Kuhli Loach: What To Know Before Buying This Loach

The Kuhli Loach is a small loach that lives at the bottom of the tank.

Their vibrant colors and algae eating ability have made this loach very popular.

This is an excellent oddball fish to add to a tropical community tank. They are very peaceful and spend most of their time hiding away.

Kuhli Loach are helpful cleaner loaches that scavenge on any leftovers and algae at the bottom of your aquarium. They can be valuable in helping you maintain a clean tank.

If you are thinking of adding this loach to your freshwater tank, read on for everything you need to know about this Coolie Loach.

Kuhli Loach 101

The Kuhli Loach is a small sized bottom dweller from Southeast Asia.

Kuhli Loach actually refers to several species in the Pangio genus, however when most people think of this species they think of the most common color variety – a brown body with 6 to 10 bright yellow or orange bands. This is the species that we know as Pangio kuhlii and will be the focus of this article.

Other species that are also known as Kuhli Loaches include the Black Kuhli Loach (Pangio oblonga), Pangio anguillaris, and Pangio pangia. You will often find them being sold as other color forms of Pangio kuhlii.

The Kuhli Loach, or Coolie Loach, is a member of the family Cobitidae.

Although they are quite uncommon in pet shops you can purchase them from online aquarium suppliers for $3-$5 per fish.

They are loved because they make excellent tank cleaners. They will gobble up absolutely anything they can find at the bottom of the tank (including algae and leftover food).

You can expect them to live anywhere from 10 to 14 years.

Key Facts:

• Experience Required: Freshwater fishkeeping and scaleless fish.
• Nicknames: Coolie Loach, Kuhl’s Loach.
• Color Forms: Brown and yellow banded (most common).
• Size: 4 inches.
• Tank Size: Minimum 30+ gallon.
• Tank Temperature: 74°F to 85°F.

Kuhli Loach Care Guide

The biggest challenge with keeping Kuhli Loaches is their scaleless head.

This makes them much more vulnerable to diseases and parasites than other fish species.

In fact they will often be the first fish in your tank to be infected.

If your loach does get sick they cannot take the same medications as your scaled fish. Their lack of scales also leaves them open to allergic reactions. Because of this you really need to keep on top of the water changes and conditions.

Kuhli Loaches are also more prone to cuts and scrapes (especially if the substrate is too rough). Skin injuries and lesions are more visible on a fish with little to no scales.

Because they spend most of their time in the substrate, they can get a nasty bacterial infection if the substrate is not kept very clean. You must rinse your substrate every time you clean your tank (every 2 weeks).

Diet

In the wild Kuhli Loaches are scavengers and will eat a little bit of everything.

They use their barbels to probe the substrate and will gobble up anything they can find.

Zooplankton, algae, larvae, and micro worms are on the menu in this fish’s natural habitat. They will also eat any carrion that makes it way to the bottom of the tank.

Any food that you give them must be easy to access at the bottom of the tank. Pellet and flake foods should be quick sinking so that your other fish will not snatch them up before they hit the bottom.

You should also offer them live prey that this fish would be used to hunting in the wild. These include water fleas, larval brine shrimp and micro bloodworms. Every so often you can give them frozen bloodworms or brine shrimp as a treat. However they will prefer to eat their prey live.

They will also eat any algae that grows along the bottom of your tank.

Cooked vegetables (such as spinach and lettuce) make a healthy addition to their diet. Just make sure that they are crushed small enough to fit into their mouth.

These fish will come out to feed just after sundown and will eat continuously until dawn. They need up to 3 feedings per night and will spend most of their time scavenging.

Here are all of the things that a Kuhli Loach can munch on: Fish flakes, Pellet foods, Water fleas, Larval brine shrimp (live and frozen), Adult brine shrimp (live and frozen), Micro bloodworms (live and frozen), Algae, Carrion, Small shrimp, Spinach, Lettuce, Cucumbers and Zucchini.

Behavior

They do not like company outside of their own kind however they will interact with small fish that visit the bottom of the tank.

When surrounded by other Kuhli Loach these fish are quite social. They will feed in groups and gather around a single prey item together. They may bury into the substrate every so often but they will not dig up your plants. You might also catch them stalking your other bottom dwellers once in a while.

This fish spends most of its time hiding during the day. They will seek out dark and secluded areas to hide in and love to hide out in leafy plants and under logs.

You will not see them until your other fish go to sleep and it gets dark.

When they are not able to hide they will play dead at the bottom of your tank. They will look like they are sleeping, but they are actually just trying to stop other fish getting close.

Interestingly they will hide more often when they are sick or injured.

