At PetMeTwice, we hold a special fondness for the Kuhli loach, a type of tropical fish. This calm freshwater dweller enjoys solitude but also appreciates companionship, captivating many fish lovers with its eel-like look. Using our most trusted sources, we have created this guide to give you all the vital details about Kuhli Loach, including advice on keeping them happy and healthy.
Article Summary
- Kuhli loaches, known for their peaceful nature, thrive as freshwater tankmates, showing increased sociability in groups of 5 or more, and they coexist well with tetras, danios, rasboras, and gouramis.
- Omnivorous Kuhli loaches, thriving on a diet of commercial fish flakes and high-protein fare, should be fed once a day adhering to the three-minute rule.
- Successfully breeding Kuhli loaches is challenging, necessitating the recreation of their native spawning environment in a tank with shallow water, floating plants, and subdued lighting.
Species Overview
| Common names: | Kuhli loach, leopard loach, coolie loach |
| Scientific names: | Pangio kuhlii |
| Species: | P. kuhli |
| Lifespan: | 10 yrs |
| Family: | Cobitidae |
| Genus: | Pangio |
| Distribution: | Southeast Asia |
| Size: | 3-4 in |
| Color: | Green, brown, black |
| Diet: | Omnivore |
| Temperament: | Peaceful |
| Minimum tank size: | 20 gal |
| Place in the tank: | Bottom |
| Breeding: | Difficult |
Kuhli loach History and Background
Previously a food source, the kuhli loach has come a long way to being one of the most popular fish in the aquarium industry. First described in 1973 by Sterba, this fish goes by many names- such as leopard loach and coolie loach- but is officially known as Pangio kuhlii. Read on to learn more about this fish and where it comes from.
What is a kuhli loach?
A freshwater fish that lives in tropical areas, the Kuhli loach used to be a food source for Indonesians prior to the mid 19th century. After which they started to gain popularity in the aquarium hobby and became a staple aquarium fish.
Where did the kuhli loach come from?
Wild kuhli loaches originated in Southeast Asia, mainly in areas such as Malaysia, Borneo, and Thailand.
Kuhli loach Appearance
The interesting thing about these fish is they look like miniature eels. Fortunately they possess none of their look alike’s more shocking characteristics.
What do kuhli loach look like?
Kuhli loaches look abnormal for aquarium fish. They have an eel like body with small fins and an unclear lateral line. The dorsal fin, while visible, is further down their body (close to the tail) than other fish. They have larger pectoral fins and four pairs of barbels to help them navigate their natural habitat.
Most kuhli loaches are multi-colored and have a lighter base color on top of which are many black or dark brown stripes (10-15). Some aquarists say this makes them look like a tiger, others have deemed them the leopard loach. When the tank is heavily planted, it’s almost like they are in an aquatic jungle.
While known as a non aggressive fish, kuhli loaches have a unique defense mechanism of sharp spine below their eye. When threatened, or stressed these spines can pop out making sure that if they do get eaten they damage their predator.
How to tell the gender of a kuhli loach
The easiest way to differentiate between male and female kuhli loaches is by looking at their pectoral fins. Males have larger pectoral fins as well as having a thicker body around the dorsal area.
Kuhli loach Variety
Black Kuhli Loach
Instead of having a lighter base color and dark stripes this fish is completely black. There’s nothing else different about this eel shaped fish. Many aquarists enjoy the unusual coloring of black kuhli loaches.
Silver kuhli loach
Many loaches with this color variation don’t have an obvious dark stripe pattern. In fact, their body is a lighter hue with some light brown or yellowish stripes around their body.
Most popular variety
The black kuhli loach is the most popular species as it is not a color variation often seen in the fish’s natural habitat and is sought after by aquarists who want a unique color arrangement in their aquarium.
How big does a kuhli loach get?
Average Kuhli loach size in their natural habitat is around 5 inches. In a home aquarium adult fish generally grow to be 3 to 4 inches.
