Asian Stone Catfish

Hara jerdoni is a miniature catfish native to fast-flowing, rocky hillstreams in northeastern India and Bangladesh, where it clings to rocks and substrate using its flattened body and pectoral fins adapted to strong current. Its mottled brown and tan coloration provides exceptional camouflage against substrate, rocks, and leaf litter — making it nearly invisible even in the aquarium until it moves.

This species is truly tiny, with adults rarely exceeding 3.5 cm. It belongs to the family Erethistidae, a group of small Asian torrent catfish that are adapted to high-oxygen, fast-moving water. In the aquarium, it prefers cooler temperatures between 15–22°C, making it suitable for unheated or lightly heated tanks in temperate climates, or specialized hillstream setups.

The Asian Stone Catfish is nocturnal and peaceful, spending the day motionless on surfaces and becoming more active after dark. It poses no threat to any tankmate and is actually more vulnerable to being harassed than vice versa. It is best suited to a species-only setup or a quiet nano tank with very small, peaceful companions. Its small size means even tiny invertebrates like dwarf shrimp are safe neighbors. The species is also notable among nano fish enthusiasts for its exceptionally small minimum tank size requirements, making it one of the few catfish appropriate for true nano setups of 20–40 liters. Its preference for cool, flowing water makes it a natural companion for temperate biotope setups featuring White Cloud Minnows, Danio margaritatus, or other cool-water species from similar highland habitats.

Tank Setup A nano tank of 30 liters or larger is sufficient. Strong water flow is critical — use a powerhead or HOB filter creating significant surface agitation. Provide smooth flat rocks, pebbles, and driftwood for the fish to rest on and hide beneath. A sandy substrate with gravel areas works well. Avoid tall, open tanks — focus on surface area and flow.

Water Parameters Maintain pH 6.5–7.5, temperature 15–22°C. This cooler preference distinguishes it from most tropical species. Soft to moderately hard water is preferred. Pristine water quality with very low nitrates is important. Do not keep in warm tropical community tanks.

Feeding Carnivorous, feeding on small invertebrates in nature. Offer micro-sized sinking foods: micro pellets, frozen baby brine shrimp, daphnia, micro worms, and crushed freeze-dried bloodworms. Feed after lights out in small quantities. This species has a tiny mouth and cannot consume standard-sized foods.

Tankmates Best in a species-only nano tank or with equally peaceful, very small fish: Boraras species, Microdevario, Celestial Pearl Danio, or small shrimp. Do not keep with any fish large or active enough to harass it.

Observation Tips Best observed with a red nightlight after main lights go off. Their camouflage is so effective that owners often think they are missing until the fish moves. Count individuals at feeding time to ensure all are present and eating.

Health Notes Sensitive to high temperatures and poor water quality. Avoid heaters that maintain tropical temperatures. Keep ammonia and nitrite at zero at all times.

Long-term Notes Asian Stone Catfish kept in well-maintained cool, flowing nano setups can live 5 or more years. Consistent temperature (never exceeding 22°C for extended periods), clean water, and a steady supply of appropriate live or frozen micro-foods are the key requirements. Patient, observant keepers are rewarded by watching this remarkable miniature fish in the flow of its hillstream biotope.