Dwarf chain loach

Quick facts

Adult size

5 cm

Lifespan

can live up to 8 years

Tank zone

bottom-mid

Temperament

peaceful

Difficulty

intermediate

Schooling

recommended 6+ (critical minimum 4, thrives at 10+)

Water parameters

Temperature

24–28°C

pH

6.0 to 7.5

Hardness

2 to 12 dGH

Tank requirements

Minimum volume

80 L

Minimum length

60 cm

Flow

moderate

Lighting

any

Substrate

sand

Driftwood

preferred

Hiding spots

needed

Open swimming room

needed

Feeding

Diet: omnivore, feeds primarily at the bottom.

Sinking pellets, frozen bloodworm, frozen brine shrimp, frozen daphnia, live blackworms, live brine shrimp, and blanched vegetables. They forage actively along the substrate and on surfaces, poking into crevices and under leaves. Small pest snails are eaten when found. The mouth is small, so micro pellets or crushed food works better than large wafers. Feed once or twice daily. They're active feeders during the day, unlike many loach species that are strictly nocturnal.

Compatibility

• One of the most community-friendly loach species. At 5–6 cm adult size, they fit into tanks starting at 60 L and play well with most peaceful species.
• Social and must be kept in groups of 6+. In smaller numbers they're shy and hide constantly. In groups of 8-12, they form a loose school that moves through the tank investigating surfaces and interacting with each other.
• Good with small tetras, rasboras, corydoras, shrimp (they ignore adult shrimp), and small peaceful cichlids. The main incompatibility is with very slow or very large aggressive species.
• Will eat small pest snails. Not as effective as clown loaches or yoyo loaches at clearing a snail infestation, but they pick off small bladder snails and ramshorns.

Habitat

Native to the Mae Klong River basin in western Thailand, a geographically restricted range that raised conservation concerns. The species was thought extinct at one point before being rediscovered, and wild collection was heavy in the early years of its availability in the hobby. Now commercially bred in sufficient quantities that wild pressure has eased, though the species remains uncommon compared to more widely distributed loaches. The body is pale silver-gold with a chain-like pattern of dark markings along the lateral line (hence 'chain loach'). The pattern varies between individuals and changes somewhat with mood. Adults reach 5–6 cm, making them one of the smallest Ambastaia (formerly Yasuhikotakia) species. The species (Ambastaia sidthimunki) was described by Klausewitz in 1959. Unlike most loaches, dwarf chain loaches are active during daylight hours and spend significant time in the midwater column, not just on the substrate. This daytime activity and schooling behavior make them more visible than typical loaches.

Breeding

Rarely bred in home aquariums. Occasional reports describe spontaneous spawning in large, well-established tanks with strong current, soft water, and a large group of adults. The specifics of triggering consistent breeding are not well documented in the hobby literature. Commercial breeding uses controlled environmental manipulation in dedicated facilities. Sexing is difficult; mature females may be slightly rounder. Eggs are reportedly scattered among rocks and gravel in areas with current. The scarcity of breeding reports despite decades of hobbyist keeping suggests that the required conditions are narrow. Most dwarf chain loaches in the trade are commercially bred in Southeast Asia.

Common problems

Shyness in small groups is the most common issue. Groups under 6 hide and rarely show themselves. The solution is always more loaches. Ich can appear in newly purchased fish; treat with temperature elevation (29–30°C) rather than chemical medication, as loaches in general are sensitive to common ich treatments. The species is sensitive to sudden water parameter changes; acclimate slowly when introducing new fish. Skinny disease (internal parasites from wild-caught or poorly maintained farm stock) causes progressive wasting; treat with levamisole. Availability can be inconsistent; the species isn't always in stock and commands a higher price than common loaches. Once established in stable water, they're hardy and long-lived (8-12 years).

Bioload

Bioload coefficient: 1.5 (tiny loach; light waste).

Bioload coefficients are calibrated against the neon tetra as the anchor (1.0). See the methodology page for the formula and how each value was derived.

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size