How fast do kuhli loach grow?
Kuhli loaches are fairly slow growing and will reach mature size in roughly 2 years. While most will stay closer to three inches, kuhli loaches can grow up to four inches when fed a nutritional diet and kept in a pristine environment.
Kuhli loach Temperament and Tankmates
A peaceful species, these fish can be housed with almost any peaceful freshwater fish of similar size, and get along especially well with those that swim in the mid or upper levels of the tank.
Kuhli loach Behavior & Temperament
Kuhli loaches are peaceful fish and tend to keep to themselves at the bottom of the tank. They are ideal tank mates as they get along with most freshwater fish species.
Do kuhli loaches need to be in groups?
Kuhli loaches are not schooling fish so it’s not necessary to have more than one. However, they do tend to be more outgoing when they are with their own species, or similar fish species so it’s not a horrible idea to keep them in groups.
How many kuhli loach to keep?
A group size of 5 or more depending on your tank size is ideal.
Can you keep a single Kuhli Loach?
While you can keep a single kuhli loach you should expect it to be very shy and spend the majority of its time burrowing or hiding.
What fish can live with kuhli loach?
Good tank mates for kuhli loaches are peaceful fish of roughly the same size that spend a majority of their time in the upper ⅔’s of the tank. Because Kuhli loaches spend all of their time at the bottom of the tank, upper level tank mates will keep to themselves and not stress your loach out.
- Other kuhli loaches – while loaches aren’t exactly schooling fish (meaning you don’t necessarily need to keep them in groups) they get along well with others of their kind.
- Tetras-a small, non aggressive fish that will spend a majority of their time in the upper and middle levels of the tank.
- Danios – keeping your loach in a home with danios will prove to be a delightful experience guaranteeing lots of colors and high activity levels.
- Rasboras – a mid-sized species that will do well with other peaceful fish.
- Gouramis-an excellent option to add activity to upper levels of your tank, gouramis are calm and peaceful.
Compatible Tank Mates
Tank mates to avoid
- Cichlids – a normally aggressive and territorial species they will see your kuhli as dinner.
- Tiger barbs – generally territorial these fish don’t do well with loaches. Think of it like the jungle, tigers and leopards don’t get along and neither do tiger barbs and the leopard loach.
- Betta fish – an aggressive fish that will likely attack your kuhli despite them living in separate parts of the tank.
- Goldfish – though not particularly aggressive goldfish will rapidly foul up the water quality of your tank, you should avoid them if you’re not ready for an intense maintenance schedule.
- Angelfish – Known for their aggression, angelfish won’t make a good tank mate for your Kuhli.
Kuhli loach Tank Requirements
The tank setup for this species is not difficult, the most important thing is being able to maintain stable water parameters as this fish is sensitive to change.
Water Parameters
| Tank Size: | >20 gal |
| Water Type: | Freshwater |
| Water Temperature: | 73-83 |
| Water pH: | 5.5-6.5 |
| Water hardness: | <5 dGH |
Tank setup:
What kind of substrate do kuhli loach need?
As this species likes to burrow, it is recommended that you choose soft and fine substrate. Large substrate or those with a jagged edge can lead to injury for your fish. Sand or fine gravel is the best choice.
Do I need a Filter?
Yes, an aquarium filter is absolutely necessary for proper kuhli loach care and will help reduce the amount of water changes you will have to perform.
Should I get a Pump?
A pump is not necessary for the kuhli loach as it is used to slow flowing environments. However, if you decide to have a heavily planted tank you should add a pump to make sure the water is fully circulating.
Do I need a Water heater?
Yes, as a tropical fish species you will need a fish tank heater to maintain a stable temperature range and provide proper parameters for kuhli loach care.
What kind of lighting do I need?
Average tank lights such as 40 watt bulbs are sufficient for this species. They don’t like a lot of light and if you add too many aquarium lights they will spend a majority of their time burrowed under the sand.
