Pethia phutunio (HAMILTON, 1822)

Dwarf Barb

SynonymsTop ↑

Cyprinus phutunio Hamilton, 1822; Barbus phutunio (Hamilton, 1822); Puntius phutunio (Hamilton, 1822); Systomus leptosomus McClelland, 1839

Etymology

Pethia: the generic vernacular name for small cyprinids in the Sinhala language.

phutunio: appears to follow a local vernacular name for the fish.

Classification

Order: Cypriniformes Family: Cyprinidae

Distribution

Described from ‘ponds of northeastern Bengal’ which according to changes in the region should now refer to Bangladesh or possibly the extreme north of West Bengal state, India, and appears endemic to the lower Ganges and Brahmaputra river basins in Bangladesh plus the Indian states of Bihar, West Bengal, Orissa, Assam, and Tripura.

Records from Myanmar are now considered to represent Pethia didi (Kullander and Fang, 2005) whilst occurrences in Pakistan and Nepal would also appear to be cases of misidentification.

Habitat

Inhabits sluggish rivers, streams, ponds and swamps which are often choked with algae or aquatic plants at certain times of year.

It’s often associated with deep substrates of mud or silt.

Maximum Standard Length

25 – 30 mm.

Aquarium SizeTop ↑

Base dimensions of at least 60 ∗ 30 cm or equivalent are required.

Maintenance

Choice of décor is not especially critical though it tends to show better colouration in a heavily-planted set-up with a dark substrate.

The addition of some floating plants and driftwood roots or branches to diffuse the light entering the tank also seems to be appreciated and adds a more natural feel.

Filtration does not need to be particularly strong though it does seem to appreciate a degree of water movement and will also do well in a hill stream-type set-up.

Water Conditions

Temperature: 21 – 26 °C

pH: 6.0 – 7.0

Hardness: 54 – 215 ppm

Diet

Primarily a micropredator feeding on small insects, worms, crustaceans and other zooplankton in nature.

In the aquarium it will accept dried foods of a suitable size but should not be fed these exclusively.

Daily meals of small live and frozen fare such as Daphnia, Artemia and suchlike will result in the best colouration and encourage the fish to come into breeding condition.

Behaviour and CompatibilityTop ↑

Very peaceful but does not make an ideal community fish due to its small size and rather timid nature.

It will do best when maintained alone or with other diminutive species such as Microdevario, Trigonostigma, smaller Danio, Lepidocephalichthys, and freshwater shrimp of the genera Caridina and Neocaridina.

It’s a schooling species by nature and really should be kept in a group of at least 8-10 specimens.

Maintaining it in decent numbers will not only make the fish less nervous but result in a more effective, natural-looking display, plus males will also display their best colours and some interesting behaviour as they compete with one other for female attention.

Sexual Dimorphism

Adult males tend to be noticeably slimmer than females and possess more intense colour pattern.

The ventral fins are reddish in males, yellow in females.

Reproduction

Possibly unrecorded, but recommendations for related species are as follows:

Like most small cyprinids Pethia  spp. are egg-scattering free spawners exhibiting no parental care.

When in good condition they will spawn often and in a mature aquarium it’s possible that small numbers of fry may start to appear without intervention.

However if you want to maximise yield a more controlled approach is required.

The adult group can still be conditioned together but a smaller aquarium should also be set up and filled with mature water.

This should be very dimly lit and the base covered with some kind of mesh of a large enough grade so that the eggs can fall through but small enough so that the adults cannot reach them. The widely available plastic ‘grass’-type matting can also be used and works well, as does a layer of glass marbles.

Alternatively filling much of the tank with a fine-leaved plant such as Taxiphyllum spp. or spawning mops can also return decent results.

The water itself should be of slightly acidic to neutral pH with a temperature towards the upper end of the range suggested above, and an air-powered sponge filter or air stone(s) should also be included to provide oxygenation and water movement.

When the adults are well-conditioned and the females appear gravid one or two pairs should then be introduced, and spawning should take place the following morning.

An alternative is to spawn the fish in a group with half a dozen specimens of each sex being a good number, although a larger aquarium may be necessary.

In either situation the adults will probably eat the eggs given the chance and should be removed as soon as any are noticed.

These should hatch in 24-36 hours with the fry free swimming after 3-4 days.

They should be fed on an infusoria-grade food for the first few days until large enough to accept microworm, Artemia nauplii, or suchlike.

NotesTop ↑

This frequently misidentified species is sometimes referred to as  ‘spotted-sail barb‘ or ‘spotted-tail barb’ and is quite rare in the aquarium trade.