Habitat and Aquarium Set Up

These bottom dwelling fish come from the warm waters of Southeast Asia.

In the wild they will stay close to the substrate in low flow areas of streams and channels. Very little light reaches the depths where these fish live, so they use their barbels to find their way around.

The water is murky, slightly acidic and heavily shaded.

Mosses (like Java Moss), leaves and floating plants offer both security and breeding space for this secretive little critter. It is drawn to areas with thickets and plants with very large leaves.

It is your job to replicate these conditions inside your aquarium.

Aquarium Conditions

First of all, you will need to keep Kuhli Loaches in at least a 30 gallon aquarium. Some aquarists will say that this fish can handle a tank size as small as 20 gallons. However, since they prefer to live in groups of up to 5, it is better to size up to at least 30 gallons.

You will need to keep the water heated to anywhere between 74 and 85°F. As for the pH, it should range between 5.5-6.5 (mild to moderately acidic). The water hardness should be exactly 5 dGH.

A low flow undergravel filter is the best kind for a Kuhli Loach. Your loach will spend most of their time in the gravel, so do not use anything that stirs up too much of the substrate.

Now for lighting you will need to keep the lights down low and provide adequate shade at the bottom levels of the tank.

It is very important that your substrate is soft and fine because this fish can get cut or scraped by rough substrate.

They also need plenty of hiding places to feel secure so you can include logs and caves. When picking out hiding places, you should only pick objects with smooth edges. Try logs, driftwood and PVC caverns. If you do use rocks, make sure that they are completely smoothed down.

Plants make the best shelter for a bottom dweller.

Java, sphagnum or peat moss will be ideal.

Cryptocorynes and Java ferns are two of the best leafy plants that grow just fine in low light environments like this one. Anubias is another great low light plant.

Try floating Anacharis along the upper levels of your tank to provide more shade for your secretive little loaches.

What Size Aquarium Do They Need?

A Kuhli Loach can be kept in a 20 gallon aquarium.

However, this fish thrives in a school of at least 5 so a 30 gallon aquarium will be needed.

Add around 6 gallons of water for each new loach you add to the tank.

Kuhli Loach Appearance

A Kuhli Loach looks like a tiny, colorful eel.

The most common variety is the Pangio kuhlii. They have a brown body with 6 to 10 bright yellow or orange bands. However there are other color forms including chocolate brown, reddish brown, silver, black and white, and even pink (more on this later).

This fish has a serpentine body that grows to about 4 inches long.

Their wide, fanlike caudal fin is the easiest one of their 6 fins to spot. They also have a short, rounded dorsal fin, a pelvic and anal fin, and a pair of pectoral fins just below their head.

You will notice they also have 8 barbels on their snout.

Interestingly this loach is considered a scaleless fish, but this is only partially true. They have thin scales along their body but their head is scale free (just like every species in the family Cobitidae).

Telling the difference between males and females is challenging.

Unlike most other fish, there is no difference in the colors of the two genders. However, males will have a thinner body and larger dorsal and pectoral fins.

Common Color Varieties

The color varieties of the Kuhli loach are actually different species. Here are a few of the ones you are most likely to find in an aquarium:

• Kuhli Loach (Pangio kuhlii): This is what most aquarists will call a Kuhli Loach. They are a muddy brown fish with bright yellow or orange bands along their body.
• Java Loach (Pangio semicincta): This species is endemic to the island of Java and has deep orange bands against a brown body.
• Black or Chocolate Kuhli (Pangio oblonga): Solid black or dark brown body.
• Cinnamon Kuhli (Pangio pangia): Reddish brown body.
• Silver or Eel Kuhli (Pangio anguillaris): This silver colored fish has a slightly longer and thinner body than other species. They can have black spots or speckles, or a black lateral line.
• Panda Kuhli: This fish does not yet have a species name. They are rare and have a black and silver color combination.
• Pangio filinaris: Iridescent pink or orange scales.

Black Kuhli Loach

Out of all of the different species and color varieties, the Black or Chocolate Kuhli is the most sought after.

Their solid black body really stands out when they are placed in a tank full of colorful tropical fish.

Black Kuhlis are bandless and come in shades from dark brown to black. They also have a small spot of purple near the snout on both sides. They have the same temperament and care requirements as any other Pangio species but may be a little difficult to find due to their high demand.

History and First Sighting

The Kuhli Loach was first discovered in Indonesia in 1846 by Valenciennes.

As time went by some discrepancy occurred regarding this species’ true identity when other similar species were discovered in the same area. It was not until 1993 that Kottelat published a key to distinguish Pangio kuhlii from the other Loaches in the Pangio genus. This helped to end the confusion between the species.

