Product Details

Double Blue Zebra Borneo Loach – Gastromyzon sp.

The Double Blue Zebra Borneo Loach is a specialist hillstream loach with a flattened body, strong gripping fins and attractive zebra-style striping that may show blue or blue-grey highlights depending on the individual fish and lighting. Also sold as the Blue Zebra Borneo Loach, Borneo Sucker Loach, Blue Zebra Hillstream Loach or Butterfly Loach, this peaceful but demanding species is best suited to a mature river-style aquarium with fast, clean, highly oxygenated water and plenty of natural grazing surfaces.

Key Identification:

Common Name: Double Blue Zebra Borneo Loach
Other Names: Blue Zebra Borneo Loach, Blue Zebra Hillstream Loach, Borneo Sucker Loach, Butterfly Loach
Scientific Name: Gastromyzon sp.
Fish Type: Hillstream Loach / Borneo Sucker Loach
Water Type: Freshwater

Natural Range & Habitat:

Gastromyzon loaches are native to Borneo and surrounding parts of Southeast Asia, where they live in shallow, fast-flowing streams and hill rivers. These habitats are usually clear, highly oxygenated and filled with smooth stones, cobbles, bedrock and natural biofilm.

The Double Blue Zebra name is a trade description rather than a confirmed species name, so exact locality can vary between imports. In the aquarium, it should be treated as a specialist Borneo hillstream fish that needs strong water movement, clean conditions and established grazing surfaces.

Appearance & Adult Size:

Double Blue Zebra Borneo Loaches have a broad, flattened body with enlarged pectoral and pelvic fins that allow them to cling tightly to rocks, glass and other hard surfaces. Their pattern is usually made up of dark and pale striping, spotting or zebra-like markings across the body and fins.

Some individuals show blue, blue-grey or dark metallic tones in the tail and fin areas, especially when settled and kept under good lighting. Adults usually reach around 4–6 cm, although size can vary slightly depending on the exact imported form.

Aquarium Suitability:

This species is best suited to a mature river-style aquarium with strong flow, high oxygen levels and plenty of smooth stones for grazing. Bright lighting can help encourage natural algae and biofilm growth, while shaded areas give the fish places to rest.

It is not suitable for sterile new aquariums, low-flow tropical tanks or setups with poor circulation. Double Blue Zebra Borneo Loaches should be viewed as specialist grazing fish, not general-purpose algae cleaners for any aquarium.

Recommended Aquarium Size:

A practical minimum is 90 litres for a small group, with a tank length of at least 90 cm preferred. Larger aquariums are better for groups of hillstream loaches or active current-loving tank mates.

Keep in a group of at least 3–5 where space and food availability allow. Provide multiple smooth rocks, open flow areas and separate grazing spots to reduce competition between individuals.

Water Conditions:

Temperature: 20–24°C
pH: 6.5–7.8
Hardness: Soft to moderately hard
Additional Notes: Strong oxygenation is essential. Provide moderate to strong flow using an external filter, powerhead or river-style setup. Keep nitrate low and avoid high temperatures, stagnant areas, dirty substrate and unstable water conditions.

Temperament & Tank Mates:

Aquarium Category: Community Fish

Double Blue Zebra Borneo Loaches are peaceful with most fish, although they may gently chase or push each other away from favourite rocks and feeding areas. This is usually territorial display rather than serious aggression when enough space and hardscape are provided.

Suitable tank mates include White Cloud Mountain Minnows, small danios, peaceful rasboras, small stream-suitable barbs, hillstream gobies and other calm fish that enjoy cool, clean, well-oxygenated water. Avoid goldfish, large predators, aggressive loaches, very warm-water species, delicate long-finned fish and slow tank mates that dislike strong current.

Feeding:

Double Blue Zebra Borneo Loaches are specialised surface grazers. In nature, they feed mainly on biofilm, soft algae, diatoms and tiny invertebrates from rock surfaces. In the aquarium, provide mature grazing surfaces and supplement with algae wafers, spirulina foods, specialist gel foods, sinking micro pellets and fine catfish foods.

Small frozen or live foods such as daphnia, cyclops, brineshrimp and occasional bloodworm can be offered, but the diet should not be too rich in meaty foods. Blanched courgette, spinach or kale may also be accepted. Do not add this fish to a newly set-up tank with no natural biofilm.

Behaviour in the Aquarium:

This is a clinging and grazing fish rather than a typical free-swimming loach. It spends much of its time attached to smooth stones, glass, wood or broad leaves, moving in short gliding bursts as it grazes across surfaces.

It often chooses high-flow areas near filter outlets or powerheads and may rest flat against rocks between feeding periods. In groups, individuals may defend small feeding spots, but serious damage is uncommon in a well-designed aquarium with enough hardscape.

Care Notes:

A mature aquarium is essential. Provide strong flow, high oxygenation, smooth stones, stable water and established biofilm. Avoid high temperatures, low oxygen, sharp décor and dirty substrates.

Make sure prepared foods reach the loaches, especially in tanks with fast midwater fish. This species is not suitable for brand-new aquariums or standard warm community tanks with weak filtration. Regular water changes and low nitrate levels are important for long-term success.

Recommended For:

Intermediate to experienced

Availability:

Rare to occasional / Usually wild-caught or imported under specialist Borneo hillstream loach trade names

Image Disclaimer:

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Natural variation in size, colour, pattern, body tone and markings can occur between individual fish.