Barilius vagra (HAMILTON, 1822)

SynonymsTop ↑

Cyprinus vagra Hamilton, 1822; Opsarius isocheilus McClelland, 1839; Opsarius bicirratus McClelland, 1842; Opsarius piscatorius McClelland, 1842; Barilius alburnus Günther, 1868; Barilius (Pachystomus) bleekeri Day, 1872

Etymology

Barilius: from barila, a vernacular Bengali name for the species B. barila, the type species.

vagra: derived from a vernacular Bengali name for this species.

Classification

Order: Cypriniformes Family: Cyprinidae

Distribution

Widely-distributed in the Ganges and Brahmaputra river systems in northen India, Nepal, and Bangladesh.

It has also been recorded from Afghanistan, Pakistan, and Sri Lanka although these occurrences are in need of clarification and may pertain to other species.

Type locality is ‘Ganges about Patna’ which corresponds to the city of Patna in Bihar state, India.

Habitat

Inhabits well-oxygenated, medium-to-high gradient, moderate to fast-flowing rivers and tributaries with substrates of gravel, cobbles, larger boulders and exposed bedrock.

In the East Rapti River, a tributary draining the Chitwan (inner Terai) valley in Nepal and flowing west to join the Narayani (Gandaki) River close to the Indian border, B. vagra is a perennial resident and occus alongside numerous other species including Neolissochilus hexagonolepis, Pethia conchonius, Puntius sophore, Tor putitora, Barilius barila, B. bendelisis, B. shacra, Garra gotyla, Schizothorax richardsoni, Acanthocobitis botia, Schistura beavani, S. rupecula, Amblyceps mangois, Glyptothorax telchitta, and Mastacembelus armatus.

Maximum Standard Length

100 – 125 mm.

Aquarium SizeTop ↑

Requires a large aquarium with minimum surface area of 150 ∗ 60 cm or equivalent.

Maintenance

The aquarium should ideally be designed to resemble a flowing stream or river with a substrate of variably-sized rocks, sand, fine gravel, and some larger water-worn boulders. This can be further furnished with driftwood roots and branches if you wish but be sure to leave plenty of open swimming space.

While the majority of aquatic plants will fail to thrive in such surroundings hardy genera such as Microsorum, Bolbitis, or Anubias spp. can be grown attached to the décor.

This species is intolerant to the accumulation of organic wastes and requires spotless water at all times in order to thrive. It also does best if there is a high proportion of dissolved oxygen and moderate degree of water movement meaning external filters, powerheads, airstones, etc., should be employed as necessary.

As stable water conditions are obligatory for its well-being this fish should never be added to biologically-immature aquaria, and weekly water changes of 30-50% aquarium volume should be considered mandatory. A tightly-fitting cover is also essential as Barilius spp. are prodigious jumpers.

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Water Conditions

Temperature: 18 – 26 °C

pH: 6.0 – 7.5

Hardness: 36 – 215 ppm

Diet

Barilius spp. are predominantly surface-feeders preying on aquatic and terrestrial insects in nature, with some small fishes and benthic invertebrates probably taken as well.

In the aquarium good quality dried products can be offered but should be supplemented with regular meals of live and frozen fare such as chironomid larvae (bloodworm), Artemia, chopped earthworms, etc. Drosophila fruit flies and small crickets are also suitable provided they are gut-loaded prior to use.

Behaviour and CompatibilityTop ↑

Unsuitable for the general community due to its environmental requirements, and likely to outcompete or intimidate slow-moving and less bold species at meal times since it is an extremely fast swimmer and vigorous feeder. Much smaller fishes should also be omitted as they may be predated upon.

The best tankmates are similarly-sized, robust, pelagic cyprinids such as Dawkinsia, other Barilius or larger Devario and Rasbora spp. while bottom-dwellers could consist of Garra, Crossocheilus, Botia and Schistura spp., for example. Many characids and loricariid catfishes should also work well, but be sure to perform thorough research before purchase.

