Furry Diary

Not furry, but we like them anyway.

Reticulated Hillstream Loach

Sewellia lineolata (Valenciennes, 1846)

Also called Tiger hillstream loach, Vietnamese hillstream loach, Gold ring butterfly sucker

SpeciesShort profile

From Fast hill streams of central Vietnam (Thua Thien-Hue, Quang Nam, Quang Ngai and Binh Dinh provinces), with records from the Mekong basin in Laos; FishBase also lists China and Cambodia.123

A friendly guide, not veterinary advice. For anything about your pet's health, ask your vet.

At a glance the quick version

Length5.7 to 6.5 cm21
Sizesmall

Standard length; FishBase gives 5.7 cm, Seriously Fish 6.5 cm.

Eye-catching tiger-striped pattern
Peaceful with other fish
Busy grazer that tidies algae film from rocks and glass
13

Looks how to spot one

Flattened hillstream loach

A low, flat-bellied little fish whose wide pectoral and pelvic fins spread out like a skirt, letting it press itself against rocks in strong current. Each side carries three to five bold dark stripes, and the paired fins show one or two neat concentric bands. Males have a squarer snout and develop small tubercles on the pectoral fin rays; females are broader.123

Coloursbold dark longitudinal stripesbanded paired fins12

Personality what they are like

Calm and inoffensive toward tankmates. Among their own kind, males hold small patches of rock and will push each other around briefly, which is part of their natural display rather than real conflict.1

Daily activity how busy a day looks

Active during the day, constantly gliding from stone to stone and grazing. Unlike many loaches they ride the current for short distances before settling again, so open rock surfaces and strong flow let them show this behaviour.23

Grooming and care the hands-on bits

Water: 20 to 24 C, pH 6.0 to 7.5, hardness 1 to 10 dGH. Needs very clean, oxygen-rich water with strong flow; Seriously Fish suggests filtration turning the tank volume over 15 to 20 times an hour, plus regular partial water changes.1

Home where they are happiest

A river-style tank with a base of at least 75 x 30 cm (about 68 litres), smooth stones, pebbles and sand, bright light so algae film grows on the rocks, and powerheads for a strong current. Hardy plants such as Anubias or Java fern suit the flow.13

Food basics what goes in the bowl

In nature they graze biofilm, algae and tiny organisms off stones and take some insect larvae. In the aquarium offer algae wafers, sinking dried foods, vegetable-based foods and small frozen foods such as bloodworm, daphnia or brine shrimp, alongside natural algae growth.123

Company who they like around

Lives in large groups in the wild; keep at least six so their natural social behaviour shows. Best with calm, cooler-water tankmates that will not compete heavily for food on the bottom.1

The story where it all began

Valenciennes named the species in 1846 from material first recorded by the collector Diard. It then went unrecorded for well over a century until fresh collections in the early 1990s brought it back to light, after which it reached the aquarium trade.13

Fun facts for the dinner table

  1. 1

    It was effectively lost to science for more than 150 years between its first collection and its rediscovery in the early 1990s.1

  2. 2

    Instead of hopping from rock to rock, it lifts off and glides on the current for a short distance before landing again.3

  3. 3

    Its paired fins work together like a suction pad, letting it cling to stones in fast, shallow rapids.3

  4. 4

    Hillstream loaches as a family number around 137 species in 18 genera across China and Southeast Asia.4

Recognised by the official bits

IUCN Red List
Vulnerable (assessed 5 September 2010)2
Taxonomy
Family Gastromyzontidae (hillstream loaches); described by Valenciennes in 18463

The care rhythm Furry Diary remembers it for you

A typical home-care rhythm for a Reticulated Hillstream Loach. It is our own starting plan, not a vet's advice, and you can change every line in the app.

Tell me when it launches

Owner questions the things everyone asks

How often should I feed my Reticulated Hillstream Loach?

Feed small amounts once or twice a day. Furry Diary's starting plan suggests daily feeding, but watch your fish and adjust so no food goes to waste.1 Furry Diary plan

What does a Reticulated Hillstream Loach eat, and what should it never eat?

They graze on algae and tiny organisms in nature. Offer algae wafers, sinking dried foods, vegetable-based foods, and small frozen foods like bloodworm or daphnia. Never feed them large or floating foods that they cannot reach on the bottom.123

How much space does a Reticulated Hillstream Loach need?

A river-style tank with a base of at least 75 x 30 cm (about 68 litres) is recommended. This gives them room to glide and graze on smooth stones and pebbles.13

What temperature, light or water does a Reticulated Hillstream Loach need?

Keep water at 20 to 24°C, pH 6.0 to 7.5, and hardness 1 to 10 dGH. They need very clean, oxygen-rich water with strong flow, bright light for algae growth, and filtration that turns the tank volume over 15 to 20 times an hour.1

How often should I clean a Reticulated Hillstream Loach's home?

Furry Diary's starting plan suggests a weekly 25% water change, weekly glass cleaning, and monthly filter rinsing in old tank water (never tap water). Regular testing is also recommended. Furry Diary plan

Can a Reticulated Hillstream Loach live with others?

Yes, they are calm and inoffensive. Keep at least six of their own kind to show natural social behavior, and choose calm, cooler-water tankmates that won't compete heavily for bottom food.1

How long does a Reticulated Hillstream Loach live?

Lifespan varies depending on care and environment. For specific information, consult a good breeder or an exotic-pet vet.

Can I handle a Reticulated Hillstream Loach?

It is best not to handle them. They are delicate fish that need to stay in water, and handling can cause stress or injury. Enjoy watching them glide over rocks instead.23

Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Furry Diary's own starting care plan. A friendly guide, not a vet's advice.

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Where this comes from

Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at [email protected] and we will fix it.

  1. Seriously Fish: Sewellia lineolata seriouslyfish.comused for names, range, size, care, behaviour, history
  2. FishBase: Sewellia lineolata fishbase.seused for size, range, IUCN status, biology
  3. Wikipedia: Sewellia lineolata en.wikipedia.orgused for taxonomy, behaviour, diet, aquarium notes
  4. Wikipedia: Gastromyzontidae en.wikipedia.orgused for family facts
  5. VCA Animal Hospitals: Feeding times and frequency for your dog vcahospitals.comused for owner questions
  6. ASPCA: Dog grooming tips aspca.orgused for owner questions
  7. ASPCA: Cat grooming tips aspca.orgused for owner questions
  8. ASPCA: People foods to avoid feeding your pets aspca.orgused for owner questions
  9. RSPCA: What to feed your rabbit rspca.org.ukused for owner questions

Checked 2026-09-30. Text is written in our own words from these sources.