dennisyongi: named for Dennis Yong Ghong Chong ‘a distinguished and knowledgeable naturalist well experienced in many facets of tropical Southeast Asian fauna and flora with an avid interest in labyrinth fishes’.
Currently known only from the western coast of central Aceh province, northwestern Sumatra, Indonesia, between the city of Meulaboh and lowland hill streams north of the town of Singkil.
Type locality is ‘Sumatra: Aceh: Kabupaten Nagan Raya: Lamie, Alue Rayeuk, stream along road Meulaboh-Blangpidie’.
Some former localities for the congener B. rubra are currently considered to refer to B. dennisyongi and it’s unclear if the two occur together naturally in some locations due to human interference (Tan, 2013).
Has been collected from lowland hillstreams and acidic freshwater swamps containing clear to brownish water.
One hill stream habitat contained relatively fast flowing clear water with a pH of 7.0), a sandy substrate and steep clay banks, with the fish collected among submerged leaf litter.
The type series was collected from submerged leaf litter and marginal vegetation in slowly-moving brown water with a pH of 6.0 and a substrate of mud and clay.
Syntopic fish species include Osteochilus jeruk,Rasbora jacobsoni,R. kluetensis, Nemacheilus tuberigum,Mystus punctifer, Ompok brevirictusandKryptopterus piperatus(Tan, 2013).
Maximum Standard Length
30 – 35.5 mm.
An aquarium with base measurements of45 ∗ 30cmor equivalent is sufficient for a single pair, with something larger required for a group.
Can be maintained in a fully-decorated aquarium although many breeders prefer not to use a substrate for ease of maintenance.
Driftwood roots and branches can be used and placed such a way that a few shady spots are formed while clay plant pots or lengths of piping can also be included to provide further shelter.
The addition of dried leaf litter further emphasises the natural feel and as well as offering additional cover for the fish brings with it the growth of microbe colonies as decomposition occurs.
These can provide a valuable secondary food source for fry and the tannins and other chemicals released by the decaying leaves are also considered beneficial for fishes from blackwater environments.
There is no need to use natural peat, however, the collection of which is both unsustainable and environmentally-destructive.
Like others in the genus this species seems to do best under fairly dim lighting.
You could add aquatic plant species that can survive under such conditions such asMicrosorum,TaxiphyllumorCryptocorynespp., and a few patches of floating vegetation would be useful as well.
This species should ideally be kept in conditions with negligible carbonate hardness and very low general hardness so a reverse osmosis unit or other method of obtaining soft water may need to be employed, and this can be further acidified using phosphoric acid or similar if necessary.
Filtration need not be too strong, with an air-powered sponge filter set to turn over gently adequate.
Keep the tank well-covered and do not fill it to the top as like all Betta spp. it requires occasional access to the layer of humid air that will form above the water surface, and is an excellent jumper.
Temperature: 22 – 27 °C
pH: 5.0 – 7.0
Hardness: 18 – 90 ppm
Likely to feed mostly on insects and other small invertebrates in nature.
Captive fish will normally accept dried products once they’re recognised as edible, but should be offered plenty of small live or frozen foods such as Daphnia, Artemia or bloodworm regularly to ensure development of optimal colour and condition.
Small insects such as newly-hatched crickets or Drosophila fruit flies are also suitable to use; it’s best to fill the stomachs of these by feeding them fish flakes or some kind of vegetable matter before offering them to the fish.
Take care not to overfeed as Betta spp. seem particularly prone to obesity.
Males are more colourful and develop more-extended unpaired fins than females.