单斑抟鱼

Overview

The large paternal mouthbrooder Betta unimaculata varies in pattern and color between localities. Keep collection labels and breeding populations separate, and provide a compatible pair with sheltered, undisturbed accommodation.

Distribution & habitat

It is native to parts of the upper Kayan and Mahakam drainages in East Kalimantan, Indonesian Borneo. Habitats include clear streams, elevated isolated headwater pools, and more turbid forest channels.

Within flowing systems it favors slow pools, while forest populations shelter among bank vegetation, roots, and leaves. Fish formerly identified from Tawau as this species were subsequently described as Betta ocellata.

Aquarium setup

A pair needs at least approximately 80 × 30 cm of floor space. Wood, roots, pots, and tubes create shade and retreats; substrate can be omitted for easier maintenance. Leaves add cover and microorganisms useful as supplementary fry food. Dim light with floating and shade-tolerant plants is appropriate.

Keep filtration gentle. Secure the lid against jumping and retain humid air above the water for breathing.

Diet & feeding

Insects, small invertebrates, and zooplankton are likely natural prey. Dry foods are usually learned, supplemented regularly with live or frozen Daphnia, Artemia, and bloodworms. Large individuals can occasionally receive earthworms. Avoid overfeeding.

Behaviour & compatibility

Dedicated housing is usually preferable to a standard community because large or active fish may intimidate it and outcompete it for food. Companions must be very peaceful and share its needs. Keep a pair for reproduction, or a group only with ample room. Separate locality populations to prevent interbreeding.

Sexual dimorphism

Males are larger and more colorful, with broader heads and longer fin extensions.

Breeding

Natural partner selection from a group is preferable. Arbitrary adult pairs may be incompatible, sometimes fatally; established partners generally coexist well unless cramped. A closely covered breeding tank retains warm, moist air needed by developing fry.

Courtship involves gaping and raised fins and may include several embraces without eggs. Eggs are released in small batches, with both adults collecting them. Those gathered by the female are passed into the male's mouth until he holds the whole brood.

Give him as much quiet as possible afterward, since disturbance increases the risk of swallowing eggs after a few days. Removing the female is a balance between capture disturbance and the possibility that she will harass him or eat fry, particularly in smaller tanks. Incubation takes about 10–14 days. Young have been raised separately, with their father, or with both adults.

Released fry are usually at least about 5 mm and can take microworms and Artemia nauplii. Offer small, varied meals several times daily; overeating readily causes intestinal problems. Daily water changes of around 5–10% help limit organic waste.

Notes

Males have a yellowish-brown body, iridescent gill covers, no dark body bars, and crossbars in the dorsal, anal, and caudal fins. A blunt head is another feature. Check these alongside locality information when separating similar large bettas.