Yasuhikotakia morleti is the skunk loach, an aquarium loach reaching 8–10 cm and associated in nature with Thailand and Mekong-region tributaries with sand, leaf litter, and moderate flow. Its care is straightforward only when the aquarium is built around adult size, substrate, social structure, and oxygen rather than around the idea that all loaches are generic bottom fish.
Part of the Complete Loaches Guide.
Identification
Healthy skunk loach are identified first by body shape and behaviour. The adult size is 8–10 cm; juveniles may look harmless in dealer tanks, but the adult footprint and group requirement decide the aquarium. The mouth is directed downward or forward-low, with barbels used to test the feeding surface. The black dorsal stripe is clear; the temperament is the harder identification lesson.
| Character | What to look for | Why it matters |
|---|---|---|
| Adult size | 8–10 cm | Tank plans should use adult dimensions, not sale size |
| Substrate use | sand with dense cover and multiple narrow shelters | Barbel health and normal feeding depend on the surface |
| Social pattern | six or more to spread aggression | Solitary fish often show stress or abnormal aggression |
| Handling | Use containers or coarse nets for spined botiids; avoid chasing any loach through fine mesh | Loaches abrade easily and many botiids have suborbital spines |
Sexing is usually unreliable outside breeding condition. Mature females often become deeper-bodied when well fed, but this is not a safe method for buying pairs. Colour also changes with stress, age, diet, and lighting, so body form and provenance are better guides than intensity.
Origin & Habitat
This species is recorded from Thailand and Mekong-region tributaries with sand, leaf litter, and moderate flow. That habitat should be translated into aquarium structure, not copied as decoration. The useful aquarium target is 24–28 °C, GH 3–12 °dH, KH 1–6 °dH, pH 6.5–7.8, and conductivity around 120–400 µS/cm. These numbers sit inside a larger natural range, but they give a reproducible starting point for long-term care.
Water quality should be stricter than the broad pH range suggests. Ammonia and nitrite must remain 0 mg/L. Nitrate should stay below 20 mg/L, with 5–10 mg/L preferable in cool, high-flow systems. If hardness and alkalinity terms are still unclear, read water hardness: GH and KH explained before altering tap water.
Aquarium Husbandry
Provide 160 litres for a group; larger if community tankmates are included. Use sand with dense cover and multiple narrow shelters, then add cover so the fish can choose between exposed feeding lanes and retreat. Smooth stones, wood, leaf litter, rhizome plants, and shaded caves are all useful when they match the species' natural structure. A mature biological filter is non-negotiable; loaches feed close to the surface where waste collects, so unstable cycling damages them early. Cycling a new aquarium is required reading before adding any loach to a fresh tank.
| Parameter | Target |
|---|---|
| Temperature | 24–28 °C |
| GH | 3–12 °dH |
| KH | 1–6 °dH |
| pH | 6.5–7.8 |
| Conductivity | 120–400 µS/cm |
| Minimum social unit | six or more to spread aggression |
The best planting is tough and rooted or attached out of the main digging line. Java fern, anubias nana, and established cryptocoryne wendtii all work in many loach aquaria. Delicate stems in loose gravel are a poor match for digging, chasing, or high current.
Tankmates & Behaviour
The skunk loach is small but sharp-tempered, often nipping slow fish and dominating the bottom. Keep six or more to spread aggression. This point is not ornamental advice; it determines feeding confidence, aggression distribution, and disease resistance. Single social loaches may survive for years while never behaving normally.
Good tankmates share temperature, oxygen demand, and temperament. Quiet soft-water loaches can live with cardinal tetra, rummynose tetra, honey gourami, or pearl gourami where current and temperature match. More boisterous botiids need faster, robust fish and should not be placed with slow long-finned species. Bottom-feeder comparisons with bronze corydoras, sterbai corydoras, and bristlenose pleco are useful, but do not crowd the same floor area with too many competing species.
Diet
In captivity feed worms, insect larvae, sinking foods, small snails, and crustacean-based foods. Food must reach the bottom in good condition. In community tanks, mid-water fish often intercept everything before loaches feed; after-dark feeding and multiple feeding points prevent thin bellies. Remove uneaten food within a few hours because decay in sand or stone crevices produces bacterial load exactly where loaches probe.
Snails, if eaten, should be considered enrichment rather than a job. A loach bought only to control snails becomes a welfare problem when the snail population falls or the fish outgrows the tank. Correct overfeeding first.
Breeding
Home breeding is uncommon for many traded loaches and poorly documented for some imports. Conditioning requires stable water, heavy feeding with invertebrate foods, seasonal water changes, and secure spawning cover. Eggs, when produced, are usually vulnerable to adult predation. Commercial production may rely on outdoor ponds or hormone induction for several botiids, which is why regular shop availability does not mean easy aquarium breeding.
The practical breeding advice is conservative: maintain a mature group, feed varied foods, and record temperature, conductivity, and water-change patterns if spawning behaviour appears. Do not buy presumed pairs from a tray of juveniles; sexing is too uncertain.
Common Problems
The main failure is assuming small size means peaceful behaviour. Secondary failures include adding loaches before the filter is mature, keeping social species alone, using abrasive gravel, and treating them as scavengers. Quarantine new imports for two to four weeks; see the quarantine tank protocol. Watch for pinched bellies, clamped fins, rapid breathing, white patches on barbels, and refusal to feed after the first week.
Medication deserves care. Scaleless or lightly scaled fishes, and bottom dwellers exposed to compounds settling in mulm, can react badly to harsh treatments. Identify the disease before medicating, raise aeration, and avoid guesswork.
See Also
- The Complete Loaches Guide — taxonomy, family-level care, and handling cautions.
- Dwarf Chain Loach — useful sibling comparison.
- Tiger Loach — related loach with different husbandry emphasis.
- Yoyo Loach — another loach often considered by the same aquarists.
- Substrate Selection — sand, stone, and bottom-feeder safety.
- The Complete Catfish Guide — comparison with true catfish substrate feeders.
Frequently Asked Questions
What tank size does the skunk loach need?
Use 160 litres for a group; larger if community tankmates are included. The footprint matters as much as volume because this fish lives near the bottom and uses cover, current, or sand rather than open height.
What water parameters suit the skunk loach?
Aim for 24–28 °C, GH 3–12 °dH, KH 1–6 °dH, pH 6.5–7.8, and conductivity around 120–400 µS/cm. Keep ammonia and nitrite at 0 mg/L and nitrate preferably below 20 mg/L.
How many skunk loach should be kept together?
Six or more to spread aggression. Social loaches kept singly often hide, pine, or redirect aggression toward unrelated tankmates.
What is the common husbandry mistake with this species?
The usual mistake is assuming small size means peaceful behaviour. Correct substrate, group size, and oxygenation prevent more losses than any medication.
Sources & References
- Kottelat, M. (2012). Conspectus Cobitidum: an inventory of the loaches of the world. The Raffles Bulletin of Zoology, Supplement 26.
- FishBase — Cobitoidea and species accounts. https://www.fishbase.se/
- Fricke, R., Eschmeyer, W.N. & Van der Laan, R. Catalog of Fishes. California Academy of Sciences.
- Kottelat, M. (2001). Fishes of Laos. WHT Publications.