Kuhli loaches are one of my personal favorite tropical aquarium fish species, and for a good reason! They are peaceful, fun to watch and easy to keep, which means they’re a great choice for beginners and experienced aquarists.
Keep reading for everything you need to know about Kuhli loaches and keeping this striped bottom feeder in your own aquarium.
|Minimum tank size||20 gal (75 L, long)|
|Temperature||74-79 °F/23-26 °C|
Pangio kuhlii, Kuhli loach, Coolie loach (also sometimes referred to as Pangio acanthophthalmus)
Kuhli loach natural habitat
Slow moving forest streams and rivers in Indonesia. The water is often quite acidic, warm and stained with tannins. The substrate consists of sand and/or leaves.
The loaches live in larger groups and use the leaf litter to hide in. You won’t see them here during the day, though: they are nocturnal.
Kuhli loach appearance
Kuhli loaches have an eel- or snake-like appearance with a yellow body and dark brown vertical stripes. Like other loaches, they have barbels around the mouth, which are used to find food in the substrate.
With a maximum length of 10 cm (4 inches) they are one of the smaller loach species. Males and females are very difficult to tell apart, although when the females are carrying eggs they usually grow a bit larger and broader than the males.
Kuhli loach requirements
Because they stay relatively small, Kuhli loaches don’t need a very large aquarium. Floor space is more important than the amount of water, as loaches mostly stay on the bottom of the tank. This means it’s a good idea to go for a longer, rectangular aquarium than a higher one. An 31.5″/80 cm aquarium is a good place to start. Sand substrate is preferred, as these fish like to use their barbels to sift through the substrate, which isn’t possible with gravel.
In the wild, Kuhlis live in big groups in darker habitats with plenty of places to hide. A very exposed environment without hiding places and other Kuhlis will stress them out. Try to prevent this! Keep your Kuhlis in groups of at least 5. If you do keep them alone, you likely won’t see them much.
Because Kuhlis prefer to hide with the group for part of the day it’s very important to give them enough places to do so. This doesn’t have to be complicated: a few shrimp caves can be enough to keep them happy. You can also use Indian almond leaves to create natural, dark water.
Remember that as with most fish the rule is that the more hiding places you supply, the less they will use them. If the environment is very open your Kuhlis stay in hiding more because they don’t feel it’s safe enough to come out.
Kuhlis are very peaceful, so be sure to go for calm tankmates. Aggressive fish can scare and possibly harm them, causing them to go into hiding and disappear for extended periods of time. Not very fun.
Kuhli loach diet
Mostly carnivorous. Kuhlis usually accept pellets and flakes, but their diet should also be supplemented with frozen and ideally live foods like blood worms, mosquito larvae and brine shrimp.
Regular fish foods usually don’t contain all the nutrients they need, so go for some variety! Also be sure to feed foods that are designed to sink, like loach pellets, because your Kuhlis may not be able to find floating foods.
Having trouble feeding your Kuhlis? Try feeding after you’ve turned off the tank lights. As we’ve discussed before this species is nocturnal and might not come out to eat if they think it’s still daytime. This especially applies if you recently introduced your Kuhli loaches and they’re still skittish.
Kuhli loach behavior
Kuhlis are one of my favorite fish species not only because of their adorable looks, but also because of their behavior. They are peaceful towards their own species and others, which makes them suitable for even the most calm setups.
Any Kuhli keeper will tell you that the most fun part of keeping them, though, is watching them interact with each other. They love to share hiding places with as many other Kuhlis as possible, which means you’ll often see ‘piles’ of them forming in a tiny spot.
No clue where your Kuhlis have gone? No need to worry just yet. These fish are known for going into hiding for extended periods of time if you’ve provided the soft substrate and hiding places they need. This is especially likely to happen if you’ve just introduced them into the tank. Give them some time and they’ll come out in the open more often.
Breeding kuhli loaches
I have not been able to find very clear reports of Kuhli breeding. It is often recommended to do a water change with slightly cooler water to stimulate spawning behavior, after which the eggs are attached to plants and driftwood in the tank.
The fry will feed off tiny food particles at first, and you can start supplementing their diet with microworms and eventually bigger foods. The water should be kept clean and water values should be stable. If you have a more detailed breeding report, let me know!
The video below shows Kuhli breeding behavior. Kuhli loaches are partly nocturnal, hence the red night lights.
If you’re looking for a fun, interesting and relatively easy to keep fish species for a peaceful community aquarium, I would totally recommend considering Kuhli loaches. If kept correctly, they are a great addition to the community.
If you have any questions about Kuhli loaches or want to share your experiences, leave a comment below. Happy fishkeeping!
Cover photo: Nathalie Nyman