Kuhli loach (Pangio kuhlii)

Kuhli loaches (Pangio kuhlii, earlier named as Acanthophthalmus kuhlii) also named as coolie loach, Leopard Loach is a peaceful ground fish which is more active in the evening and at night.

Kuhli fish is an “owl” therefore it’s activity can be observed during twilights and at night, it is always hiding. The fish can hardly be seen at day time, especially when it’s kept in a tank alone, however it’s not impossible, if one watches the fish for some time.

If several fishes are kept in a tank they become more active at day, maybe due to the appearance of food rivalry.

A group of dozen kuhli loaches will have more active behavior and it’ll be more close to their behavior in the wild, nevertheless Acanthophthalmus can be also kept alone in a tank.

The fish is rather enduring and it can live in a tank for quite a long time and it won’t suffer because of the lack of company.

Also fishes from loaches family are known as weather forecasting fishes – they react on atmospheric pressure change and start going crazy, swimming actively along the tank walls or in circles.


Habitat in the wild

Kuhli loach habitat (Acanthophthalmus Kuhlii) is in South-West Asia and India. The fish also inhabits in Sumatra, Singapore, Malaysia, Java and Borneo Islands.

In the wild inhabits in slow forest streams with soft muddy bottom, the stream is usually flowing in the shade of thick tropical flora, where the light doesn’t get through and with a lot of fallen leaves and snags in the water. Among such a number of covers feels perfect.

In the wild the fish can be seen in small groups however it’s not a schooling fish.


Acanthophthalmus Kuhlii is a small striped loach that will grow to be about 8-12 cm (4-5 in) long, however in a tank it won’t be longer than 8 cm. Lifespan is about 10 years, although it may be longer.

The fish body is pink yellow with 12-17 wide dark stripes. There are three pairs of barbels (whisker-like) on its head. The dorsal is placed very close to the anal fin, they are almost on the same line. Also the fish has an albino morph that was bred artificially and it can’t be seen in the wild.

Since Acanthophthalmus is a night fish the species with albino coloring die rather quickly because they are quite noticeable on the bottom.

Difficulties in keeping

Care is simple and easy. What makes the fish different from the others is that it doesn’t have scales, which makes Acanthophthalmus very sensitive to medicines, chemical combinations and it has to be taken into account when treating the fish or putting some chemical products into a tank.

The fish likes clean and well aerated water, and frequents water renews. It’s necessary to siphonate the bottom while changing the water to remove the litter, since loach fish as a ground one suffers the most from ammonia and nitrates on the bottom.


Since Acanthophthalmus is an euryphagous fish, it a tank it eats all types of live and frozen feed, different tablets, granules, pellets. The main thing is the feed should fall on the bottom and not being eaten by other fishes.

The fish likes the following live feed: blood worm, tubifex, brine shrimp, daphnia etc. Besides it’s not a problem for Acanthophthalmus if a tubifex or blood worm gets into the substrate, because the fish easily finds them and digs them out.

The fish is irreplaceable is you feed other fishes with live feed and some of it falls on a tank bottom and then spoils. Also loaches can feed on snails, but rather seldom. The fish puts its head into the snail’s shell and tries to eat the snail simultaneously hitting it on the ground to crash the shell.

Keeping in a tank

Kuhli loach tank should be moderately sized with soft (0 – 5 dGH), a little acidic water (ph: 5.5-6.5 ) and moderately lighted. Is a ground fish, so not the tank size is determining, but the square of its bottom.

The fish grows up to 9-10 cm long, so the desirable capacity for one fish is about 50 liters. The fish feels better in a school of 5-6 fishes, so after you do some maths it’s clear what capacity of the tank is required.

Several covers should definitely be in a tank, something like snags or caverns, where the fish will hide during the day. Check if the tank has any places where the fish can get and stuck there, and change the design there. We are also talking about some cracks in the filter or other holes where the fish can kill itself.

Since it’s very curious it’ll swim everywhere. Though they spends most of its time on the tank bottom, still it’s desirable to cover the tank from top, because the fish can easily get out of it through the tiniest cracks.

Tank should be thickly planted, because the fish likes spending day time in the plants. The substrate should be small grained without sharp edges, sand is an ideal substrate. The fish can dig into the substrate to dig out blood worms out of it.

Scientific NamePangio kuhli, Acanthophthalmus kuhlii
Common NameKuhli loach, Coolie Loach, Leopard Eel, Prickly Eye, Khuli Loach
Tank size10 gallons (50L) and more
DietOmnivorous bottom feeder
Temperature75 – 86 °F (24 – 30 °C)
Size2 ¾ inches (7 cm) – 4 inches (10 cm)

Compatibility with other fishes

Don’t show schooling behavior, but they feel more comfortable in a group of 4-5 or more fishes. If there are 1-2 species in a tank they behave rather reticent and get out of their covers only at night.

The fish is completely peaceful, compatible with any fishes of alike size, white cloud mountain minnow, harlequin rasbora, otocinclus catfish, red-tailed black shark, betta and shrimps like red cherry shrimp. They pick up the leftovers that other fishes haven’t eaten from the tank bottom.

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Sex differences

Females are thicker, that can be noticed from above. If the female fish has eggs in her, they are seen as greenish elongated spot on her abdomen.

The male has pectoral fin which first ray is thickened and branched.


Cases of successful acanthophthalmus kuhlii breeding in a tank are rather seldom. Sometimes at good tank conditions the fish may spawn in a community tank, but the eggs are left unfertilized and soon they eaten by the parents or other fishes.

Generally in tank conditions the fish spawning is stimulated by injections of gonadotrophin and spawning starts in 6-8 hours. As a spawning pond you’ll need a tank of 10 gallons capacity (water height 15-20 cm) and a separation net should be put in it.

For spawning take the fish females with noticeably rounded abdomen, 2 male fish and 1 female – is the best ratio. The male haunts the female. Then he cuddles his head to hers and it looks like he is holding her with his pectoral fin. The fish couple moves rather fast around the bottom swimming to the water surface where the female spawns.

Small light green eggs stick to the plants leaves or fall on the tank bottom. One loach female can lay about 500-700 eggs. The fish parent should removed from the tank right after spawning. Incubation time of the eggs lasts about 1 day, then small green ich fry appears.

In 4 days they start swimming and feeding. Loach fish juveniles can be fed with infusorians, rotifers, brine shrimp nauplii or tubifex cut in small pieces. In a month juveniles become about 1 cm long and become striped. Acanthophthalmus becomes reproductive at the age of 8-12 month.