Reticulated Hillstream Loach
Sewellia lineolata
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.
Reticulated Hillstream Loach At a Glance
Reticulated Hillstream Loach Tank Requirements
Will Reticulated Hillstream Loach fit in your tank?
Care guides tell you what Reticulated Hillstream Loach needs, the next question is whether your tank can safely provide it. Test Reticulated Hillstream Loach against your tank size, maintenance needs, and the fish you already keep before you buy.
Reticulated Hillstream Loach Water Parameters
Reticulated Hillstream Loach Temperament & Compatibility
Reticulated Hillstream Loach 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 Guide 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 6.5–7.5 and a general hardness of 4–15 dGH. A high water flow is preferred.
Due to its specialist needs, the Reticulated Hillstream Loach is best suited for fishkeepers who can provide a carefully planned setup. The Reticulated Hillstream Loach is typically available in one standard form.
Reticulated Hillstream Loach Habitat Setup
When setting up an aquarium for the Reticulated Hillstream Loach, a high water flow best suits their natural preferences. Because this species occupies the bottom zone, the aquarium layout should prioritise sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include smooth gravel or rounded substrate to protect their sensitive barbels, an established tank with natural algae growth, as they depend on it as a primary food source, and light plant coverage for partial shade.
Reticulated Hillstream Loach Compatibility Notes
Classified as mostly peaceful, the Reticulated Hillstream Loach is a social species that requires the company of its own kind to thrive. When choosing tankmates, territorial behaviour may cause issues if hiding spots or floor space are limited and their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the bottom zone can help reduce competition and territorial overlap.
Who Reticulated Hillstream Loach Is Actually For
Reticulated Hillstream Loach is best for a fishkeeper who wants a species that can settle into a calmer community setup and can provide a keeper who can commit to a proper group of at least 3. It makes the most sense for a hobbyist who will actually build around its needs, especially smooth gravel.
The most common mistake is buying Reticulated Hillstream Loach for looks first and only later discovering how its adult size, behavior, or bioload changes the whole tank plan. Another frequent problem is underestimating its social needs. A token pair or trio often behaves very differently from a real group.
Reticulated Hillstream Loach Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Reticulated Hillstream Loach.
30 Gallon Breeder
40 Gallon Breeder
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
Show 10 more tank sizes
Frequently Asked Questions About Reticulated Hillstream Loach
How big does Reticulated Hillstream Loach get?
Reticulated Hillstream Loach (Sewellia lineolata) typically reaches a maximum adult size of approximately 6.5 cm. They have a depressed body shape and a slow growth rate.
What tank size does Reticulated Hillstream Loach need?
A minimum aquarium volume of 80 litres and a tank length of at least 90 cm are recommended for Reticulated Hillstream Loach. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Reticulated Hillstream Loach need?
Reticulated Hillstream Loach thrives in freshwater only conditions with a temperature range of 20–24°C, a pH between 6.5 and 7.5, and a general hardness of 4–15 dGH. A high water flow is preferred.
Is Reticulated Hillstream Loach peaceful or aggressive?
Reticulated Hillstream Loach is classified as mostly peaceful with an aggression score of 3 out of 10. They are generally well-suited to peaceful community tanks.
Can Reticulated Hillstream Loach live alone?
No, Reticulated Hillstream Loach should be kept in groups of at least 3 to reduce stress and encourage natural behaviour.
Does Reticulated Hillstream Loach have any special tank requirements?
Yes. Reticulated Hillstream Loach benefits from smooth gravel (sensitive barbels), established algae (otocinclus), and plants - lighly covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Useful setup supplies
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Guidarium Editorial Desk
Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.
- Last reviewed
- April 28, 2026
- Last updated
- April 28, 2026
- Issues or corrections?
- Contact the editorial team
Top Tank Mates for Reticulated Hillstream Loach
These fish are strong compatibility matches for Reticulated Hillstream Loach based on water preferences, temperament, adult size, and tank behavior.
Scissortail Rasbora
Rasbora trilineata
Ideal Tank MatesRosy Red Minnow / Fathead Minnow
Pimephales promelas
Ideal Tank MatesRose Danio
Danio roseus
Ideal Tank MatesSunset Platy (Variatus Platy)
Xiphophorus variatus
Ideal Tank MatesTiger Danio
Devario maetaengensis
Ideal Tank MatesWestern Rainbowfish
Melanotaenia australis
Ideal Tank MatesPlants That Suit Reticulated Hillstream Loach
These plants pair well with Reticulated Hillstream Loach based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
African Water Fern
Bolbitis heudelotii
Capuron's Aponogeton
Aponogeton capuronii
Madagascar Lace Plant
Aponogeton madagascariensis
Boivin's Aponogeton
Aponogeton boivinianus
African Onion Plant
Crinum calamistratum
Afzel's Anubias
Anubias afzelii
Fish Similar to Reticulated Hillstream Loach
Spotted Hillstream Loach
Gastromyzon punctulatus
A highly specialized, rheophilic (flow-loving) fish adapted to cling to rocks in fast-moving streams. Their modified fins act like suction cups. They graze constantly on biofilm and algae. To thrive, they require cooler, highly oxygenated water with strong currents (like a river manifold or powerhead setup) and plenty of smooth river stones.
Hillstream Loach
Beaufortia leveretti
A fascinating bottom-dweller adapted to fast-flowing mountain streams in Asia. It features a unique, flattened body allowing it to cling to smooth rocks in heavy currents. It requires highly oxygenated, cooler water (18-24°C) with strong flow. Often confused or mislabeled in the trade with its smaller, more common cousin, Beaufortia kweichowensis. They are specialized grazers that feed heavily on biofilm and algae.
Mottled Loach
Paracanthocobitis botia
A highly active, rheophilic (current-loving) loach native to fast-flowing streams in South Asia. Known for their intricate mottled patterns and 'zipper-like' lateral line, they are boisterous and establish clear social hierarchies. They must be kept in groups to prevent bullying and require well-oxygenated water with a smooth substrate to protect their delicate barbels.
Panda Garra
Garra flavatra
A highly active, beautifully patterned benthic (bottom-dwelling) fish native to the fast-flowing, highly oxygenated streams of Myanmar. They are excellent biofilm and algae grazers. While peaceful towards other species, they establish a strict, sometimes physical pecking order among themselves. They are notorious climbers and jumpers, requiring a tight-fitting lid.
Sumo Loach
Schistura balteata
The Sumo Loach is a fascinating, highly active bottom dweller native to fast-flowing hillstreams in Myanmar. Named for their aggressive, 'wrestling' matches over territory, they require highly oxygenated water, strong flow, and plenty of visual barriers like smooth river stones. They are highly intolerant of conspecifics and other bottom dwellers in small tanks.
Leopard Pleco
Pterygoplichthys gibbiceps
The Leopard or Sailfin Pleco is a massive, heavily armored suckermouth catfish known for its striking spotted pattern and huge dorsal fin. While excellent algae eaters when young, they grow enormous, produce extreme amounts of waste, and require massive aquariums. They are notorious for uprooting plants and may suck the slime coat off flat-bodied fish (like Discus) at night.