It was formerly included in the Puntius conchonius ‘group’ of closely-related species alongside P. ater, P. bandula, P. conchonius, P. cumingii, P. didi, P. erythromycter, P. gelius, P. khugae, P. macrogramma, P. manipurensis, P. meingangbii, P. nankyweensis, P. nigripinnis, P. nigrofasciatus, P. padamya, P. punctatus, P. reval, P. shalynius, P. stoliczkanus, P. thelys, P. tiantian, and P. ticto, but all of these were moved to the new genus Pethia by Pethiyagoda et al. (2012), as were P. melanomaculata, P. pookodensis, P. muvattupuzhaensis, P. ornatus, and P. yuensis.

‘Puntius‘ narayani was not moved to the new genus and is currently of uncertain generic placement since it uniquely possesses 9 branched dorsal-fin rays and 6 branched anal-fin rays.

Pethia species are defined by the following combination of characters:  rostral barbels absent; maxillary barbels minute or absent; possession of a stiff, serrated last unbranched dorsal-fin ray; presence of a black blotch on the caudal peduncle, and frequently, black blotches, spots or bars on the side of the body; infraorbital 3 deep and partially overlapping the preoperculum.

In P. phutonio the flank markings comprise two black, vertically-orientated blotches, one posterior to the operculum and the other on the caudal peduncle, and within the genus this patterning is shared with P. bandula, P. cumingii, P. didi, P. meingangbii, P. padamya, and P. tiantian.

It can be told apart from these by the following combination of characters: smaller adult size of 25 – 30 mm vs. at least 35 – 40 mm; minute maxillary barbels; incomplete lateral line with about 5 perforated scales; last dorsal-fin ray osseous and serrated proximally; 4 gill rakers; 10 circumpeduncular scales.

It also has a total of 4 dark markings on each flank with humeral and caudal peduncle blotches plus a small dark blotch at the anterior dorsal-fin base and a lighter-coloured bar extending extending from the posterior dorsal-fin base to around midbody.

The latter can vary in length between individuals and is sometimes absent entirely, however.

The genus Puntius was viewed as a polyphyletic catch-all containing over 100 species of small to mid-sized cyprinid for a number of years until Pethiyagoda et al. (2012) published a partial review covering South Asian members.

The majority of sub-Himalayan Puntius species were reclassified and new genera Dawkinsia, Dravidia, and Pethia erected to accomodate some of them, with the remainder either retained in Puntius or moved to the existing Systomus assemblage, though the definition of the latter was altered meaning some Southeast Asian species formerly placed there are no longer members.

It subsequently became clear that the name Dravidia was preoccupied by a genus of flesh fly, therefore the replacement name Haludaria was made available by Pethiyagoda (2013).

No species from Indochina, China, or Indonesia were included in the study meaning a significant number of former Puntius are currently classed as incertae sedis, i.e., of uncertain taxonomic placement, and this also applies to a number of South Asian species of unresolved status.

They’re perhaps best referred to as ‘Puntius‘ for the time being whereby the genus name is surrounded by quotation marks to denote its questionable usage, and that is the convention used here on SF at the moment.

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. T. Tombi Singh, 2003 - Journal of the Bombay Natural History Society 99(3): 481-487
   Two new species of puntiid fish from the Yu River system of Manipur.
3. Knight, J. D. M., K. Rema Devi, T. J. Indra and M. Arunachalam, 2012 - Journal of Threatened Taxa 4(3): 2409-2416
   A new species of barb Puntius nigripinnis (Teleostei: Cyprinidae) from southern Western Ghats, India.
4. Kullander, S. O., 2008 - Ichthyological Exploration of Freshwaters 19(1): 59-84
   Five new species of Puntius from Myanmar (Teleostei: Cyprinidae).
5. Kullander, S. O. and F. Fang, 2005 - Copeia 2005(2): 290-302
   Two new species of Puntius from northern Myanmar (Teleostei: Cyprinidae).
6. Kullander, S. O. and R. Britz, 2008 - Electronic Journal of Ichthyology, Bulletin of the European Ichthyology Society: 56-66
   Puntius padamya, a new species of cyprinid fish from Myanmar (Teleostei: Cyprinidae).
7. Menon, A. G. K., K. Rema Devi, and W. Vishwanath, 2000 - Journal of the Bombay Natural History Society 97(2): 263-268
   A new species of Puntius (Cyprinidae: Cyprininae) from Manipur, India.
8. Pethiyagoda, R., 2013 - Zootaxa 3646(2): 199
   Haludaria, a replacement generic name for Dravidia (Teleostei: Cyprinidae).
9. Pethiyagoda, R., M. Meegaskumbura, and K. Maduwage, 2012 - Ichthyological Exploration of Freshwaters 23(1): 69-95
   A synopsis of the South Asian fishes referred to Puntius (Pisces: Cyprinidae).
10. Vishwanath, W. and J. Laisram, 2004 - Journal of the Bombay Natural History Society 101(1): 130-137
    Two new species of Puntius Hamilton-Buchanan (Cypriniformes: Cyprinidae) from Manipur, India, with an account of Puntius species from the state.