Tank Type For Kuhli Loach
Kuhli loaches should be housed in a freshwater aquarium that has dense vegetation, caves, and places for it to hide. Driftwood, large leafed plants, and commercial tank decor is beneficial to have as it provides them an escape for others.
Additionally, keeping your loach in shallow water environments such as a paludarium is a good idea as it would replicate their natural environment.
What size tank for kuhli loach
Kuhli loaches need at least a 20 gallon tank, with an additional 5 gallons added for each time you add more kuhli loaches.
Filter Type For Kuhli Loach
You should choose which filter works best for your tank and its needs. However, you should note that this fish is well known for getting itself stuck in the inlet tube of filters. An undergravel filter where the inlet tube is securely covered would be the best for this fish.
TIP
Covering the inlet with fine mesh is an excellent way to make sure nothing can get stuck.
Kuhli loach Diet and Health
Feeding your fish a healthy, high quality diet will not only improve their lifespan, but will also prevent diseases, give them more energy, and brighten their natural colors.
What do kuhli loach eat
Wild kuhli loaches eat plant matter, small crustaceans (like tiny shrimp), and young fish or fish eggs. They are considered to be omnivores and scavengers and aren’t very picky eaters.
TIP
A scavenger is an animal that searches for their food by sifting through sand or other substrate. This is different from a predator which is an animal actively hunting for prey.
What to feed kuhli loach?
A majority of your kuhli loaches diet should come from commercial fish flakes. Specifically formulated flakes for loaches will ensure that they are receiving the proper minerals and vitamins that might be missing in live foods.
In your fish tank you should feed your kuhli loaches a high protein diet. This can include frozen, freeze dried or live foods. Live food such as brine shrimp, water fleas (daphnia) or frozen bloodworms both make for a high quality meal.
How often to feed kuhli loach?
Plan on feeding your kuhli loach once a day. You can either coordinate feeding times with the other fish in your freshwater aquarium or drop food into the tank in the morning and allow your fish to graze throughout the day.
If allowing fish to graze on food throughout the day be sure to remove all uneaten food each evening to keep your tank clean and your water quality pristine.
How much to feed kuhli loach?
Feed your kuhli loaches according to the three minute rule. This is the most effective method to ensure that your loach is receiving enough to eat while not overeating. While this fish isn’t prone to overeating you should still observe to see if they are bullying others for food, or experiencing any gastrointestinal issues like constipation or bloating.
Common diseases of kuhli loach?
Kuhli loach care includes lots of disease prevention as they don’t have hard scales to protect them from bacteria, parasites, and fungi.
Ich
One of the most common diseases for these fish is ich, as they are particularly sensitive to minute water changes. Ich, commonly known as the white spot disease, presents itself with white fuzzy patches along the body and fins of a fish. It is a bacterial disease and can be treated with broad spectrum antibiotics.
Flukes
Flukes are a type of parasite that usually attaches themselves to the gills of fish. You might notice these small creatures on your fish’s gills or you might notice other symptoms such as the fish gasping for air, scraping their gills against structures, or ulcers. Treatments include salt baths, and anti-parasitic medication.
How long do kuhli loach live?
The average kuhli loach lifespan is ten years in a fish tank. This is assuming that the water parameters are in pristine condition and that dietary needs are met.
Kuhli loach Breeding
Breeding kuhli loaches in captivity is difficult and not done often. Read on to learn more about how expert fish keepers encourage these fish to reproduce.
Can you breed a kuhli loach?
While not impossible to breed kuhli loaches it is very difficult and requires replicating their native spawning environments closely.
How to breed a kuhli loach?
The first step when intending to breed this species is to set up their breeding tank. These fish’s natural spawning habitat is in shallow water with thick vegetation. The breeding tank should have a water level that is only a few inches deep and lots of floating plants. Additionally, some people have reported more success with low lighting and raising the pH to 6.5.
