Butterfly loach
Beaufortia kweichowensis
Also known as Butterfly hillstream loach
FreshwaterFish
Care at a glance
- Temperature
- 61–75°F
- 16–24°C
- pH
- 6.0–7.5
- Adult size
- 3 in
- 7.5 cm
- Minimum tank
- 25 gal
- 95 L
- Temperament
- Peaceful
- Social behavior
- Social
- Swim level
- Bottom
- Difficulty
- Medium
- Breeding
- No record
- Rarity
- Rare
- Family
- Gastromyzontidae
- Origin
- China
Overview
The butterfly loach, sometimes sold as the butterfly hillstream loach, is a broad, flat grazer that fans its patterned fins out against rocks and glass. It is social and calm, so keep several together, around five or more, and give them open hard surfaces to work across. They spend the day rasping biofilm and algae, which should be supplemented with sinking wafers, blanched courgette, and small frozen foods once a film builds up. Pair them with peaceful, cool-water fish that share their need for current. A group needs an oxygen-rich tank of about 95 liters or larger with strong, steady flow.
In the wild
Beaufortia kweichowensis comes from fast, rocky rivers in southern China, where it clings to stones in shallow, sunlit runs. These are subtropical streams, so it prefers cooler water than most tropical fish, roughly 16 to 24 C, with a pH from about 6 to 7.5. Recreate the flow with a powerhead and a strong filter, lay in rounded rocks and cobbles for surfaces to graze, and keep the tank mature so algae and biofilm can establish. High oxygen and cool, clean, moving water are the keys to keeping this fish healthy.
Good to know
Beaufortia kweichowensis is a member of Gastromyzontidae and grows to around 7.5 cm. Its body is disc-flat and its paired fins wrap outward to form a suction surface, an adaptation for holding onto rock in strong current rather than for swimming in open water. It lacks the erectile eye spine seen in botiid loaches. Breeding is essentially unrecorded in home aquaria, though it is a scatter spawner in the wild, and most stock in the trade is wild collected.
Did you know
Seen from above, the butterfly loach spreads its rounded, dark-spotted fins flat against the rock, and that wing-like outline is what earns it the butterfly name. The pattern also breaks up its shape against dappled streambed stones.
Weekly picks
Tank mates
Butterfly loach is a 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.

African butterfly cichlid
Anomalochromis thomasi
Freshwater3.1 in (8 cm) · 25 gal (95 L)73–81°F (23–27°C)
Striped flying barb
Esomus metallicus
Freshwater3 in (7.5 cm) · 24 gal (90 L)72–79°F (22–26°C)
Nan River loach
Hemimyzon nanensis
Freshwater2.8 in (7 cm) · 24 gal (90 L)64–75°F (18–24°C)
Taiwan barb
Puntius snyderi
Freshwater3.1 in (8 cm) · 24 gal (90 L)61–77°F (16–25°C)
Wrestling halfbeak
Dermogenys pusilla
FreshwaterBrackish2.8 in (7 cm) · 25 gal (95 L)75–82°F (24–28°C)
Guntea loach
Lepidocephalichthys guntea
Freshwater4.7 in (12 cm) · 24 gal (90 L)64–82°F (18–28°C)
Common questions
What size tank does a Butterfly loach need?
A Butterfly loach needs at least 25 gal (95 L). It spends most of its time in the bottom.
What temperature and pH does a Butterfly loach need?
A Butterfly loach is comfortable at 61–75°F (16–24°C) with a pH of 6.0–7.5.
How big does a Butterfly loach get?
An adult Butterfly loach reaches about 3 in (7.5 cm).
Related species
3.1 in (8 cm)24 gal (90 L)61–75°F (16–24°C)Pearl River hillstream loach
Beaufortia granulopinna
3.1 in (8 cm) · 24 gal (90 L)
3.1 in (8 cm)24 gal (90 L)64–75°F (18–24°C)Red hillstream loach
Beaufortia leveretti
3.1 in (8 cm) · 24 gal (90 L)
3.5 in (8.9 cm)24 gal (90 L)61–75°F (16–24°C)Ping's hillstream loach
Beaufortia pingi
3.5 in (8.9 cm) · 24 gal (90 L)
2.9 in (7.3 cm)24 gal (90 L)72–79°F (22–26°C)Zebra Borneo sucker
Gastromyzon zebrinus
2.9 in (7.3 cm) · 24 gal (90 L)
3.3 in (8.4 cm)24 gal (90 L)68–77°F (20–25°C)Ornate-tail Borneo sucker
Gastromyzon ornaticauda
3.3 in (8.4 cm) · 24 gal (90 L)
2.6 in (6.5 cm)20 gal (75 L)68–75°F (20–24°C)Spotted hillstream loach
Gastromyzon punctulatus
2.6 in (6.5 cm) · 20 gal (75 L)
