TankBud

Chen's lizard loach

Formosania chenyiyui

Also known as Chen's hillstream loach, Mallard hillstream loach

FreshwaterFish

Chen's lizard loach (Formosania chenyiyui)
The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature
61–75°F
16–24°C
pH
6.5–7.5
Adult size
3.6 in
9.2 cm
Minimum tank
25 gal
95 L
Temperament
Mostly peaceful
Social behavior
Social
Swim level
Bottom
Difficulty
Difficult
Breeding
No record
Rarity
Rare
Family
Gastromyzontidae
Origin
Zhejiang and Fujian, southeastern China

Overview

Chen's lizard loach is a slim, active bottom dweller for a cool tank with fast, torrent-grade flow. It is demanding and best left to experienced keepers.

Did you know

The genus name of Chen's lizard loach exists only because of a naming clash. The loaches were first placed in Crossostoma, but that name already belonged to a fossil snail. Formosania was coined in 1919 to take its place.

Caring for the Chen's lizard loach

Give a group of Chen's lizard loaches a tank of 25 gal (95 L) or more, wider than it is tall. It ranges over stone more than it perches, so give it a long, open floor with running room. Add smooth grazing stones, and drive torrent-grade flow with high oxygen.

Keep the water genuinely cool, at 61 to 75°F (16 to 24°C) and a pH of 6.5 to 7.5. Summer heat is the main risk, and a fan or chiller may be needed in a warm room.

Most of its diet is the biofilm and algae it scrapes from rock, so mature the tank first. Then supplement with fine sinking foods, crushed wafers and small frozen items.

Keep it in a small group of five or six. Chen's lizard loach is mostly peaceful and pays little attention to tank mates, though males nudge one another off prime grazing spots. Choose calm, cool-water companions that can hold their own in current without bullying it. Its reproduction has not been recorded in aquaria.

Good to know

Formosania is a group of elongate hillstream loaches in the family Gastromyzontidae. Oshima, who coined the genus name, drew it from Formosa, the historical name for Taiwan. The species itself is named for a Chinese ichthyologist called Chen.

In the wild

Chen's lizard loach lives in cool streams in the coastal ranges of Zhejiang and Fujian, in southeastern China. Rain and runoff keep the water there cold and fast for much of the year.

Weekly picks

Tank mates

The Chen's lizard loach is a mostly peaceful, social species that keeps to the bottom. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a Chen's lizard loach need?

A Chen's lizard loach needs at least 25 gal (95 L). It spends most of its time in the bottom.

What temperature and pH does a Chen's lizard loach need?

A Chen's lizard loach is comfortable at 61–75°F (16–24°C) with a pH of 6.5–7.5.

What does a Chen's lizard loach eat?

A Chen's lizard loach gets most of its diet from the biofilm and algae it scrapes from rock. Supplement it with fine sinking foods, crushed wafers and small frozen items.

How big does a Chen's lizard loach get?

An adult Chen's lizard loach reaches about 3.6 in (9.2 cm).

Related species