Clown Loach: Species Overview

Category: Loach

Common Names: Clown Loach

Scientific Name: Botia macracantha

Family: Cobitidae

Minimum Tank Size: 75 Gallons

Care Level: Moderate

Temperament: Semi-Aggressive

Max Size: 12 Inches

Temperature: 74-84 F

pH: 6.0-7.5

Tank Level: Bottom

Colors: Black, Yellow, Red, Orange

Diet: Omnivore

Breeding: Difficult

Clown Loach on Gravel from the Side

Clown Loach Species Overview

The clown loach is a reasonably low-maintenance species popular with fish keepers, regardless of their experience level. With bright colors, a distinctive overall appearance, and a generally peaceful temperament, the clown loach is one of the staples of the freshwater aquarium in much of the world.

Regardless of your skill level, you can master the art of keeping these hardy fish in your tank.

Distinguishing Features

The clown loach has a distinctively ‘catfish-like’ appearance. With an arched profile and a flat bottom, this fish usually has a base color of one shade of orange or another similar color. Some clown loaches can be dull orange or pale yellowish, while others are so bright as to be almost sunshine yellow.

Regardless of their specific color, the pattern on clown loaches remains relatively consistent. The base color is interrupted by three vertical bands of darker shading. Each stripe looks a bit like a boat’s sail or triangle, with one point aimed at the bottom of the fish.

Starting at the mouth, the first stripe on a clown loach runs through the eye and extends just below it. The second stripe is ahead of the dorsal fin and extends through the body to the pectoral fin. The last stripe emerges from the bottom of the dorsal fin and sweeps across the body to the anal fin.

Most clown loaches have reddish fins. This trait may be responsible for their moniker, as some say their red fins resemble a clown’s shoes. But, some clown loaches, especially those from the waters around Borneo, have a darker or even black fin coloration on their pectoral fins.

Aside from their red fins, these fish are also known for their playfulness and high energy levels, contributing to their ‘clownish’ reputation. The clown loach also has short whiskers on its lower lip and a split tail fin.

If you look at a clown loach very closely, you may notice a clump of sharp spines near the eyes. These spires are a defense mechanism, and while the clown loach isn’t poisonous, the spines are quite sharp and can easily injure a predator or unwary fishkeeper.

You should be mindful of these spires, and their tendency to come up in times of distress, any time you’re working around or netting your clown loaches. Be gentle to avoid damaging them if your fish becomes caught in your net.

If you ever walk past your tank and hear a strange clicking sound, it might be coming from your clown loaches. These fish can produce sounds by grinding their teeth. While their ‘language’ isn’t understood, it’s clear that clown loaches make their clicking noises when they are mating, asserting their territory, or content in their environment.

Clown Loach Sitting on Bottom of Tank


The clown loach’s native territory includes the inland waterways of Indonesia, particularly the islands of Sumatra and Borneo. They are also found in Malaysia. In their local habitat, they spawn in large numbers and serve as a food source for other larger fish in the area, especially when they’re still relatively small juveniles.

Their native waters are tropical and warm rivers with slow-moving, eddying currents. Since their habitat is also prone to floods, especially during monsoon season, these fish are also quite comfortable in relatively shallow ponds. They can handle changing water conditions, as they’re pretty hardy.

But, for best results in a home aquarium, you should aim for consistently optimal water conditions. In nature, their home usually has a sandy substrate, perhaps marked by relatively fine gravel and larger stones. The water should be relatively clear, though these fish will tolerate a bit of stirred-up sediment.

Their natural waters are heavily vegetated, with floating plants overhead and ample shadows below. They will tolerate brackish water, but saltwater is lethal, and clown loaches prefer and thrive in freshwater.


If you’re thinking about adding one or more clown loaches to your tank, it’s crucial to understand their potential size. While these fish are young, they can be fairly small.

A wild clown loach can become enormous over time with good conditions and plenty of food. You should expect a clown loach to grow about two inches per year in a home aquarium. Slow, steady growth will continue, and even in a relatively small aquarium, they may attain a size of twelve or more inches in length.

Even with large tanks and ideal conditions, clown loaches can outgrow their surroundings when they grow to maturity. So, you need to plan for the future when considering tank size for your fish.

