Marbled Hillstream Loach – Sewellia marmorata

Marbled Hillstream Loach (Sewellia marmorata) is a beautifully patterned freshwater loach with an eye-catching marbled body and distinctive flattened shape designed for life in fast-flowing streams. This fascinating species is highly sought after by aquarists who love unusual algae-grazers and river-tank specialists.

With its ornate patterning, graceful gliding movement, and unique body form, Sewellia marmorata makes a superb addition to mature, well-oxygenated aquariums. It is especially well suited to tanks with strong flow, smooth stones, and surfaces where biofilm and algae can naturally develop.

Care Requirements

Scientific Name	Sewellia marmorata
Common Name	Marbled Hillstream Loach
Temperament	Peaceful, active, specialist bottom-dweller
Adult Size	5–7 cm
Tank Size	70 litres+
Temperature	20–25°C
pH	6.5–7.5
Diet	Algae, biofilm, sinking foods, frozen foods
Compatibility	Best with peaceful fish suited to cooler, oxygen-rich aquariums

Feeding Guide

Offer a varied diet including algae wafers, quality sinking foods, repashy-style gel foods, and occasional frozen foods such as bloodworm or daphnia. Established biofilm and natural grazing surfaces are especially important for long-term success.

Tank Setup & Habitat

Marbled Hillstream Loaches thrive in mature aquariums with high oxygenation, strong water movement, smooth rocks, and clean, stable water. River-style setups with circulation pumps, rounded stones, and algal growth are ideal for this species.

Compatibility

This species is best kept with other peaceful fish that appreciate cooler, well-oxygenated water such as danios, white cloud mountain minnows, and other suitable river-tank companions. Avoid aggressive or boisterous tank mates.

Health & Wellness

Excellent water quality is essential. Hillstream loaches are sensitive to poor oxygenation and unstable conditions, so regular maintenance and mature filtration are key to keeping them healthy.

Acclimation Guide

Float the bag to equalise temperature, then slowly add aquarium water over 20–30 minutes before release. Introduce only into fully cycled, well-oxygenated aquariums.

Frequently Asked Questions

Is this listing for one fish?
Yes, this listing is for 1 Marbled Hillstream Loach.

Does this fish eat algae?
Yes, it will graze algae and biofilm, but it also needs a varied prepared diet.

Can it live in a standard tropical community tank?
It prefers cooler, highly oxygenated setups and does best in suitable river-style aquariums.

Is it peaceful?
Yes, it is peaceful and works well with carefully chosen tank mates.

What makes it special?
Its stunning marbled pattern, unusual body shape, and stream-dwelling behaviour make it a standout species.