D.M., A. Rai& R.K.P. D’souza (2013c). On the identities of Barbus mussullah Sykes and Cyprinus curmuca Hamilton with notes on the status of Gobio canarensis Jerdon (Teleostei: Cyprinidae). Zootaxa 3750(3): 201–215.

Kurup, B.M., K.V. Radhakrishnan & T.G. Manojkumar (2004).Biodiversity Status of Fishes Inhabiting Rivers of Kerala (South India) With Special Reference to Endemism, Threats and Conservation Measures. In: Welcomme, R.L & T. Petr. (eds),Proceedings of the Second International Symposium on the Management of Large Rivers for Fisheries 2 (LARS2), Cambodia, 310pp.

Menon, A.G.K. (2004). Threatened fishes of India and their conservation. Zoological Survey of India. Kolkatta, India, 170pp.

Menon, A.G.K.   (1999). Check list - fresh water fishes of India. Records of the Zoological Survey of India. Miscellaneous Publication, Occasional Paper No. 175: i-xxviii+1-366pp.

Mina, M.V., A.N. Mironovsky & Y. Dgebuadze (1996). LakeTana large barbs: phenetics, growth and diversification. Journal of Fish Biology 48(3): 383–404; http://dx.doi.org/10.1111/j.1095-8649.1996.tb01435.x

Nylander, J.A.A. (2004). MrAIC.pl. Program distributed by the author. Evolutionary Biology Centre, Uppsala University.

Patimar, R. & S. Farzi(2011). Life history and other biological traits of the trout barb Capoeta trutta in the River Meymeh(western Iran). Folia Zoologica60(2): 153–158.

Pethiyagoda, R., M. Meegaskumbura& K. Maduwage. (2012). A synopsis of the South Asian fishes referred to Puntius (Pisces: Cyprinidae). Ichthyological Exploration of Freshwaters 23(1): 69–95.

Pillai, R.S.N. (1929). A list of fishes taken in Travancore from 1901– 1915. Journal of the Bombay Natural History Society 33(2): 347–379.

Raghavan, R., N. Dahanukar, M. Tlusty, A. Rhyne, K. Krishnakumar, S. Molur & A.M. Rosser (2013). Uncovering an obscure trade: threatened freshwater fishes and the aquarium pet markets. Biological Conservation 164: 158–169; http://dx.doi.org/10.1016/j.biocon.2013.04.019

Ramachandra, T.V., M.D. Subash Chandran, N.V. Joshi, Sreekantha, R. Kumar, R. Rajinikanth, S.R. Desai & S. Babu (2012). Ecological Profile of Sharavathi River Basin., Sahyadri Conservation Series 22, ENVIS Technical Report : 52, November 2012, Energy & Wetlands Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore, India.

River Research Centre (2013). Report on Monitoring of Fish Diversity of Rivers in Kerala. Kerala State Biodiversity Board (KSBB), Thiruvananthapuram, 98pp.

Silas, E.G. (1951). On a collection of fish form the Annamalaiand Nelliampathi Hill ranges (Western Ghats) with notes on its zoogeographical significances. Journal of the Bombay Natural History Society 49: 670–681.

Suter, M. (1944). New records of fish from Poona. Journal of Bombay Natural History Society 44(3): 408-414.

Talwar, P.K. & A.G. Jhingran (1991). Inland Fishes of India and Adjacent Countries - 2 Volumes. Oxford & IBH Publishing Co. New Delhi, 1158pp.

Thomas, R. (2004). Habitat and distribution of hill stream fishes of southern Kerala. PhD Thesis, MahathmaGandhi University, Kottayam, Kerala, India.

Thomas, R.K., M.J. George & C.R. Biju(2002). Freshwater fishes of southern Kerala with notes on the distribution of endemic and endangered species. Journal of the Bombay Natural History Society 99(1): 47–53.

Tonapi, G.T. & L. Mulherkar(1963). Notes on the freshwater fauna of Poona, Part: 1 - Fishes. Proceedings of the Indian Academy of Sciences 58: 187–197; http://dx.doi.org/10.1007/BF03051937

Wagh, G.K. & H.V. Ghate(2003). Freshwater fish fauna of the rivers Mulaand Mutha, Pune, Maharashtra. Zoos’ Print Journal 18(1): 977-981; http://dx.doi.org/10.11609/JoTT.ZPJ.18.1.977-89

Ward, R.D., T.S. Zemlak, B.H. Innes, P.R. Last & P.D. Hebert (2005). DNA barcoding Australia’s fish species. Philosophical Transactions of the Royal Society B: Biological Sciences 360(1462): 1847–1857; http://dx.doi.org/10.1098/rstb.2005.1716

Yang, M., V. Hirt, T. Sado, M. Arunachalam, R. Manickam, K.L. Tang, A.M. Simons, H. Wu, R. Mayden & M. Miya (2012). Phylogenetic placements of the barbin genera Discherodontus, Chagunius, and Hypselobarbus in the subfamily Cyprininae (Teleostei:Cypriniformes) and their relationships with other barbins. Zootaxa 3586: 26–40.