In general, expect a well-fed clown loach to reach anywhere from six to nine inches in length in a home aquarium. But, be wary of continued growth that can leave you with a massive fish in too small of a tank. A typical aquarium-kept loach might be about the size of a football.

Male and female clown loaches are typically the same size.


A well-cared-for clown loach, given plenty of room in a large tank, can live for a decade or more. Sub-optimal conditions can negatively impact their lifespan, though these fish are pretty tough.

Some fish keepers report that clown loaches can live longer than ten years. There are rumors that some clown loaches at the Basel Zoo are almost twenty years old.


Clown loaches are about the same size, regardless of gender. But, females appear much plumper than their male counterparts. Males also tend to have a larger tail, with a more distinct v-shape. Males may also have a bit more brightness to their coloring.

Clown Loach on Rock


Clown loaches are known for being easy-going, affable, and peaceful. They are pretty active swimmers, and their playfulness is extraordinary.

Some keepers relate that they have even seen fish pick up pebbles in their mouth and play ‘keep-away’ games with their clown loach tank mates. They enjoy socializing in groups, and solitude can unnerve them. For the best results, it’s advisable to keep the largest number of clown loaches you can while recognizing that they can get pretty big.

Males and females are similarly calm, and since they rarely breed in captivity, little is known about their mating habits or any upticks in aggression during them.

Tank Parameters

Clown loach owners must prepare for them to grow quite large. This is probably the single biggest issue posed by keeping clown loaches in an aquarium.

Minimum Tank Size

Clown loaches like to swim in schools. If you have a single clown loach, they will likely be shy, dull, and sad. With six or more together, you’ll see an uptick in captivity but probably still quite shy.

With a dozen or more clown loaches, you’re most likely to see high activity levels and displays of their famous, clownish behavior. But, since these fish are easily more than eight inches when fully grown, and some can get much larger, you need a large tank.

While a 55-gallon tank might suffice, a 100-gallon tank would be better. While these are pretty large tanks, they might start to look small as your clown loaches grow two inches or more every year. And, since they can live for decades in captivity, you need to look to the future.

Here are a couple of quick references regarding tank size:

  • A school of juvenile clown loaches requires a tank of 55 gallons at the absolute minimum
  • A single fully-grown adult requires a 30-gallon tank
  • Five adult clown loaches need a 150-gallon tank

Water Parameters

For the best results, you need to mimic the tropical waters that are the clown loach’s native habitat. Your home aquarium needs to offer ample swimming space, lots of shade, and places to hide.

Clown Loach on White Gravel


The ideal temperature for clown loach tanks is right around 78 or 79 degrees (Fahrenheit). While they will tolerate temperatures up to 85 or as low as 75 degrees, look for the sweet spot roughly in the middle.

Some keepers prefer to keep their clown loaches in warmer water, mostly as a defense against disease and parasites. Anecdotally, clown loaches are more active and tend to live longer in warmer waters.

Clown loaches do not like drastic changes in the water temperature, especially sudden cool-offs. So, it’s a good idea to have a backup heating element in case of primary heater failure. You may even want to consider a battery backup or generator system in case of a commercial power failure or blackout.


Clown loaches prefer neutral to slightly acidic water. A clown loach can probably survive in a tank with a pH between six and eight. But, as a rule, you should aim for something right around 7.4 to 7.6, while tolerating an up- or downtick.

It’s best to maintain your tank’s pH consistently.


Clown loaches are freshwater fish. So, they don’t want anything as salty as seawater in their tank. But, they tolerate fairly hard water quite well, so you may be able to fill your tank from the tap.

Tank Setup

Again, mimicking nature is your first rule when designing an aquarium for any fish. Keep this in mind for your clown loach aquarium.

Also, remember that clown loaches are bottom dwellers. They will mostly congregate at the water’s lowest levels, leaving lots of room at the tank’s top for vegetation and mates.


Your substrate should be mostly sandy, with small pebbles and gravel mixed in.


Loaches thrive in tanks with ample hiding places. Use caves, rocks, driftwood, and vegetation to keep them happy. You can also use PVC pipes to create buried, hidden passages for your fish.

