Blue Tail Borneo Loach - Gastromyzon sp.SK03

Product Details

Blue Tail Borneo Loach – Gastromyzon sp. “SK03”

The Blue Tail Borneo Loach, Gastromyzon sp. “SK03”, is a striking hillstream loach with a flattened body, gripping fins and a beautifully marked tail that can show blue-toned colour in good condition. Also sold as a Blue Tail Borneo Sucker, Borneo Sucker Loach or Blue Tail Hillstream Loach, this is a peaceful but specialist freshwater fish for mature aquariums with strong flow, high oxygen levels and plenty of natural grazing surfaces. It is best chosen by aquarists who can provide a river-style setup rather than a standard warm community tank.

Key Identification:
Common Name: Blue Tail Borneo Loach
Other Names: Blue Tail Borneo Sucker, Borneo Sucker Loach, Blue Tail Hillstream Loach, Gastromyzon SK03
Scientific Name: Gastromyzon sp. “SK03”
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 fast, shallow, highly oxygenated streams. Their natural habitat usually includes clear water flowing over smooth stones, cobbles and bedrock, with algae, biofilm and tiny invertebrates growing on submerged surfaces. Gastromyzon sp. “SK03” should be kept as a specialist Borneo hillstream fish, with care focused on clean, moving water rather than still, heavily stocked tropical community conditions.

Appearance & Adult Size:
This fish has the flattened, suction-adapted body typical of Borneo hillstream loaches, with broad pectoral and pelvic fins that help it cling tightly to rocks and glass in flowing water. The body is usually brown, grey or olive-toned with fine speckling, reticulation or mottled patterning that helps it blend into stony stream habitats. The tail is the main feature, often showing attractive blue, dark or contrasting markings depending on mood, lighting and individual variation. Adults usually reach around 4–6 cm.

Aquarium Suitability:
The Blue Tail Borneo Loach is best suited to a mature river-style aquarium with high oxygenation, strong water movement and abundant smooth stones for grazing. It can be kept in a peaceful specialist community, but it is not suitable for warm, low-flow tanks or aquariums that lack biofilm. A bright-lit setup that encourages natural algae growth, combined with smooth river stones, rounded cobbles and open flow areas, will suit this species far better than a soft, slow blackwater-style aquarium.

Recommended Aquarium Size:
A practical minimum aquarium size is around 90 litres for a small group, with a tank length of at least 90 cm preferred. Larger aquariums are recommended if keeping multiple hillstream loaches or active current-loving tank mates.

Water Conditions:
Temperature: 20–24°C
pH: 6.5–7.5
Hardness: Soft to moderately hard
Additional Notes: Clean, well-oxygenated water is essential. Provide moderate to strong flow from an external filter, powerhead or river manifold-style setup. Keep the aquarium mature, stable and well maintained. Avoid high temperatures, low oxygen, stagnant areas and dirty substrate.

Temperament & Tank Mates:
Aquarium Category: Community Fish

Blue Tail Borneo Loaches are peaceful towards most other fish but can show mild territorial behaviour with each other over favourite rocks and grazing spots. They are best kept in groups of at least three to five, provided the aquarium has enough space and hardscape. Suitable tank mates include White Cloud Mountain Minnows, small danios, peaceful rasboras, hillstream-suitable gobies, small non-aggressive barbs and other cool-water or subtropical fish that enjoy clean, flowing water. Avoid goldfish, aggressive loaches, large predators, slow warm-water fish, delicate long-finned species and any tank mates that dislike strong current.

Feeding:
This species is a surface grazer that feeds naturally on biofilm, soft algae, diatoms and tiny invertebrates living on rocks. In the aquarium, provide mature grazing surfaces and supplement with algae wafers, spirulina foods, specialist gel foods, sinking micro pellets and fine catfish foods. Offer occasional frozen or live foods such as daphnia, cyclops, brineshrimp and bloodworm, but avoid making the diet too rich in meaty foods. Blanched courgette, spinach or kale may also be accepted. They should not be added to sterile new tanks with no natural grazing growth.

Behaviour in the Aquarium:
Blue Tail Borneo Loaches spend most of their time attached to rocks, wood, glass or broad leaves, using their modified fins to hold position against the current. They graze continuously, shuffle across smooth surfaces and often choose high-flow areas near filter outlets or powerheads. They do not swim like typical loaches; instead, they glide, cling and dart between surfaces. Small disputes between individuals may involve chasing or pushing, but serious damage is uncommon in a spacious, well-scaped aquarium.

Care Notes:
This is not a general algae eater for any tank. It needs a mature aquarium, strong oxygenation, cool to moderate tropical temperatures and constant access to biofilm-rich surfaces. Keep nitrate low with regular water changes and avoid medications or treatments that may reduce oxygen levels. Use smooth stones rather than sharp décor, and make sure food reaches the bottom and grazing areas. High temperatures above the mid-20s°C can be stressful because warmer water carries less oxygen.

Recommended For:
Intermediate to experienced

Availability:
Rare to occasional; usually wild-caught or imported as a specialist Borneo hillstream loach.

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 and markings can occur between individual fish.