Reticulated Hillstream Loach

Sewellia lineolata

Loaches

A fascinating, highly specialized loach adapted to fast-flowing, oxygen-rich rapids. They have a flattened, ray-like body allowing them to cling to smooth rocks where they graze on algae and biofilm (aufwuchs). They strictly require strong water flow, high dissolved oxygen, and cooler temperatures. Males frequently engage in visually striking but harmless territorial 'battles' over prime feeding rocks.

At a Glance

Adult Size6.5 cm
Body ShapeDepressed
Growth RateSlow
TemperamentMostly Peaceful
Water TypeFreshwater Only
Flow PreferenceHigh
Waste OutputLow
StockingGroup of 3+

Tank Requirements

Minimum Volume80 L
Minimum Length90 cm
FlowHigh
Water TypeFreshwater Only
Must-Haves in the Tank
Smooth Gravel (Sensitive Barbels)Established Algae (Otocinclus)Plants - lighly covered

Water Parameters

Temperature2024°C
pH6.57.5
Hardness415 dGH

Temperament & Compatibility

Aggression LevelMostly Peaceful
3/10
Where They Swim
Surface
Mid-level
Bottom
Stocking Guidelines
Keep at Least3 fish
Max per TankNo limit
Can Live Alone?No — needs a group
Behavior Traits
Hyperactive / Fast SwimmerTerritorial (Defends specific area)

Available Varieties

Each variety inherits the species defaults above. Only differences are highlighted.

Standard

The standard wild-type Reticulated Hillstream Loach. To thrive, ensure a unidirectional flow setup (river manifold) and plenty of smooth river rocks illuminated by strong light to promote algae growth.

Same care requirements as the base species

Also known as: Wild Type

Reticulated Hillstream Loach Care Summary

The Reticulated Hillstream Loach, scientifically known as Sewellia lineolata, belongs to the Loaches family group. Adults reach a maximum size of approximately 6.5 cm and have a depressed body shape with a slow growth rate. Classified as mostly peaceful, this species primarily occupies the bottom zone of the aquarium and produces a low level of biological waste.

To thrive, the Reticulated Hillstream Loach requires a freshwater only aquarium with a minimum volume of 80 litres and a tank length of at least 90 cm. Water temperature should be maintained between 20°C and 24°C, with a pH range of 6.57.5 and a general hardness of 415 dGH. A high water flow is preferred. To replicate their natural habitat, the tank should include smooth gravel (sensitive barbels), established algae (otocinclus), and plants - lighly covered.

This species should be kept in groups of at least 3 to reduce stress and encourage natural behaviour. Keepers should be aware that this species will defend a territory within the tank. The Reticulated Hillstream Loach is typically available in one standard form.


Similar Species

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