Clown Loach in Aquarium Swimming on Gravel


Consider using a large amount of vegetation in a clown loach tank. Plants that mimic their natural environment work best, including

  • Java Moss
  • Hornwort
  • Riccia fluitans
  • Amazon Sword


In general, a clown loach tank should have plenty of shadows and subdued relatively calm lighting. Make sure to use a timer to establish the day-to-night cycle, and reduce the amount of light if your fish seem overly skittish or shy.


Your filter needs to be quite powerful to maintain a tank that is nitrate and ammonia free, while also providing a mild current.


Heating is essential for a clown loach tank. Some keepers prefer to keep their clown loach tanks near the upper range of temperatures, approaching 85 degrees. Others stick closer to 78 or 79 degrees. Either way, you’ll need a heater powerful enough for your large clown loach tank.


Clown loaches are omnivorous. They will eat almost anything given to them. If they have a favorite food, it’s probably live worms. Clown loaches should receive a mixed diet of various nutritious foods, without overfeeding.

For example, you might offer a daily diet of algae wafers and shrimp pellets. They will also scavenge any leftover fish flakes that sink to the bottom of the tank before their tank mates can finish them.

Then, use calorie-rich foods like frozen bloodworms and shrimp a few times throughout the week, but not daily. Finally, offer live food like bloodworms, earthworms, and small shrimp maybe once per week as a treat. If you use earthworms from your home’s yard, make sure the soil isn’t treated with chemicals.

You can even feed freshwater snails to your clown loaches, as these snails and small crustaceans are part of their natural diet. You can even raise snails in a separate tank to use as a food source.

In general feed your fish two or three times per day, sticking to small amounts with no leftovers.


Though determining their gender is fairly easy, there are few reported cases of clown loaches breeding in captivity. Therefore, most clown loaches you find for sale are wild-caught.

However, you can optimize breeding conditions by first finding a pair of sexually mature clown loaches. Then, follow a few steps.

  • Separate the male and female into separate, nearly identical tanks with lots of nutritious food.
  • Remain alert for growing plumpness in the female, an indication she is holding eggs. It may take a few weeks.
  • When the female is distinctively larger, put both fish in a tank with lots of vegetation, subdued lighting, and high water quality.
  • Maintain a temperature between 77.9 and 79.7 degrees Fahrenheit, with a pH of 6.2 to 6.4 at all times.
  • Look for the female to release her eggs and the male to swim along and fertilize them. The eggs should look wiggly and pink (eggs that aren’t fertilized will be dull brown in time).
  • Remove both fish from this tank and return them to their normal environment.

If you see the eggs begin to hatch, feed the hatchlings (fry) a diet of infusoria. As they grow, start adding in whole food sources like ground-up fish flakes and the smallest brine shrimp you can find.

Breeding clown loaches in captivity is notoriously difficult.


Common Diseases

The biggest disease threat to a clown loach is the Ich parasite. Any time you add a clown loach to a fish tank, consider doing so only after a quarantine period. Keeping them separate for a time will help reduce the risk of them introducing this and other parasites to your tank.

Ich, or white spot disease, is particularly dangerous to clown loaches and they may be the first to show signs of infection like lethargy or rubbing on objects. The good news is that frequent water changes and routine testing can greatly reduce the risk of Ich.

If you do have an Ich outbreak, purchase an over-the-counter treatment and follow the instructions on the label for how to use it. You’ll likely have to quarantine the affected fish and increase the water temperature.

Potential Tank Mates

The best tank mates for clown loaches are similarly peaceful. Never introduce a predatory fish into a tank with clown loaches.

When considering friends to let swim with your clown loaches, think of those that swim in their same native waters like the barred rainbowfish, comb-spined catfish, and tiger barbs.

For your aquarium, look to fish of similar temperament and water preferences like tiger barbs, cherry barbs, tetras (especially neon and black widow), angelfish, discus, and even other species of loach.

Wrap Up

If you prepare for them to grow quite large, keeping a school of clown loaches in your aquarium is pretty simple. They demand a lot of space as they grow, and they’re quite hard to breed in captivity. But even for novice fishkeepers, the playful antics of the clown loach are quite appealing.

Just make sure you have a big tank and a long-term plan, as these fish can live for a long time. That means you need to be ready to care for them in the future. If you’re ready to commit to a long-term relationship, get some clown loaches today!