Reticulated hillstream loach

Overview

The reticulated hillstream loach (Sewellia lineolata) looks like a tiny stingray with a leopard print. Its flattened body and huge pectoral and pelvic fins form a suction disc, letting it cling to smooth rocks in the fast, highly oxygenated streams of Vietnam and Laos, where it grazes the thin film of algae and microorganisms that coats every stone.

People love watching it glide across the glass and rocks as if it were skating. It's peaceful and shy, but it is not a fish for just any community tank: it needs cool water, strong current and a mature setup with plenty of biofilm. It's a great pick if you want to build a river-style tank with rocks and flow, and a poor one for a warm, still planted tank.

Care and tank setup

Choose a long tank: at least 20 gallons (80 L) with roughly 30 in (75-80 cm) of length, where floor space matters more than height. Focus on these points:

• Flow and oxygen: an oversized filter plus, ideally, a circulation pump. Warm, still water is the most common way these loaches are lost.
• Temperature: cool and stable. Above 77-79 °F (25-26 °C) they struggle, so keep a clip-on fan ready for summer.
• Decor: river stones, flat slates, fine gravel and some driftwood. Hardy plants tied to rocks (anubias, Java fern, bucephalandra) work well.
• Mature tank: add them only to a tank that has been cycled for months and has stones covered in biofilm.

Use a tight lid and cover the filter intake with a sponge, as they squeeze through small gaps. Keep three or more; males shove each other over the best rocks without real damage. Good tankmates are small fish that like cool, moving water, such as danios and rasboras, plus shrimp.

Feeding

In the wild it grazes algae, biofilm and tiny invertebrates. In the aquarium, biofilm helps but isn't enough: offer spirulina-based sinking wafers or gel food daily, plus frozen brine shrimp, daphnia or bloodworms a few times a week. A handy trick is to grow algae on spare rocks in a sunny bucket and swap them in. A pinched-in belly means it isn't getting enough food.

Breeding

It has been bred in home aquariums, but it isn't common or easy. In well-fed groups kept in cool, oxygen-rich water with strong flow, tiny fry sometimes appear without any help, mostly in mature, species-focused tanks. Males have broader pectoral fins and a squarer head. The fry need lots of biofilm and very fine foods during their first weeks.

Compatible tank mates

Species from our database that share water parameters, size and temperament with the Reticulated hillstream loach. Calculated from the data in each profile.

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What not to keep it with

Popular species you shouldn’t house with the Reticulated hillstream loach, and why.

• Discus: incompatible temperatures
• Clown loach: incompatible temperatures, one may eat the other due to size
• Oscar: incompatible temperatures, one may eat the other due to size, incompatible temperaments
• Ram cichlid: incompatible temperatures

Recommended equipment

What you need to keep the Reticulated hillstream loach healthy, checked against Amazon stock.