What To Know About Kuhli Loach

Reviewed by Vanesa Farmer, DVM on December 02, 2022

Fishkeeping is a popular hobby enjoyed by over 12 million American households. An aquarium filled with colorful freshwater fish can add natural beauty to your home and help you learn more about marine life. You can choose from thousands of species of freshwater fish, ranging from tiny guppies to enormous pufferfish.

The kuhli loach is a common, low-maintenance fish, suitable for beginner aquarium owners — also called aquarists. The kuhli loach is a small, colorful fish that resembles an eel.

This species can make a great addition to many freshwater tanks if you can satisfy its needs. Read on to learn about the features and care requirements of keeping this unique fish as a pet.

The kuhli loach (Pangio kuhlii) is a freshwater fish that originated in Borneo, Java, Malaysia, and Sumatra. The fish goes by several names, including: 

  • Ancanthophthalmus kuhlii
  • Coolie loach 
  • Giant coolie loach
  • Kuhl’s loach  
  • Leopard eel
  • Leopard loach
  • Prickly eye
  • Striped loach

This fish has a distinct appearance that makes it popular with many aquarists. It has a long, slender, eel-like body. Kuhli loach colors include a salmon-pink body with thick black or dark brown stripes. It has a white stomach and small, translucent fins. 

Three pairs of barbels — or whiskers — grow near the fish’s mouth. Tiny appendages also grow around the eyes, giving the fish its genus name Ancanthophthalmus, which stands for “thorn eye”. 

In the wild, the kuhli loach habitat includes freshwater bodies like lowland forest canals, hill streams, and peats. In Singapore, populations of wild kuhli loach have decreased dramatically, possibly because of habitat loss, pollution, and declining nutrient levels in the ponds where some fish live.

Proper kuhli loach care includes the right aquarium set-up and water conditions. The fish requires a minimum tank size of 20 gallons. Its eel-like body can easily squeeze through small gaps, so keep your tank securely covered to prevent an escape. 

The proper water temperature for a kuhli loach ranges from 75 to 85 degrees Fahrenheit. The aquarium water should have a pH of 6 to 7, and the ideal water hardness level is medium soft to medium. Sudden water changes can harm the fish, so experts advise only placing your loach into an established tank that has completed the nitrogen cycle. 

The fish enjoys hiding and squeezing into tight spaces. Using sand or smooth stones as a substrate will prevent the fish from injuring itself on jagged gravel. It’s also best to avoid placing any sharp decorations into the aquarium, which could pose a safety hazard for this curious fish. The adventurous kuhli loach also thrives in a tank with many plants, empty rocks, logs, and other hiding spaces.

The kuhli loach is a non-aggressive and serene fish that prefers to live in schools of at least three fish. This species gets along best with other small, peaceful fish. Examples of acceptable tank mates include: 

  • Corydora
  • Danio
  • Gourami 
  • Oto Catfish
  • Rasboro
  • Shrimp
  • Tetra
  • White Cloud Mountain Minnows

Avoid housing the kuhli loach with large predatory fish, like Cichlids. Species of fish prone to nipping their tank mates, like Angelfish and Tiger Barbs, should also not be kept with a kuhli loach. Finally, it’s best not to include snails in your tank, because the kuhli loach may eat them.

The kuhli loach diet should include plenty of protein to keep this carnivorous fish satisfied. You can feed your kuhli loach food pellets and live foods like bloodworms and brine shrimp. Since this fish is nocturnal, they prefer to eat at night in dark lighting. 

When kept in captivity, the average kuhli loach lifespan is 10 years. However, some specimens have lived longer. Keeping the tank clean and heated to the proper temperature can prevent diseases and help your kuhli loach live for a long time. 

The size of the kuhli loach depends on whether it lives in the wild or captivity. Wild kuhli loaches can grow up to 5 inches, while kuhli loaches bred and raised in captivity may only grow between 3 and 4.5 inches. 

The relatively small size of the kuhli loach makes it a good choice for beginner fishkeepers and people living in small spaces who want to avoid investing in a giant tank. You can keep this fish in a 20-gallon tank without fear that it will outgrow the space.

Most kuhli loaches are bred in captivity in their native regions. For instance, Thai fisheries supply many loaches for the global fish trade. 

It’s possible to breed these fish at home in specific circumstances. You should keep the fish in a kuhli loach-only tank with a gravel filter for best results.

If you're looking for a visually unique but easy-to-care-for fish, the kuhli loach can be a great choice. It’s a curious fish that can provide hours of entertainment as it explores its tank and squeezes into hiding spaces.

Kuhli loaches also cohabitate peacefully with fish of similar sizes and temperaments, making them an excellent addition to many freshwater tanks.

The kuhli loach can also be a significant commitment due to its 10-year lifespan. But, if you can provide long-term care for this low-maintenance fish, it can make an excellent pet.

Show Sources

Aqua Fauna Research: “Kuhli Loach.”
Fishbase: “Pangio kuhlii (Valenciennes, 1846).”
Florida Department of Agriculture and Consumer Services: “Aquarium Fish.”
Nature Society (Singapore): “Saving the Freshwater Loaches, Rasboras, and Gouramies.”
Owen, M. FishLore.com Freshwater Aquarium e-Book, FishLore, 2013.
Thai Fisheries Gazette: “Aquarium fish industry in Thailand [1998].”
University of Wisconsin-Madison: “Loaches.”
USGS: “Pangio kuhlii (Valenciennes in Cuvier and Valenciennes, 1846).”

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