Betta albimarginata Care Guide - Habitat, Diet & Breeding

Betta albimarginata is a small and striking wild betta, often known as the white-seam fighting fish. Its body is typically deep reddish brown to coppery, with contrasting dark fins edged by a narrow white margin. The delicate fin edging becomes especially noticeable when the fish is displaying or courting.

Betta albimarginata is native to the Sebuku River drainage in East Kalimantan, on the Indonesian part of the island of Borneo. It inhabits shallow, slow-moving blackwater streams and forested swamp environments.

A pair can be housed in an established aquarium of at least 30 litres, while a small group benefits from around 60 litres or more. A footprint of approximately 45 × 30 cm is a useful minimum for a pair, with extra floor space preferred for groups. Use a secure lid, gentle filtration and subdued lighting, together with dense plants, floating cover, leaf litter, smooth wood and other visual barriers. Fine sand or another soft, inert substrate suits the species, while botanicals can provide shelter and help recreate its tannin-rich forest-stream habitat.

Adults reach a maximum of about 5 cm (2 in) in total length. Females are often slightly larger and fuller-bodied than males, while males are usually more vividly coloured.

This species is primarily a small carnivore and naturally feeds on aquatic insects, insect larvae, tiny crustaceans and other small invertebrates. Offer a varied diet of appropriately sized frozen or live foods such as daphnia, mosquito larvae, brine shrimp and bloodworm. High-quality small betta or micropellet foods can supplement the diet, but live and frozen foods are particularly useful for maintaining condition and encouraging breeding.

Betta albimarginata is relatively peaceful for a betta, but it is best kept in a species-focused aquarium or with calm, similarly sized blackwater fish. Small Boraras rasboras, peaceful small tetras, pencilfish and freshwater shrimp may work in a spacious, carefully planned community, although very small shrimp can be eaten. Avoid fin-nipping species, boisterous tankmates, large predatory fish and other similarly shaped male bettas. Males may defend small territories, particularly around breeding sites.

Betta albimarginata are paternal mouthbrooders. After courtship and spawning, the male gathers the eggs and holds them in his mouth for roughly 10 to 14 days, depending on temperature. He should be left undisturbed during this period, as stress may cause him to swallow or release the brood. Once the free-swimming fry emerge, they can be offered very small live foods such as infusoria and newly hatched brine shrimp. Removing the female or separating the male after spawning can help protect the young.

Males are generally slimmer and show stronger red, copper and dark colouration, with more pronounced white edging on the fins. Females are usually larger-bodied and less intensely coloured, with a rounder abdomen, especially when carrying eggs.