Kottelat described them as being slightly shorter than other species and having 6 to 10 yellow or orange bars and a dark spot over their caudal fin.

It was during this time too that this fish was first introduced to the aquarium trade.

Interest in the fish led to several mistakes in marketing, as certain species were mislabeled and sold as others.

These mistakes inspired further studies into the Pangio genus with the hopes of correcting the errors. By the early 2000s the distinguishing characteristics of all Kuhli Loach species became well known to keepers and suppliers.

Now the Pangio kuhlii is considered the true Kuhlii Loach. All other species are often marketed as color forms and variants.

Tank Mates

Lots of popular tropical freshwater fish can be kept with Kuhli Loaches.

They thrive with peaceful fish that inhabit the middle and upper levels of the tank.

Some good examples include Harlequin and Chili Rasbora, Tiger Barb, and Glass Catfish. Dwarf and Sparkling Gouramis would add colorful accents to this community.

Many of the most popular nano fish (such as Neon and Cardinal Tetras) can also be kept in a tank with a group of Kuhlis.

You can also include Zebra Danios too!

If you want to add other bottom dwellers to your tank then they should be a similar size to your loach.

The Glass Catfish is found alongside this loach in the wild and makes one of the best tank mates. Pleco and Cory Catfish also fit in just fine.

You should avoid keeping predatory fish of any size – this includes Bala and Rainbow Sharks. You should also steer clear of any fish that are large enough to eat your Kuhli Loaches. Clown Loaches and other rambunctious fish should be kept away too. The Clown Loach may look similar to the Kuhli Loach, but their personalities will clash in a big way.

Be careful too when adding shrimp or other small invertebrates to your community (more on this later).

Keeping Kuhli Loaches Together

These fish must be kept in a group in order to thrive.

When kept alone, they will spend most of their time hiding.

A group of 5 or 6 will interact with one another and scavenge in groups. You will often spot them congregating around food at the bottom of your tank.

They do not school or shoal but will remain close to one another when they come out to feed.

Bettas And Kuhli Loaches

You might be surprised to learn that Betta fish make good tank mates with Kuhli Loaches.

Since the Loach’s fins are so small, the Betta will not be tempted to nip or pick at them. And the Loach is so peaceful and passive that your Betta will not feel harassed by it.

As long as the Loach and the Betta are able to stay out of each other’s way, it is perfectly safe to keep the two together.

Shrimp And Kuhli Loaches

Kuhli Loaches can live with large and peaceful shrimp.

Good examples of these are the Cherry Shrimp and the Amano Shrimp. Very small shrimp (such as Grass or Ghost Shrimp) should be avoided because they will be eaten.

Just remember, if the shrimp is small enough to fit into the loach’s mouth, it will be eaten.

Breeding Kuhli Loaches

Unfortunately it is fairly difficult to breed Kuhli Loaches in an aquarium.

Very specific breeding conditions must be met.

If you want to try to breed your Loaches you should isolate a group of 6-8 in a separate breeding tank. Use a sponge filter and raise the water temperature to at least 79°F. The tank should be heavily planted because the fish will lay their eggs under the leaves. The lights should be dimmed at all hours of the day.

Feed your loaches at least 4 times a day and dim the lights to simulate nighttime and encourage them to eat.

Once these specific breeding conditions are met you might see your loaches piled together at the bottom of your tank – they are mating.

Pregnant females will appear visibly larger and rounder. If you look underneath a gravid female you will be able to see her ovaries. They will be so swollen that you can see them just under the abdomen.

During mating she will lay around 600 tiny eggs on the leaves of your plants. Remove the parents immediately once the eggs are laid.

It will take around 24 hours until the eggs will hatch.

Over the next 4 days they will keep their yolk sacs. Once they lose the yolk sac you should feed them infusoria and commercial fry foods.

It will take 4 months before your juveniles are ready to join the main tank and up to 2 years before they will be able to breed.

Species Summary Table

Should You Keep The Kuhli Loach? (Summary)

The Kuhli Loach is one seriously cool loach.

If you can handle their special care needs then they will make a fine addition to your tropical tank.

Their scaleless heads make them more delicate than other fish. Preventing injury and illness may be your biggest challenge in caring for these critters.

There are many different species to choose from and each comes with their own unique colors and patterns. They all have the same personality, diet and care requirements.

This secretive little critter may not be the most entertaining fish to add to your aquarium, but it does a fine job of livening up the bottom levels of the tank and cleaning up algae.

There is quite a lot that makes the Kuhli loach so coolie. In your experience, what is the best way to feed this Loach?