Feed your mating pair a high protein diet. Once the female spawns, immediately remove the adult kuhli loaches. Eggs will take roughly 1 day to hatch, and another two to three days to become free swimming. Once they are free swimming you can feed the fry freshly hatched brine shrimp and infusoria. Remember that the adult fish’s mouth is small, meaning that the fry likely won’t be able to eat larger food until a month or two after hatching.
How to tell if a kuhli loach is pregnant
Pregnant kuhli loaches are fairly obvious, mainly because the eggs are bright green contrasted against the dark brown undersides of the fish.
What do kuhli loach eggs look like
Kuhli loaches have bright green eggs, which helps them remain camouflage on the undersides of plant leaves. Females will lay eggs in large clumps so the easiest way to find them is to look for a pile on the underside of the floating plants.
Kuhli loach FAQS
Are Kuhli Loaches aggressive?
No, this is a low maintenance fish and very peaceful. Your kuhli loaches love spending the day exploring the bottom of your tank looking for their next snack.
Do kuhli loaches eat other fish?
No, these fish are not predators and make great tank mates because of the fact that they will leave other fish alone.
Do Kuhli Loaches eat shrimp?
While it is unlikely that your kuhli loach will actively seek out and eat shrimp they might accidentally ingest a tiny shrimp as they search for food along the bottom of the tank. For more food and diet info regarding this fish check out Chapter 5 above.
Do Kuhli Loaches eat snails?
No, kuhli loaches eat snails is just a myth. These fish prefer to scavenge and won’t actively hunt prey. Additionally, the snails shell is too large to fit in the fish mouth.
Do Kuhli Loaches clean the tank?
Yes, because these fish live at the bottom of the tank they will eat any organic matter or algae that is on the bottom. However, this is no excuse to not clean and maintain your aquarium regularly.
Do Kuhli Loaches hide in gravel?
Yes, these fish like to burrow into substrate which is one of the reasons why it is important to choose a soft or fine substrate.
Do Kuhli Loaches play dead?
While these fish don’t play possum, it is common for them to go “missing” because they’ve buried themselves in the substrate for a few hours.
Why is my kuhli loach swimming frantically
Likely a sudden noise or movement scared your fish and they are trying to find a safe spot. One way to tell if they are stressed is by looking at their eyes and seeing if their spines are out. If not, it’s safe to say that these little fish just got a case of the zoomies.
Why is my kuhli loach swimming up and down
Your fish swimming vertically in the tank is often a sign of disease or stress. Either something at the bottom of the tank is scaring your fish or they might have swim bladder disease or a parasite which doesn’t allow them to control their buoyancy. The first step in solving the problem is performing a water test and acting based on the results.
Why is my kuhli loach swimming in circles
There are a few different theories as to why your fish might be swimming in circles.
- Lack of food – your fish might be trying to search for extra food in the area because it’s not getting enough nutrition from its daily feeding.
- Poor water quality – these fish can often suffer from maladies stemming from poor water quality. Put the affected fish in a care tank and continue to monitor to see if it improves
- Weather changes – some long time keepers of this species claim that they will swim in circles when it’s raining or the weather starts to cool. I’ve never seen research on this subject but it could be possible.
Why is my kuhli loach pale?
Many factors can affect a fish’s color lightening, old age, disease, or response to stress are just a few of the possible causes of this odd phenomena. The best course of action is to keep a close eye on your fish and perform a water quality test to try to deduce the problem. With close observation you might find that a tank mate is being a bully, or your fish isn’t eating.
Is the kuhli loach for you?
If you think the coolie loach is pretty cool we couldn’t agree more. This freshwater fish is an excellent addition to the bottom of your tank and will provide hours of entertainment with its burrowing and high activity levels.
Conclusion
Whether you’re looking for an exotic fish that looks like an eel, or hoping for another bottom feeder to add to your tank clean up crew, the kuhli loach should be your next purchase.