Kuhli loach (Pangio kuhlii)

Kuhli loach (lat. Pangio kuhlii) is a fish kind of Cobitidae family. This is a peaceful ground fish that is more active in the evening and at night. This is a bright and easy to keep tank fish. As for its disadvantages, these can be its nocturnal habits and wariness. As a result, you may not see it in a tank during the day. Further in the article, you’ll find out how to keep, feed, breed, and choose tank mates for kuhli loach.

Habitat in the wild

The fish received its specific name from the French ichthyologist Achille Valenciennes by German zoologist Heinrich Kuhl (1797 – 1821). Its initial Latin name was Acanthophthalmus kuhlii, and recently it has been changed to Pangio kuhlii.

Fish habitat is in South-West Asia and India. The fish also inhabits Sumatra, Singapore, Malaysia, Java, and Borneo Islands. In the wild inhabits in slow forest streams with a 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 snags in the water.

Among such a number of covers, loach feels perfect. In the wild, the fish can be seen in small groups; however, it’s not a schooling fish.

Difficulties in keeping

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

The kuhli loach 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.

Fish is an “owl”; therefore, its activity can be observed during twilights, and at night, it is always hiding. The fish can hardly be seen in the daytime, especially when 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, fish can also be 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.

Description

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

The fish has an albino morph that was bred artificially, and it can’t be seen in the wild. Since it is a night fish, the species with albino coloring die rather quickly because they are quite noticeable on the bottom.

Underneath its eyes, the fish has a flexible recurved spine that serves as protective means against predators. When trying to catch the loach, these spines strike out and dig into the attacker’s mouth. Usually, this is enough to make it spit out such an unpleasant prey and not to make any further attempts to eat it. These spines produce an illusion of the eye outline’s absence. For this reason, the fish received its name «Acanthophthalmus,» which literally means ‘a torn eye.’

Kuhli loach, intestinal respiration is peculiar to this loach like other representatives of the family. They can swallow air bubbles that, when getting to some specific areas of their intestinal tract, oxygenate the blood.

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

Care and keeping in a tank

Scientific NamePangio kuhlii, Acanthophthalmus kuhlii
FamilyCobitidae
Common NameKuhli loach, coolie loach, khuli loach, kuhli fish, striped kuhli loach
Ease of keepingEasy
Lifespan10 years and more
Tank size30 liters (6 gallons) and more
TemperamentPeaceful
Tank typeCommunity of fishes
DietOmnivorous bottom feeder
Temperature75 – 86 °F (24 – 30 °C)
pH5.5-6.5
Water hardness5–15 dGH
SizeUp to 20 cm (8 in), usual 17 cm (6.69 inch)

Kuhli loaches are lively and undemanding fish, but their nocturnal habits and absence of scales impose some constraints upon their keeping conditions. It is crucial to provide the fish with clean water and stable water parameters as well as efficient filtration and aeration.

Once a week, you should renew the tank water (25-30% of the total tank volume). At that, you should be attentive to make sure that the fish isn’t sucked in by the water flow when siphoning the substrate since the fish can hide in quite unexpected places.

Tank size

The tank should be moderately sized with soft, a little acidic water, and moderately lighted. Since kuhli loaches are nocturnal fish, bright tank lighting will not be appropriate here. They feel more comfortable provided with scattered dim light.

It is groundfish, so not the tank size is determining, but the square of its bottom. The fish grows up to 10 cm (4 in) long, so the desirable capacity for one fish is about 6 gallons (30 liters). The fish feels better in a school of 5-6 fishes, so after you do some maths, it’s clear what tank’s capacity is required.

When atmospheric pressure decreases, kuhli loaches become anxious and start swimming in circles in the tank, sometimes jumping out of the water. You’ll need some kind of lid or glass cover for the tank to make sure the fish won’t jump out of the tank.

Water parameters

As for the tank water composition, kuhli loaches are rather undemanding in this respect.

The following water parameters will do: temperature 75 – 86 °F (24 – 30 °C), general hardness dGH from 5 to 15° and pH: 5.5-6.5. Proper filtration is required, and regular water renews (15-20% weekly).

Tank setup: decorations and plants

Several shelters should definitely be in a tank, something like snags or caverns, where the fish will hide during the day. Put several snags with narrow holes or 3-4 ceramic tubes or coconut shells with small holes in them. These will serve as shelters for the fish.

