A free field guide to Borneo's freshwater fish — 82 species, from the giant, endangered Asian Arowana to river bettas, blackwater rasboras and armoured catfish, each with photographs and identification notes. 60 of the 82 have a confirmed, properly licensed photograph so far; the rest are still awaiting one. Nothing to buy and nothing to sign up for.
What this list covers
Borneo's rivers, blackwater swamps and flooded forest streams hold one of the richest freshwater fish faunas in Southeast Asia — cross-checked where possible against the Sabah Forestry Department's 2021 "Inland Fishes of Sabah" survey, which recorded 100 species and marked 42 of them as Bornean endemics. This guide spans everything from the prized, heavily-trafficked Asian Arowana to small blackwater specialists like the Bornean-endemic bettas and rasboras that rarely turn up outside a specialist aquarium collection.
Where a species-specific fact isn't confirmed, the write-ups lean on genus-level natural history — several of Borneo's smaller river and blackwater fish are little-documented outside specialist ichthyological literature.
Where to find them
Most species here are river and stream fish rather than lake dwellers — clear-water hillstream stretches for loaches and hillstream loaches, blackwater swamp forest for bettas and rasboras, and larger lowland rivers for arowana, mahseer and the bigger catfish and snakehead species. A few, like mudskippers, are found in mangrove and estuarine habitat rather than pure freshwater. Sport and subsistence anglers, snorkellers in clear hillstream pools, and guided river trips are the most reliable ways to encounter them.
All 82 species
Each card has two colour-coded toggles:
turns lime green — adds it to your trip planner
turns blue — marks it as seen in my sightings
