Discherodontus halei
SynonymsTop ↑
Barbus halei Duncker, 1904
Etymology
Discherodontus: from the Ancient Greek δίς (dís), meaning ‘twice’, σειρά (seirá), meaning ‘series, line’, and ὀδών (odon), meaning ‘tooth’, since members of this genus possess two rows of pharyngeal teeth which sets them apart from related taxa.
halei: named for Mr. Abrahan Hale, chairman of the Selangor Museum Committee at the time the species was described.
Classification
Order: Cypriniformes Family: Cyprinidae
Distribution
Appears to have a disjunct range with records from Pahang state in central Peninsular Malaysia, plus the Mae Klong and Chao Phraya river systems in Thailand, but it has not been recorded in Peninsular Thailand.
Type locality is ‘Pahang River, Kuala Tembeling, eastern slope of Sangka Dua Pass, Malaysia, elevation about 2000 feet’.
Habitat
Inhabits clear, fast-flowing minor rivers and forest streams. The latter tend to have thick marginal vegetation with dense forest canopy above. There are almost no true aquatic plants but submerged roots and other parts of emergent species are common. Leaf litter and fallen branches tend to accumulate in the stiller zones and this is where the fish are most often found.
Maximum Standard Length
80 – 100 mm.
Aquarium SizeTop ↑
An aquarium with base dimensions of 120 ∗ 45 cm or equivalent should be the smallest considered.
Maintenance
Unreported, but likely to prefer similar conditions to congeners, therefore a set-up designed to resemble a flowing river with a substrate of variably-sized rocks and gravel and some large water-worn boulders is recommended. This can be further furnished with driftwood roots and branches arranged to form some shaded spots.
While the vast majority of plant species will fail to thrive in such surroundings hardy types such as Microsorum, Bolbitis or Anubias can be grown attached to the décor and bright lighting will promote the growth of algae upon which the fish will graze. In this kind of environment it should display more natural behaviour and can be kept alongside some other species that enjoy similar conditions.
Like many fishes that naturally inhabit running water it’s intolerant to the accumulation of organic wastes and requires spotless conditions in order to thrive, meaning weekly water changes of 30-50% tank volume should be considered routine. Though torrent-like conditions are unnecessary it also does best if there is a high level of dissolved oxygen and moderate water movement.
Since it doesn’t cope well with fluctuating water conditions try to acclimatise it to the aquarium over a couple of hours if possible and never introduce it to a biologically immature system.
Water Conditions
Temperature: 21 – 26 °C
pH: 6.0 – 7.5
Hardness: 36 – 215 ppm
Diet
The natural diet of Discherodontus species is comprised largely of aquatic and terrestrial invertebrates.
In the aquarium they should be offered regular meals of live and frozen foods such as chironomid larvae (bloodworm), Daphnia and Artemia along with good quality dried flakes and granules. In a river-style set-up as described above they will often be seen browsing the biofilm that tends to form on the rockwork.
Behaviour and CompatibilityTop ↑
Likely to be peaceful and an ideal resident of the larger, well-furnished community set-up where it will spend most of its time in the lower part of the tank.
It will probably do best when kept alongside other non-aggressive species that require well-oxygenated water. There are plenty of suitable choices including many cyprinids, loaches, catfish and characins although substrate-dwelling cichlids are best omitted unless the tank is very large.
It’s a schooling species by nature and ideally should be maintained in a group of at least half a dozen specimens. Maintaining it in decent numbers will not only make the fish less nervous but will result in a more effective, natural-looking display. Males will also display their best colours as they compete with one other for female attention.
Sexual Dimorphism
Sexually mature females should be noticeably thicker-bodied and a little larger than males.
Reproduction
Unreported.
NotesTop ↑
Discherodontus species are poorly-documented in the hobby, partly as a result of their relatively limited natural ranges but also because most are notoriously delicate and difficult to ship. They tend to lose scales very easily when removed from the water, for example, and should always be transferred to a bag or vessel underwater prior to transport. Areas of the body from which scales have been lost tend to become infected very easily.
The genus was erected by Roberts in 1989 in order to group together a trio of species previously included in the genera Puntius or Acrossocheilus, and has since been expanded to include the Chinese species D. parvus. The primary basis for the separation is that members possess two rows of pharyngeal teeth rather than the three found in almost all other related species.
They’re most closely-related to members of the Indian genera Chagunius and Hypselobarbus and can be further defined by the following combination of characters: vent located relatively anteriorly on body, with additional scale rows between vent and anal-fin; dorsal-spine serrations smal or absent; absence of demarcation between the lower lip and jaw; tips of dorsal-fin and caudal-fin lobes with dark pigmentation.
D. halei can be distinguished from congeners by the following combination of characters: possession of a smooth, spinous dorsal-fin ray; vent located midway between anal-fin and pelvic-fin insertions; orange pigmentation in the dorsal and caudal fins, 9 (vs. 8 in other species) branched pelvic-fin rays; 14 (vs. 16) circumpeduncular scales.
References
- Duncker, G., 1904 - Mitteilungen aus dem Naturhistorischen (Zoologischen) Museum in Hamburg v. 21: 133-207
Die Fische der malayischen Halbinsel. - Kottelat, M., 2013 - The 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. - Rainboth, W. J., 1989 - Occasional Papers of the Museum of Zoology University of Michigan 718: 1-31
Discherodontus, a new genus of cyprinid fishes from southeastern Asia.