The latter is quite timid. Thus any abrupt movement near the tank makes it hide quickly among thick plants, cracked stones, or snags.

The tank should be thickly planted because the kuhli loach likes spending day time in the plants. The substrate should be small-grained without sharp edges, and sand is an ideal substrate. The fish can dig into the substrate to dig blood worms out of it. If the tank has a sandy bottom, they can dig into the sand completely, which won’t happen in gravel bottom, even with small-grained gravel.

Since the fish is a bottom dweller, some stones should be quite smooth because their sharp edges and the sheared surface may damage the loach skin.

You should put some grating with small holes on filters input and output to ensure that the fish won’t get inside it. You also should keep in mind some slits in the filter or other holes where the fish can kill itself. Since it’s very curious, it’ll swim everywhere. Though fish spends most of its time on the tank bottom, it’s desirable to cover the tank from the top because the fish can easily get out of it through the tiniest slits.

When catching the loach, don’t forget about its spines underneath the eyes. They can’t do any serious damage, but the prick is quite noticeable. Besides, they hook to the scoop-net with these spines and often get stuck in it.

Catching kuhli loach in a tank is no easy feat. The fish is rather quick, and it’ll use every chance to hide and slip through the net.

When taken out of the water, loaches can make funny pulsed squeak sounds.

Feeding

Since it is a euryphagous fish, 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 kuhli loach likes the following live feed: blood worm, tubifex, brine shrimp, daphnia, etc.

Besides, it’s not a problem for kuhli loach if a tubifex or blood worm gets into the substrate because the fish easily finds them and digs them out. The fish is irreplaceable if you feed other fishes with live feed, and some of it falls on a tank bottom and then spoils.

However, feeding with live food has several serious dangers in it. You can easily get some infection or invaders into the tank. Many aquarists feed their fish with frozen food, which is much safer than the live one.

The fish diet should on 20 % consist of vegetable food. Thus you should additionally feed them with food with high spirulina content. You may use chips, but the most convenient shape, in this case, is pellets that drown. They quickly get to the tank bottom and are available for eating for a long time.

To ensure that loaches get their food, you should drop it where they prefer staying in the tank, and this should be done shortly before you turn off the lights. This way, you can be sure the fish won’t starve.

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 crush the shell.

Tank mates

Kuhli loaches 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 similar size. They pick up the leftovers that other fishes haven’t eaten from the tank bottom.

They can live together with any small peaceful tank mates dwelling in middle and upper water layers. Corydoras, guppies, betta, neon tetra, angelfish are perfect loach tank mates. You can also put cherry shrimp into the tank, and the fish won’t do any harm to crustaceans.

However, some fishes are not recommended to put in one tank with loaches. Kuhli loach should be in one tank with cichlids.

First of all, these are large cichlids (oscar fish, green terror, flowerhorn, red terror cichlid). These predators will treat loaches as food. Goldfishes mostly are bottom diggers, and they’ll disturb loaches; besides, they require essentially lower tank water temperature. Territory-dependent bottom-dwelling fish such as red-tailed black sharks also aren’t the best tank mates for loaches, and they may harm them.

Gender differences: male vs female

Gender dimorphism is feebly marked, so without any practical experience, it’s quite challenging to see between the fish male and female. Males are a bit smaller. Their body is narrower, and the abdomen is almost smooth. The adult female’s body is almost cylindrical; their abdomen is a bit rounded, some swelling near its anus can be observed.

Females are thicker, which can be noticed from above. If the female has eggs in her, they are seen as elongated greenish spots on her abdomen. The male has a pectoral fin whose first ray is thickened and branched.

Breeding

In the wild, the fish spawning period is in December-January. Specialists mention imitation of the rainy season beginning as one of the means to stimulate loaches spawning (it’s desirable to combine it with atmospheric pressure wave).

You should make the tank water softer, decrease its temperature, reduce the lighting intensity and duration. There is no verifiable information if all these factors really work (each by itself or all together).

Cases of successful kuhli loach 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 are 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 30 liters capacity (water height 15-20 cm), and a separation net should be put in it.

For spawning, take the fish females with the 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 be removed from the tank right after spawning.

The 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, striped juveniles become about 1 cm long and become striped. They become reproductive at the age of 8-12 months.