Betta sp. "Rukam" from Belitung Island, Indonesia, is a recently documented population showing strong morphological and genetic similarities to Betta uberis, a species originally described from Borneo (Kalimantan). However, genetic analysis using DNA barcoding (COI gene) reveals approximately 94.41% similarity and a genetic distance of 0.057 (33 base differences), indicating it is distinct from true B. uberis. Due to this significant genetic divergence, it is scientifically referred to as Betta cf. uberis, signifying a close but not identical relative. This represents the first confirmed record of a B. uberis-like species outside Borneo, expanding the known distribution of this group. Like B. uberis, it inhabits blackwater peat swamp forests and shares similar care requirements: acidic, soft water, dim lighting, and a diet of small live or frozen foods. It is considered a rare and potentially endangered population.
