8 Facts About the Fascinating Loach Fish


There are over 1,200 species of loach fish. They are found in central and southern Asia, Europe and Africa in ponds and streams. The loach fish’s appearance varies drastically from one species to the next. In this blog post, we are going to learn 7 interesting facts about the loach fish.

1. What Do Loach Fish Look Like?

The loach fish varies in body type, shape and coloration. For example, the Reticulated Hillstream Loach looks like this:

Frank M. Greco, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons

as compared to the Clown Loach which looks like this:

ML5 at English Wikipedia, Public domain, via Wikimedia Commons

to the Dojo Loach which looks like this:

While they may vary greatly from species to species, they are all a primarily bottom dwelling species. Their bottom turned mouth helps them to eat off of the substrate of their environment. Some are long and slender like the Dojo Loach while others are bulky and more “fish like” like the Clown Loach.

2. What Do Loach Fish Eat?

The loach fish is an opportunistic scavenger. Unless there is an opportunity to eat another, smaller fish, the loach fish tends to stick to worms, small crustaceans and organic material. In the aquarium, the loach fish will accept flake foods (if the other fish don’t consume them first), sinking pellets, live worms, live brine shrimp, small snails, plant matter, freeze dried tubifex worms, frozen brine shrimp, live and frozen blood worms.

3. How to Loach Fish Breed?

Since there are over 1,200 species of loach fish, breeding specifics will vary from species to species. With that said, let’s take a look at the kuhli loach’s breeding process as our example. This species is communal and will pair off in order to spawn.

The original uploader was Marrabbio2 at Italian Wikipedia., CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons

Once the eggs are fertilized, the female will deposit them underneath floating plants. In about 24 hours, the eggs will hatch and the fry (baby fish) will swim out of their eggs and into their environment. The fry will then scavenge for food such as small crustaceans like the brine shrimp.

After about 6 weeks, the fry will reach ~1 inch in length. The smallest baby kuhli loaches are available for purchase in the aquarium trade at 2 inches in length on average. The breeding process in captivity is known to be pretty difficult and requires a group of at least 8 kuhli loaches in order to get a pair or two.

4. Are Loach Fish Aggressive?

Loach fish are labeled as “semi-aggressive” which is based on having just one in your aquarium. If you have a group of six or more, the aggression will be less. Most of the aggression that is reported by aquarium hobbyists seem to occur during spawning time and if there is not a group of the same species in their aquarium. Other than that, this species is generally regarded as a peaceful scavenger.

5. Are Loach Fish Community Fish?

Generally yes, however, loaches from the Botiidae family are known to pick on smaller and slower swimming fish in a community tank – whether their is a group of them or not. Members of the Botiidae family are the:

Clown Loach

The original uploader was Marrabbio2 at Italian Wikipedia., CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons

Red-finned Loach

Astellar87, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

Skunk Loach

I, Lerdsuwa, CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons

If you are thinking about adding some loach fish to your community aquarium, be sure to do thorough research on that specific species and their aggression factors before adding them to your aquarium. Also please keep in mind their maximum growth rates as some can get quite large – and the aquarium space, filtration, etc. that will be needed in order for them to thrive.

6. What Are Loach Fish Good For in an Aquarium?

Loach fish are known to be excellent scavengers and a great addition to a freshwater clean up crew. They’ll eat organic matter on and within the surface (if you have soil or another form of soft substrate) of your substrate. They will also take care of uneaten food as well as keep the populations of small crustaceans in check so that they do not over run your aquarium.

They still need a good balanced diet so be sure to feed them some freeze dried, frozen or pellet types of foods as well as any of the foods that we covered in fact number 2.

7. How Smart Are Loach Fish?

The loach fish is known for being a very intelligent and social species. One of the most popular loach species in the freshwater aquarium hobby, the clown loach, is known to be extremely friendly, intelligent and social.

8. How Long Do Loach Fish Live?

On average loach fish can live up to 10 years of age depending on the specific species.

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