Opsarius barna (HAMILTON, 1822)

SynonymsTop ↑

Cyprinus barna Hamilton, 1822; Barilius barna (Hamilton, 1822); Opsarius fasciatus McClelland, 1839; Opsarius latipinnatus McClelland, 1839; Barilius papillatus Day, 1869: Barilius jayarami Barman, 1985

Etymology

Opsarius: apparently from an Ancient Greek word meaning ‘small fish’.

barna: from a vernacular Bengali name for this species.

Classification

Order: Cypriniformes Family: Cyprinidae

Distribution

Known from the Ganges and Brahmaputra river basins in northern India, and according to current thinking also occurs in the Mahanadi drainage as well as various river systems in Nepal, Bhutan, Bangladesh, and Rhakine State, Myanmar.

Given this distribution existing records from the Mekong drainage appear questionable, though it may occur in the upper part of that system in Yunnan province, China.

Type locality is ‘Yamuna [Ganges] and Brahmaputra rivers, India.’

Habitat

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

At one locality in the Indrawati River basin, Nepal, B. barna was collected from a pristine, fast-to-torrential flowing river with a substrate of cobbles and boulders and a gravel shoreline.

Sympatric species included Botia almorhae, Barilius vagra, B. bendelisis, Schizothoraichthys sp., Schizothorax richardsonii, Tor putitora, Turcinonemacheilus himalaya, Myersglanis blythii, and Pseudecheneis cf. crassicauda.

In the Kamyit Chaung river, Rakhine State, Myanmar, it was collected alongside Rasbora daniconius, R. rasbora, Garra flavatra, G. propulvinus, Aplocheilus panchax, Lepidocephalichthys berdmorei, Batasio elongatus, Awaous personatus and Sicyopterus punctatus plus unidentified Danio, Eleotris, Redigobius, Mastacembelus and Microphis species.

The river is described as ‘moderately large’ and was again very shallow, the fishes being restricted to a series of shallow pools containing clear, slow-moving to stagnant water. The substrate was again a mixture of gravel, pebbles and rocks and no aquatic plants were observed.

Maximum Standard Length

110 – 130 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 Opsarius spp. are prodigious jumpers.

Water Conditions

Temperature: 16 – 24 °C

pH: 6.0 – 8.0

Hardness: 36 – 268 ppm

Diet

Opsarius 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, 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

Adult females are less-brightly-coloured, tend to grow a little larger and are thicker-bodied than males, especially when gravid.

Reproduction

Largely unreported, although spawning can apparently be stimulated by performing large, cool water changes.

NotesTop ↑

This species occasionally appears in the ornamental trade, usually as ‘striped hill trout’ or ‘banded hill trout’.

It can be distinguished from congeners by the following combination of characters: 16 predorsal scales; lateral line complete with 40-42 scales; barbels absent; 10-13 anal-fin rays; body with 9-11 dark blue vertical bars; last dorsal-fin ray extending to caudal-fin base.

The generic placement of species currently referred to Opsarius 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. Conway, K. W., D. R. Edds, J. Shrestha and R. L. Mayden, 2011 - Journal of Fish Biology 79(7): 1746-1759
   A new species of gravel-dwelling loach (Ostariophysi: Nemacheilidae) from the Nepalese Himalayan foothills.
5. Dishma, M. and W. Vishwanath, 2012 - Journal of Threatened Taxa 4(2): 2363-2369
   Barilius profundus, a new cyprinid fish (Teleostei: Cyprinidae) from Koladyne basin, India.
6. 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.
7. 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.
8. 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).
9. Narendran, T. C., P. G. Kumar, and S. I. Kazmi, 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.
10. Selim, K. and W. Vishwanath, 2002 - Journal of the Bombay Natural History Society 99(2): 267-270
    A new cyprinid fish species of Barilius Hamilton from the Chatrickong River, Manipur, India.
11. 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).