鲁氏抟鱼

Overview

Correct identification is particularly important for Betta rubra, a small mouthbrooding betta often exported with a similar species. Quiet soft-water housing suits it, but reports of group compatibility vary enough that several pairs should not be assumed to coexist reliably.

Distribution & habitat

Confirmed records come from Singkil in Aceh and around Sibolga in North Sumatra, Indonesia. Although an old locality label mentions Lake Toba, the fish is not thought to inhabit the lake itself. Some earlier records belong to a related species.

One collecting site was a heavily disturbed former peat swamp, drained by artificial channels. Fish occurred in a stagnant blackwater pool but were absent from nearby pools and a river. Regional conflict long limited access, and the species reappeared in the aquarium trade around 2007.

Aquarium setup

A pair requires a footprint of at least approximately 45 × 30 cm; groups need more room. Roots, branches, pots, and pipes create retreats. Leaves provide additional cover and microorganisms useful to fry. Natural peat is unnecessary.

Keep lighting dim, with shade-tolerant or floating plants. Acidic water with very low general hardness and negligible carbonate hardness may require reverse-osmosis preparation. Use gentle filtration, a secure lid, and humid air space above the water.

Diet & feeding

Insects and small invertebrates are likely the main wild foods. Fish usually learn to eat dry preparations, alongside regular live or frozen Daphnia, Artemia, and bloodworms. Newly hatched crickets and fruit flies can be used after feeding them suitable fish food or plant material. Avoid excessive portions.

Behaviour & compatibility

Dedicated housing avoids intimidation and feeding competition from large or active community fish. Accounts of multiple pairs or one-male groups differ. Some keepers observe only limited chasing and territorial disputes, while others find sustained aggression by dominant fish. Be prepared to revert to separate pairs if conflict persists.

Sexual dimorphism

Males show stronger coloration and greater extension of the unpaired fins.

Breeding

A quiet breeding tank with a close-fitting cover preserves warm, moist air for labyrinth development. Courtship and embraces may continue before eggs are produced. Unlike most mouthbrooding bettas, the eggs are initially supported by the female's anal fin; the male collects them directly into his mouth. This repeats until spawning finishes.

Stress or inexperience can lead to swallowing or premature release, so leaving the female undisturbed is generally preferable. After about 10–17 days, the male releases free-swimming young. They can be raised separately or with the adults; some reports describe faster growth alongside the parents.

Offer small, varied meals of microworms and Artemia nauplii two or three times daily, without excessive dependence on Artemia. Maintain regular small water changes.

Notes

Mixed exports with Betta dennisyongi may have led to accidental hybridization. In this species the interrupted stripe behind the eye leaves a complete pale gill-cover edge, while the triangular mark below the eye is narrower. Males also show stronger color with narrower gaps between dark bars. Use these combined features rather than redness alone for identification.