Betta picta  (Spotted Betta)

Distribution

Known only from the island of Java, Indonesia, where it may be endemic to western and central areas.

Type locality is Buitenzorg, Sadingwetang, the former a historic name for the modern city of Bogor, and the latter also appearing to represent a place name.

Habitat

Usually associated with clear, flowing hill streams where it can be found in quiet marginal zones and still pools that typically contain a mixture of leaf litter and rocks. It has also been collected from roadside ditches and artificial structures such as water tanks.

Maximum Standard Length

40 – 50 mm.

Aquarium Size

An  aquarium with base measurements of 60 – 30 cm or equivalent is large enough for a pair or small group.

Maintenance

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 offers additional cover and brings with it the growth of microbe colonies as decomposition occurs. These can provide a valuable secondary food source for fry, while tannins and other chemicals released by the decaying leaves are 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. Aquatic plant species that can survive under such conditions include Microsorum, Taxiphyllum or Cryptocoryne spp., while floating vegetation is also appreciated by the fish.

This species requires acidic conditions with negligible carbonate hardness and very low general hardness, meaning a reverse osmosis unit or other method of obtaining soft water may need to be employed. This can be further acidified using phosphoric acid or similar if necessary.

As it naturally inhabits sluggish waters filtration should 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.

Water Conditions

Temperature: 22 – 28 °C

pH: 5.5 – 7.5

Hardness: 18 – 90 ppm

Diet

Likely to prey on aquatic and terrestrial invertebrates in nature.

Captive fish will normally accept dried products once they are recognised as edible, but should be offered plenty of small live or frozen foods such as Daphnia, Artemia or chironomid larvae (bloodworm) regularly to ensure development of optimal colour and condition.

Take care not to overfeed as Betta spp. seem particularly prone to obesity.

Behaviour and Compatibility

Not recommended for the standard community aquarium. Its care requirements and disposition mean it is best kept alone or with very peaceful species. Some small cyprinids and loaches that inhabit similar environments in nature are suitable, but proper research prior to purchase is essential and in most cases it is best maintained alone.

It is not among the more aggressive members of the genus and can be maintained in a pair or group.

Sexual Dimorphism

Mature males have a broader head shape and are more colourful than females, possessing a greater extent of iridescent scaling on the head, body, and unpaired fins.

Reproduction

Paternal mouthbrooder. Ideally organise a separate aquarium for breeding purposes, unless the fish are already being maintained alone.

The aquarium should have the tightest-fitting cover possible (some breeders use clingfilm/plastic wrap) because the fry need access to a layer of warm, humid air without which development of the labyrinth organ can be impaired.

Following a protracted courtship, eggs and milt are released during an ’embrace’ typical of osphronemids, with the male wrapped around the female. Several ‘dummy’ embraces may be required before spawning commences.

Fertilised eggs are caught on the anal fin of the male then picked up in the mouth of the female before being spat out into the water for the male to catch. Once the male has all the eggs in his mouth the process is repeated until the female is spent of eggs, a process which can take some time.

A brooding male may swallow or release the eggs prematurely if stressed or inexperienced, so it is preferable to leave the female and any other fishes in situ. The incubation period is 9-12 days, after which the male will begin to release free-swimming fry. Apparently the adults do not harm them, and some breeders have reported them to develop at a faster rate when left with the parents.

The fry are large enough to accept motile foods such as microworm and Artemia nauplii immediately, though it should be noted that there exist reports of young Betta developing health issues if fed excessive amounts of the latter. Water changes should be small and regular rather than large and intermittent.

Notes

This species lends its name to the Betta picta complex of closely-related species, an assemblage within which members share the following combination of characters: unpaired fins rounded (anal fin sometimes pointed): I-III, 18-24 anal-fin rays; anal and caudal fins with dark distal margins, most pronounced in mature males; pre- and post-orbital stripes present; chin bar present; opercle with iridescent blue, green, or gold scales.

It can be distinguished from other members of the B. picta group by the following combination of characters: opercle scales iridescent yellow-gold; anal and caudal fins with a narrow, bluish distal band in male; preorbital black stripe relatively narrow; male with faint transverse bars in dorsal-fin and slightly elongated median caudal-fin rays; female with faint transverse bars in caudal-fin.

The genus Betta is the most speciose within the family Osphronemidae. Members have successfully adapted to inhabit a variety of ecological niches from stagnant ditches to flowing hill streams including some extreme environments such as highly acidic peat swamp forests.

The referral of members to a number of groups containing closely-related species is largely based on morphological and behavioural characters.

Like others in the suborder Anabantoidei this species possesses an accessory breathing organ known as the labyrinth, which permits the fish to breathe atmospheric air to a certain extent. Comprising paired suprabranchial organs formed via expansion of the epibranchial (upper) section of the first gill arch and housed in a chamber above the gills, it contains many highly-vascularised, folded flaps of skin which function as a large respiratory surface. Its structure varies in complexity between species, tending to be more developed in those inhabiting harsher environments.

References

1. Cuvier, G. and A. Valenciennes, 1846 – Paris, F.G. Levrault: i-xix + 2 pp. + 1-505 + 2 pp.
   Histoire naturelle des poissons. Tome dix-huitième. Suite du livre dix-huitième. Cyprinoïdes. Livre dix-neuvième. Des Ésoces ou Lucioïdes.
2. Kottelat, M., 1994 – Ichthyological Exploration of Freshwaters 5(4): 297-304
   Diagnoses of two new species of fighting fishes from Thailand and Cambodia (Teleostei: Belontiidae).
3. Linke, H., 2014 – Fish Magazine Taiwan: 1-577
   Labyrinth Fish World.
4. Roberts, T. R., 1993 – Zoologische Verhandelingen (Leiden) 285: 1-94
   The freshwater fishes of Java, as observed by Kuhl and van Hasselt in 1820-23.
5. Schindler, I. and J. Schmidt, 2004 – Zeitschrift für Fischkunde 7(1): 1-4
   Betta pallida spec. nov., a new fighting fish from southern Thailand (Teleostei: Belontiidae).
6. Tan, H. H. and M. Kottelat, 1998 – Revue Suisse de Zoologie 105(3): 557-568
   Redescription of Betta picta (Teleostei: Osphronemidae) and description of B. falx sp. n. from central Sumatra.
7. Tan, H. H. and P. K. L. Ng, 2005 – Raffles Bulletin of Zoology Supplement 13: 115-138
   The labyrinth fishes (Teleostei: Anabanatoidei, Channoidei) of Sumatra, Indonesia.
8. Tan, H. H. and P. K. L. Ng., 2005 – Raffles Bulletin of Zoology Supplement 13: 43-99
   The fighting fishes (Teleostei: Osphronemidae: Genus Betta) of Singapore, Malaysia and Brunei.