All fish / Gastromyzontidae

Sewellia media

Sewellia medius

Also known as sewellia media, sewellia medius, reticulated hillstream loach, butterfly hillstream loach, hillstream loach, gold ring butterfly loach, セウェリア・メディウス, 中华爬岩鳅

No free-to-use photo of this fish yet. Took one yourself? Send it to us and we will credit you.

This is a small, flattened hillstream loach with broad, sucker-like paired fins. Its brown to golden body is covered in dark spots and markings. Keepers like it for its unusual look and the way it grazes over rocks in fast-flowing, cool, well-oxygenated streams.

Care at a glance

Care level

Moderate

Temperament

Peaceful

Adult size

5.5 cm

Temperature

18 to 24 °C

pH

6.5 to 7.5

Smallest tank

80 litres

Keep as

Group of 4 or more

Diet

Omnivore: biofilm and algae, plus sinking pellets, algae wafers and small frozen foods such as bloodworm

Swims

Bottom of the tank

Lifespan

5 to 8 years

Water

Freshwater

Wild range

Central Vietnam (Thu Bon and nearby coastal river drainages)

Breeding

It has spawned in well-matured river-style tanks, where the eggs scatter among gravel and the tiny fry grow up grazing on biofilm. This happens now and then but is hard to plan for.

Good to know

It needs strong flow, plenty of oxygen and cool water, so it does poorly in warm, still tanks. It is often confused with other Sewellia species such as S. lineolata, and males can squabble a little over territory.