The genus was established by Francis Buchanan-Hamilton in 1822 as a subgenus of Cyprinus (which at that time was a "basket genus" for carp-like cyprinids); though it didn't lead to an act of him to designate a type species by the time. However, as no other garras except the newly discovered G. lamta were known to science in 1822, this was designated as the type species by Pieter Bleeker in 1863. The garras and their closest relatives are sometimes placed in a subfamily Garrinae, but this seems hardly warranted. More often, this group is included in the Labeoninae, or together with these in the Cyprininae. In the former case, the garras are members of the labeonine tribeGarrini, in the latter they are in the subtribeGarraina of tribe Labeonini. The genus Discogobio is a close relative.[3]
These species are slim cyprinids with a flat belly and a sucking mouth; their shape indicates that they are at least in tendency rheophilic. They are distinguished from other cyprinids by a combination of features: As in their closest relatives, their lower lip is expanded at its posterior rim to form a round or oval sucking pad, the vomero-palatine organ is much reduced or completely lost, the pectoral fins have at least the first two rays enlarged and usually unbranched, the supraethmoid is wider than long when seen from above, and the cleithrum is narrow and elongated to the front.[3]
From other Garrini (or Garraina), the genus Garra can be distinguished as follows: their pharyngeal teeth are arranged in three rows (like 2,4,5–5,4,2), the dorsal fin has 10-11 rays and starts slightly anterior to the pelvic fins, while the anal fin starts well behind the pelvic fins and has 8-9 rays. As far as is known, the diploidkaryotype of garras is 2n = 50.[3]
When the females are ready to spawn, they are markedly plump and swollen; the ripe roe may fill almost four-fifths of their body cavity. The testicles of reproductive males are large too. The average Garra egg is 1.77 mm in diameter and a clutch contains several hundred eggs – up to a thousand or so in large females. The breeding behaviour is generally not well known and breeding is not often achieved in the aquarium; presumably, like many of their relatives they migrate upstream or (if they otherwise inhabit lakes) into the rivers to spawn.[3]
^ abMousavi-Sabet, H. & Eagderi, S. (2016): Garra lorestanensis, a new cave fish from the Tigris River drainage with remarks on the subterranean fishes in Iran (Teleostei: Cyprinidae). FishTaxa, 1 (1): 45-54.
^ abFarashi, A., Kaboli, M., Rezaei, H.R., Naghavi, M.R., Rahimian, H. & Coad, B.W. (2014): Reassessment of the taxonomic position of Iranocypris typhlops Bruun & Kaiser, 1944 (Actinopterygii, Cyprinidae). ZooKeys, 374: 69-77.
^Romero, A., editor (2001). The Biology of Hypogean Fishes, p. 17. Developments in Environmental Biology of Fishes. ISBN978-1402000768
^ abMOUSAVI-SABET, Hamed, et al. “Tashan Cave a New Cave Fish Locality for Iran; and Garra Tashanensis, a New Blind Species from the Tigris River Drainage (Teleostei: Cyprinidae).” FISHTAXA(2016) 1(3): 133-148, http://www.fishtaxa.com/index.php/ft/article/view/1-3-3.
^ abcdArunachalam, M., Nandagopal, S. & Mayden, R.L. (2013): Morphological diagnoses of Garra (Cypriniformes: Cyprinidae) from North-Eastern India with four new species description from Brahmaputra River. Journal of Fisheries and Aquaculture, 4 (3): 121-138.
^Esmaeili, H.R., Sayyadzadeh, G., Coad, B.W. & Eagderi, S. (2016): Review of the genus Garra Hamilton, 1822 in Iran with description of a new species: a morpho-molecular approach (Teleostei: Cyprinidae). Iranian Journal of Ichthyology, 3 (2): 82-121.
^ abcNebeshwar, K. & Vishwanath, W. (2013): Three new species of Garra (Pisces: Cyprinidae) from north-eastern India and redescription of G. gotyla. Ichthyological Exploration of Freshwaters, 24 (2): 97-120.
^ abThoni, R.J., Gurung, D.B. & Mayden, R.L. (2016): A review of the genus Garra Hamilton 1822 of Bhutan, including the descriptions of two new species and three additional records (Cypriniformes: Cyprinidae). Zootaxa, 4169 (1): 115-132.
^ abNebeshwar, K. & Vishwanath, W. (2015): Two new species of Garra (Pisces: Cyprinidae) from the Chindwin River basin in Manipur, India, with notes on some nominal Garra species of the Himalayan foothills. Ichthyological Exploration of Freshwaters, 25 (4): 305-321.
^ abShangningam, B. & Vishwanath, W. (2015): Two new species of Garra from the Chindwin basin, India (Teleostei: Cyprinidae). Ichthyological Exploration of Freshwaters, 26 (3): 263–272.
