Garra, HAMILTON, 1822

Stiassny, Melanie L. J. & Getahun, Abebe, 2007, 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, Zoological Journal of the Linnean Society 150 (1), pp. 41-83 : 51-52

GARRA HAMILTON, 1822

Type species: Cyprinus (Garra) lamta Hamilton, 1822 by subsequent designation of Bleeker (1863: 192).

Type locality: Behar Province and Rapti River, Gorakhpur District, Uttar Pradesh, India .

Diagnosis: Among cyprinids Garra is phylogenetically diagnosed by the following combination of apomorphic features: lower lip expanded posteriorly to form either an ovoid or circular callous pad or suctorial disc; vomero-palatine organ either vestigial or fully regressed; pectoral fins with the first two or more rays prominent and often unbranched; supraethmoid wider than long in dorsal aspect; cleithrum narrow and anteriorly elongate.

In addition, the following combination of features distinguish Garra from other members of the labeonin subtribe Garraina : pharyngeal teeth in three rows, 2,4,5–5,4,2; dorsal fin with either ten or 11 rays, inserted slightly in advance of pelvic fins; anal fin with either eight or nine rays, situated well behind pelvic fins; diploid chromosome number 50.

Remarks: Garra are generally benthic omnivores, feeding on attached algae, phytoplankton, and small invertebrates. Food is typically scraped off the substrate with sharp, keratinized jaw margins, and then sucked into the mouth by alternating dilation and con- traction of the buccopharynx. Garra have no stomach and the oesophagus leads directly to the intestine, from which it is separated by a sphincter. The length of the intestine varies according to dominant food type, being longer in those species feeding predominantly on plant material. The intestinal length (Int.L) shows marked variation between species and is a useful feature for species identification. Little confirmed sexual dimorphism or dichromatism has been reported. When ripe, more than 75% of the body cavity may be occupied by the gonads. Ripe females carry between 400 and 1000 ovarian eggs (average diameter 1.77 mm; Getahun, 2000). Breeding behaviour is poorly known but spawning migration of lacustrine species to rivers is presumed to occur.

Although African species were poorly represented in Menon’s (1964) revision of Garra , that study provides a useful comparative taxonomic framework and a starting point for further investigation of the genus. Probably in reflection of limited sampling, Menon (1964) recognized only eight species of Garra from the African continent. Not included in that study, or described since, are Garra allostoma Roberts, 1990 , Garra congoensis Poll, 1959 , and Garra lancrenonensis Blache & Miton, 1960 . Getahun (2000), in a taxonomic review of African Garra , resurrected G. aethiopica ( Pellegrin, 1927) , Garra blanfordii ( Boulenger, 1901) , and Garra hindii (Boulenger, 1905) , and synonomized Garra trewavasae Monod, 1950 , and Garra tibanica Trewavas, 1941 , with Garra ornata (Nichols & Griscom, 1917) and Garra quadrimaculata (Ruppell, 1931) , respectively. Including the five new species described herein, we recognize a total of 17 valid African species and an artificial key for their identification is provided here.