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Java Loach

Pangio oblonga (Valenciennes, 1846)

Also called Black kuhli loach, Chocolate kuhli loach, Cinnamon loach, Cobitis oblonga (original name), Acanthophthalmus javanicus (former name)

SpeciesShort profile

From Southeast and South Asia. First described from Bogor in West Java; reported from Java, Sumatra, Borneo, Peninsular Malaysia and Thailand, with FishBase also listing Indochina, Myanmar, India and Bangladesh.12

At a glance the quick version

Length8 cm123
Sizesmall
Peaceful with fish and shrimp
Fun burrowing behaviour
Small and suited to modest tanks
13

Looks how to spot one

Eel-shaped (anguilliform) loach

A long, slim, worm-like loach with small fins set far back and short barbels around the mouth. Females are heavier and larger, and mature males have a thickened, branched first ray on the pectoral fin.1

ColoursPlain chocolate brown to reddish-brown or almost black on the backPaler bellySome populations lighter or pinkish13

Personality what they are like

Gentle and sociable. Java loaches like to rest in a tangle with others of their kind and quickly dive into the sand if startled. They leave other fish alone, though they may snack on eggs or very tiny fry.13

Daily activity how busy a day looks

Mostly active at dusk and after dark, sifting through sand and leaf litter; more visible in daylight when kept in a group with plenty of cover.12

Grooming and care the hands-on bits

Fit a tight lid, as they can jump or slip through gaps. Use fine, soft sand they can burrow into, add leaf litter and plants, and keep water clean with gentle filtration and regular partial changes.13

Home where they are happiest

A base of at least 60 x 30 cm (about 54 litres). Temperature about 21 to 28 °C, pH about 3.5 to 7.0 (most guides suggest 6.2 to 7.0), very soft to soft water (0 to 8 dGH). In the wild they live in slow streams with muddy or sandy bottoms among plants and leaf litter.123

Food basics what goes in the bowl

A small bottom forager eating insect larvae, worms and tiny crustaceans. Offer sinking pellets or wafers plus live or frozen daphnia, brine shrimp, Mysis and bloodworm, ideally in the evening.123

Company who they like around

Keep in a group of at least 5 or 6. Good companions are small, peaceful fish such as rasboras, small tetras and corydoras, and dwarf shrimp.13

The story where it all began

Achille Valenciennes described the Java loach in 1846 from Bogor on Java. It is a close relative of the kuhli loach and has long been a regular in the aquarium trade, where its plain chocolate colour sets it apart from its striped cousins.13

Fun facts for the dinner table

  1. 1

    Java loaches can gulp air at the surface and absorb oxygen from it when the water is poor in oxygen.2

  2. 2

    When frightened they disappear by diving straight into the sand.3

  3. 3

    In nature they probably spawn in very shallow water in flooded forests.2

  4. 4

    They can live in remarkably acidic water, with a recorded range down to about pH 3.5.1

Recognised by the official bits

IUCN Red List
Least Concern (assessed December 2018)2
Taxonomy
Family Cobitidae. Described by Achille Valenciennes in 1846 as Cobitis oblonga; formerly placed in Acanthophthalmus. It may be a group of several closely related species.1

The care rhythm a typical week and year

A typical home-care rhythm for a Java Loach. A starting point, not a vet's advice.

Owner questions the things everyone asks

How often should I feed my Java Loach?

Feed small amounts once or twice daily, ideally in the evening when they are most active. Furry Diary's starting plan suggests feeding every day. This matches their natural foraging habits.123 Pet Wiki plan

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

They eat insect larvae, worms, tiny crustaceans, sinking pellets or wafers, and live or frozen foods like daphnia and bloodworm. For foods to avoid, it varies by individual; ask a vet or experienced breeder for specific guidance.123

How much space does a Java Loach need?

A tank with a base of at least 60 x 30 cm (about 54 litres) is recommended. This gives them room to burrow and explore with their group.123

What temperature, light or water does a Java Loach need?

Keep water temperature between 21 and 28°C, pH around 6.2 to 7.0, and very soft water (0 to 8 dGH). They prefer dim lighting and plenty of cover like plants and leaf litter to feel secure.123

How often should I clean a Java Loach's home?

Change about 25% of the water weekly, clean the glass weekly, and rinse the filter monthly in old tank water (never tap water). Furry Diary's plan includes these steps to keep water clean and gentle.13 Pet Wiki plan

Can a Java Loach live with others?

Yes, they are sociable and should be kept in a group of at least 5 or 6. Good tankmates include small peaceful fish like rasboras, small tetras, corydoras, and dwarf shrimp.13

How long does a Java Loach live?

Lifespan varies depending on care and environment. For typical longevity, ask a vet or experienced breeder.

Can I handle a Java Loach?

Handling is not recommended as they are delicate and easily stressed. If you need to move them, use a soft net or container; for specific advice, consult a vet.

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

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Where this comes from

Every fact on this page has a numbered source. Spotted an error? support@petwiki.app.

  1. Seriously Fish: Pangio oblonga seriouslyfish.comused for names, origin, size, tank and water, diet, behaviour, dimorphism, taxonomy
  2. FishBase: Pangio oblonga summary fishbase.seused for distribution, length, environment, habitat, air breathing, IUCN status
  3. Wikipedia: Pangio oblonga en.wikipedia.orgused for other names, colour, burrowing, care

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