Hampala salweenensis DOI & TAKI, 1994

Etymology

Hampala: from a Javanese vernacular name for this genus.

salweenensis: named for the Salween River, to which it is endemic.

Classification

Order: Cypriniformes Family: Cyprinidae

Distribution

Endemic to the River Salween basin although the full extent of its distribution within the watershed is unclear.

Type locality is ‘Mae Surin River, a branch of Mae Pai River, at Ban Huei Phan, Mae Hong Son, northwestern Thailand’.

The Mae Pai is itself a tributary of the Salween that joins the main river channel in the border state of Kayah, Myanmar. It’s also been recorded from the Nam Pang river, another tributary of the Salween located much further north in Shan State, Myanmar.

Habitat

Predominantly a riverine fish preferring clear, well-oxygenated, running water with substrates of sand, gravel, rock or mud although it’s adaptable species and can be found in both upland and lowland, standing or flowing waters.

Maximum Standard Length

The largest officially-recorded specimen measured 200.6 mm.

Aquarium SizeTop ↑

An aquarium with base dimensions of 240 ∗ 60 cm or equivalent should be the smallest considered.

Maintenance

Choice of décor is not as critical as water quality and the amount of open swimming-space provided. However should you possess the means to both provide and decorate a sufficiently-sized aquarium this species a set-up designed to resemble a flowing river with a substrate of variably-sized rocks and gravel, some large water-worn boulders and perhaps a couple of driftwood branches is recommended.

Like many fishes that naturally inhabit running waters it’s 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 level of dissolved oxygen and a decent level of water movement in the tank so external filters, powerheads, etc., should be employed in order to obtain the desired effect.

Be sure to fit the aquarium with a heavy, tightly-fitting cover as larger cyprinids can be quite skittish at times and usually possess a powerful leap.

Water Conditions

Temperature: 20 – 26 °C

pH: 6.0 – 8.0

Hardness: 36 – 357 ppm

Diet

Predatory, and in nature likely to feed on smaller fishes and insects along with a variety of freshwater crustaceans and perhaps some plant material via the stomach contents of prey items.

In the aquarium it will accept dried foods but should not be fed these exclusively with daily meals of live and frozen foods key to keeping it in the best of health.

Smaller specimens can be offered chironomid larvae (bloodworm), small earthworms, chopped prawn and suchlike while adults will take whole prawns, larger earthworms, mussels, whitebait, etc. Take care not to overfeed as it will gorge itself given the opportunity.

It should not be fed large amounts of mammalian/avian meat such as beef heart or chicken. Some of the lipids contained in these meats cannot be properly metabolised by the fish and can cause excess deposits of fat and even organ degeneration. Similarly there is no benefit in the use of ‘feeder’ fish such as livebearers or small goldfish which carry with them associated risks such as the introduction of parasites or disease.

Hampala spp. are voracious feeders especially when maintained in numbers. Some aquarists have observed that the ‘alpha’ individual in a group will lead the others in a pack-style behaviour, and anglers’ reports state that the water surface will literally boil when a shoal is feeding. So enthusiastically does it attack food that it’s sometimes recommended as a useful tankmate for fastidious or newly-introduced fishes that are refusing to eat.

Behaviour and CompatibilityTop ↑

Captures its prey using suction rather than aggressively biting and peaceful with anything it can’t swallow, although its speed of movement and feeding habits suggest that slow-moving or timid tankmates would probably be outcompeted. Similarly-sized cyprinids, characids, catfishes and larger botiid loaches perhaps constitute the best choices.

Though gregarious by nature it’s 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. If only two or three are present the subdominant fish may be subjected to excessive antagonism whereas solitary specimens tend to act rather nervously.

Sexual Dimorphism

Sexually mature females are likely to be thicker-bodied than males.

Reproduction

Unrecorded.

NotesTop ↑

This species is poorly-known in the aquarium hobby.

It can be distinguished from congeners by the following combination of characters: 26-27 lateral line scales; two roundish, dark blotches on each flank, one beneath dorsal-fin origin and above the lateral line, the other on the caudal peduncle and passing through lateral line; upper and lower caudal-fin lobes with black marginal band.

The genus currently contains seven species of which H. macrolepidota and, to a lesser extent, H. dispar are the only ones seen with any regularity in the aquatic trade. As well as being the most widely-distributed H. macrolepidota is also the largest-growing of the group. All representatives can appear superficially similar at first glance, the exception being H. lopezi which is endemic to a single island in The Phillipines and is unique in that it displays a lateral band-like marking on the flanks.

H. macrolepidota is also easy to identify by its colour pattern comprising a dark vertical band originating anterior to the dorsal-fin and extending below the lateral line plus the presence of black marginal stripes in both lobes of the caudal-fin. H. dispar possesses only a single dark blotch-like marking on the body and has less well-defined marginal stripes on the caudal lobes.

Juveniles of the two species can appear very similar as the body blotch is extended vertically in young H. dispar plus both display a broadish dark band across the caudal peduncle, a second, thinner band across the base of the caudal-fin, and a small blotch above the anal-fin. All of these markings are less intense in H. dispar and in H. macrolepidota there is additional dark patterning above and below the eye and running downwards from the nape to the pelvic fins.

H. sabana also has a single body marking but a higher count of circumpeduncular scales (30-32) and relatively few lateral line scales (12-15) compared to its congeners. H. ampalong, H. bimaculata and H. salweenensis can be a little trickier to separate as they all have two body blotches. H. ampalong possesses more lateral line scales than H. salweenensis (28-31 vs. 26-27) whereas in H. bimaculata the body markings are saddle-shaped and the anterior blotch is positioned underneath the posterior half of the dorsal-fin (below the dorsal-fin origin in the other two).

It’s worth noting that the body markings tend to fade in very large specimens of all Hampala spp., and it’s possible that additional species will be described in the future as a phylogenetic study published in 2006 concluded that the form of H. bimaculata from central and southern parts of the Malaysian state of Sarawak, Borneo ought to be considere distinct, for example.

References

1. Doi, A. and Y. Taki, 1994 - Japanese Journal of Ichthyology 40(4): 405–412
   A new cyprinid fish, Hampala salweenensis, from the Mae Pai River system, Salween Basin, Thailand.
2. 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.
3. Ryan, J. R. and Y. B. Esa, 2006 - Zoological Science 23(10): 893-901
   Phylogenetic Analysis of Hampala Fishes (Subfamily Cyprininae) in Malaysia Inferred from Partial Mitochondrial Cytochrome b DNA Sequences.
4. Taki, Y. and A. Kawamoto, 1977 - Japanese Journal of Icthyology 24(1): 61-65
   Differentiation of the Cyprinids, Hampala macrolepidota and H. dispar.