^ abLothongkham, A., Arbsuwan, S. & Musikasinthorn, P. (2014): Garra waensis, a new cyprinid fish (Actinopterygii: Cypriniformes) from the Nan River basin of the Chao Phraya River system, northern Thailand. Zootaxa, 3790 (4): 543–554.
^ abcdBehrens-Chapuis, S., Herder, F., Esmaeili, H.R., Freyhof, J., Hamidan, N.A., Özuluğ, M., Šanda, R. & Geiger, M.F. (2015): Adding nuclear rhodopsin data where mitochondrial COI indicates discrepancies – can this marker help to explain conflicts in cyprinids? DNA Barcodes, 3 (1): 187-199.
^Freyhof, J. (2016): Redescription of Garra elegans (Günther, 1868), a poorly known species from the Tigris River drainage (Teleostei: Cyprinidae). Zootaxa, 4173 (5): 496-500.
^ abcGurumayum, S.D. & Kosygin, L. (2016): Garra tamangi, a new species of cyprinid fish (Teleostei: Cypriniformes) from Arunachal Pradesh, northeastern India. Species, 17 (55): 84-93.
^ abKurup, B.M. & Radhakrishnan, K.V. (2011): Two new cyprinid fishes under the genus Garra (Hamilton) from Kerala, southern India. Journal of the Bombay Natural History Society, 107 (3): 220-223.
^ abcHamidan, N.A., Geiger, M.F. & Freyhof, J. (2014): Garra jordanica, a new species from the Dead Sea basin with remarks on the relationship of G. ghorensis, G. tibanica and G. rufa (Teleostei: Cyprinidae). Ichthyological Exploration of Freshwaters, 25 (3): 223-236.
^Kangrang, P., Thoni, R.J., Mayden, R.L. & Beamish, F.W.H. (2016): Garra fluviatilis, a new hillstream fish species (Cypriniformes: Cyprinidae) from the Kwai Noi River system, Mae Khlong basin, Thailand. Zootaxa, 4175 (4): 335-344.
^Zheng, L.-P., Yang, J.-X. & Chen, X.-Y. (2016): Garra incisorbis, a new species of labeonine from Pearl River basin in Guangxi, China (Teleostei: Cyprinidae). Ichthyological Exploration of Freshwaters, 26 (4): 299-304.
^ abcArunachalam, M. & Nandagopal, S. (2014): A New Species of the Genus Garra Hamilton, (Cypriniformes: Cyprinidae) from Nethravathi River, Western Ghats, India. Species, 10 (24): 43-57.
^ abArunachalam, M., Nandagopal, S. & Mayden, R.L. (2014): Two new Species of Garra from Mizoram, India (Cypriniformes: Cyprinidae) and a General Comparative Analyses of Indian Garra. Species, 10 (24): 58-78.
^Yu, Q., Wang, X., Xiong, H. & He, S. (2016): Garra longchuanensis, a new cyprinid (Teleostei: Cypriniformes) from southern China. Zootaxa, 4126 (2): 295-300.
^Tamang, L. (2013): Garra magnidiscus, a new species of cyprinid fish (Teleostei: Cypriniformes) from Arunachal Pradesh, northeastern India. Ichthyological Exploration of Freshwaters, 24 (1): 31-40.
^Sayyadzadeh, G., Esmaeili, H.R. & Freyhof, J. (2015): Garra mondica, a new species from the Mond River drainage with remarks on the genus Garra from the Persian Gulf basin in Iran (Teleostei: Cyprinidae). Zootaxa, 4048 (1): 75–89.
^Shangningam, B. & Vishwanath, W. (2012): A New Species of the Genus Garra Hamilton, 1822 from the Chindwin Basin of Manipur, India (Teleostei: Cyprinidae: Labeoninae). International Scholarly Research Network (ISRN Zoology), 2012: 1-6.
^Shangningam, B. & Vishwanath, W. (2012): Validation of Garra namyaensis Shangningam & Vishwanath, 2012 (Teleostei: Cyprinidae: Labeoninae). Ichthyological Exploration of Freshwaters, 23 (1): 10-10.
^Tangjitjaroen, Z. S. Randall, Tongnunui, Boyd & Page Species of Garra (Cyprinidae: Labeoninae) in the Salween River basin with description of an enigmatic new species from the Ataran River drainage of Thailand and Myanmar, Zootaxa 5311 (3): 375–39.
^Thoni, R.J. & Mayden, R.L. (2015): Garra robertsi, a new cyprinid (Cypriniformes: Cyprinidae) fish species from Borneo. Zootaxa, 3985 (2): 284–290.
^Lyon, R.G., Geiger, M.F. & Freyhof, J. (2016): Garra sindhi, a new species from the Jebel Samhan Nature Reserve in Oman (Teleostei: Cyprinidae). Zootaxa, 4154 (1): 79-88.