Betta albimarginata

<em>Betta albimarginata</em>, commonly known as the strawberry betta or white-seam fighter, is a diminutive freshwater fish belonging to the family Osphronemidae. Native to the island of Borneo, specifically from the Malinau region of East Kalimantan, Indonesia, this species inhabits slow-moving, often blackwater streams and forest pools characterised by soft, acidic water and heavy leaf litter. It reaches a maximum recorded length of approximately 2.77 cm, ranking it among the smallest members of the genus <em>Betta</em>. Details of precise habitat extent and geographic range beyond the Malinau region remain limited in the ichthyological literature. This species is a paternal mouthbrooder, with the male carrying eggs and larvae in his mouth until the fry are ready to be released — a fascinating reproductive strategy highly prized by aquarists specialising in wild-type bettas. For aquarium keeping, <em>B. albimarginata</em> thrives in a heavily planted nano tank or species-specific setup with soft, acidic water (pH 4.5–6.5), subdued lighting, and an abundance of dried leaf litter to mimic its natural habitat. Temperatures of 22–26 °C are appropriate. Due to its small size, tank mates should be chosen with extreme care. This species is considered vulnerable to habitat loss in Borneo due to deforestation and peat-swamp drainage.