Chinese butterfly loach

Pseudogastromyzon cheni

Also known as Chinese hillstream loach, Chen's hillstream loach, Chinese butterfly hillstream loach

FreshwaterFish

Care at a glance

Temperature: 64–75°F (18–24°C)
pH: 6.5–7.5
Adult size: 2.4 in (6 cm)
Minimum tank: 20 gal (75 L)
Temperament: Mostly peaceful
Social behavior: Social
Swim level: Bottom
Difficulty: Medium
Breeding: Hard
Rarity: Common
Origin: Native to fast, rocky hill streams of Fujian and Zhejiang provinces in southeastern China, in cool, highly oxygenated water.
Family: Gastromyzontidae

Overview

Keep a small group of 4 to 6 in a tank of 75 litres or more with strong flow and smooth rockwork, at 18 to 24 C and pH 6.5 to 7.5. It grazes algae and biofilm, so supplement with vegetable-based sinking foods, blanched vegetables and the occasional frozen treat. Peaceful toward other fish, it suits cool tanks with white cloud minnows, danios and other hillstream loaches.

In the wild

A flattened hillstream loach around 6 cm long that clings to rocks and grazes the algae film. It needs strong current, cool water and high oxygen, the conditions of the shallow rapids it comes from. Smooth stones and a bright light to grow algae give it both grazing surface and the flow it wants. Warm, sluggish water leaves it stressed and prone to wasting away.

Good to know

Its paired fins spread out sideways like small wings and act as a suction pad, letting it hold station on bare rock in strong flow. Males set up small grazing territories on favoured stones and display to each other over them.

Did you know

It is often confused with the larger butterfly hillstream loaches of the genus Beaufortia, but Pseudogastromyzon stays smaller and comes from farther east in China.