Bengkayang, a region in West Kalimantan, Indonesia, hosts freshwater habitats that remain exceptionally well preserved, and in the fast-flowing upper stretches of these rivers, a wonderful family of highly adapted fish species can be found. Much like lichens can be a biological indicator of air quality, or earthworms an indicator of soil health, the Gastromyzontidae family of fishes found in Bengkayang comprise species that are often used as bioindicators of river health due to their sensitivity to subtle changes in their underwater biotopes. Species from the Gastromyzon and Hypergastromyzon genera known as the Borneo suckers or hill stream loaches are …
