Tiger Hillstream Loach

Sewellia sp. 'Tiger' is an undescribed species collected from highland streams in Vietnam and, occasionally, adjacent Laos. Its defining feature is a series of bold, irregular transverse stripes of deep amber and black that create a convincing tiger-like pattern — strikingly different from the reticulated designs of its congeners. Like all Sewellia, it is a dedicated rheophilic grazer that rarely leaves the rock surfaces it calls home.

In the aquarium, this species adapts reasonably well provided the keeper replicates its cool, highly oxygenated, fast-flowing native environment. It is active throughout the day, engaged in near-constant grazing, and will readily accept supplementary foods. Territory between males can lead to occasional brief chases, but overt aggression is rare in spacious tanks with adequate visual breaks.

The Tiger Hillstream Loach is still infrequently captive-bred, making wild imports the primary source for the hobby. Buyers should be prepared to quarantine new arrivals carefully, as the stress of import can make them temporarily susceptible to bacterial infections and white spot.

Water: 18–24°C, pH 6.5–7.5, GH 4–15, KH 2–8; very high flow essential — turnover of at least 10× per hour with strong surface break. Tank: 80 L minimum, smooth boulders and flat stones; avoid fine sand which can silt onto surfaces and clog the algae grazing area. Feeding: Primarily biofilm and microalgae; offer spirulina wafers, Repashy Soilent Green, and occasional blanched greens. Breeding: Rarely bred in captivity; simulate seasonal cooling and increased flow to encourage conditioning; eggs laid under flat rocks. Compatibility: Generally peaceful; minor sparring between males is normal — provide sight breaks using stones arranged upright.