Although gregarious by nature this is a shoaling rather than schooling species which develops a distinct pecking order and therefore should always be maintained in a group of five or more individuals. If only two or three are purchased the subdominant fish may be bullied incessantly whereas solitary specimens may become aggressive towards similar-looking species.

Sexual Dimorphism

Unconfirmed, but sexually mature females should be heavier-bodied than males when gravid.

Reproduction

Unreported.

NotesTop ↑

This species is poorly-known in the aquarium hobby but is exported on occasion.

It is distinguished from congeners by the following combination of characters: one pair each of maxillary and rostral barbels present; tubercles on head and body poorly-developed; 33-34 lateral line scales; 10-14 vertical bars on each flank that do not extend below the lateral line; dorsal-fin insertion anterior to anal-fin insertion; dorsal and caudal fins with grey distal edges; 21-26 predorsal scales.

The generic placement of Barilius species has been open to question since Howes (1980) concluded that the Barilius grouping, within which they were included at the time, was not monophyletic and identified two separate lineages. The first group contained B. barila, the type species, plus B. bendelisis, B. radiolatus, B. vagra, and B. shacra, while the second included all other species, and initially these were referred to the subdivisions ‘group i’ and ‘group ii’ within Barilius itself.

The composition of these groups is confusing since in a later work Howes (1983) included B. evezardi and B. modestus in ‘group i’ whilst omitting B. bendelisis, B. radiolatus, and B. shacra without explicitly stating why.

Rainboth (1991) assigned the members of Howe’s ‘group ii’ to the revalidated generic name Opsarius based on the fact it was the oldest available with ‘group i’ species retaining the name Barilius due to the presence of the type species.

This system has been followed by some subsequent authors, e.g., Tang et al. (2010) and Collins et al. (2012) but not gain wider usage until Kottelat (2013), who included all former Barilius from Southeast Asia in Opsarius.

References

1. Hamilton, F., 1822 - Edinburgh & London: i-vii + 1-405
   An account of the fishes found in the river Ganges and its branches.
2. Arunkumar, L. and H. Tombi Singh, 2000 - Journal of the Bombay Natural History Society 97(2): 247-252
   Bariliine fishes of Manipur, India, with description of a new species: Barilius lairokensis.
3. Collins R. A., K. F. Armstrong, R. Meier, Y. Yi, S. D. J. Brown, R. H. Cruickshank, S. Keeling, and C. Johnston, 2012 - PLoS ONE 7(1): e28381
   Barcoding and border biosecurity: identifying cyprinid fishes in the aquarium trade.
4. Howes, G. J., 1980 - Bulletin of the British Museum (Natural History) : Zoology series 37(3): 129-198
   The anatomy, phylogeny and classification of bariliine cyprinid fishes.
5. Kottelat, M., 2013 - Raffles Bulletin of Zoology Supplement 27: 1-663
   The fishes of the inland waters of southeast Asia: a catalogue and core bibiography of the fishes known to occur in freshwaters, mangroves and estuaries.
6. Liao, T.-Y., S. O. Kullander, and F. Fang, 2011 - Journal of Zoological Systematics and Evolutionary Research 49(3): 224-232
   Phylogenetic position of rasborin cyprinids and monophyly of major lineages among the Danioninae, based on morphological characters (Cypriniformes: Cyprinidae).
7. Nath, P., D. Dam, and A. Kumar, 2010 - Records of the Zoological Survey of India 110(3): 19-33
   A New Fish Species of the Genus Barilius (Cyprinidae: Rasborinae) from River Siang, D'Ering Memorial Wildlife Sanctuary, Arunachal Pradesh, India.
8. Tang, K. L., M. K. Agnew, W. J. Chen., M. V. Hirt, T. Sado, L. M. Schneider, J. Freyhof, Z. Sulaiman, E. Swartz, C. Vidthayanon, M. Miya, K. Saitoh, A. M. Simons, R. M. Wood, and R. L. Mayden, 2010 - Molecular Phylogenetics and Evolution 57(1): 189-214
   Systematics of the subfamily Danioninae (Teleostei: Cypriniformes: Cyprinidae).