Polka Dot Loach

Burmese Border Loach, Marble Loach, Cloud Botia

Family: Cobitidae Polka Dot Loach, Botia kubotai, Burmese Border Loach, Marble Loach, Cloud BotiaBotia kubotaiPhoto © Animal-World: Courtesy Ken Childs
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I have two large tanks and over the years I have bought nine botias that were sold as Botia Kubotai (polka dot botias). It turns out five are polka dots, three are... (more)  Shawn Walsh Arey

The Burmese Border Loach is a more recent "polka dot" beauty that's curious and friendly with its aquarium keeper!

The Polka Dot Loach Botia kubotai is a more recent arrival to the hobby. They were first collected in 2002 during an expedition to the Three Pagodas Pass area in Myanmar (Burma) in an effort to find new aquarium fish. Though commonly known as the Polka Dot Loach or Burmese Border Loach, this gorgeous fish has captured the imagination of aquarists everywhere. With its distinctive color and patterning it has earned a variety of descriptive names such as Marble Loach, Cloud Botia, Polka Dot Botia, Botia "Angelicus", and Angelicus Loach.

The Polka Dot Loach will obtain their most beautiful color and patterning as adults, which is dramatically different then when they are juveniles. Their patterning is made up of yellow spotted horizontal black stripes that are interspersed with yellow spotted vertical bars. They have dramatic color changes as they get older with no two fish having exactly the same pattern. The black bars and stripes widen and there is lots of variation in the size and number of spots.

These are medium sized loaches that have fast become popular aquarium fish. Once Burmese Border Loaches are secure in their environment they can become quite tame. They can easily learn to be hand-fed which is another wonderful trait that makes them an enjoyable addition to the aquarium. Although a good community fish with similar sized tank mates, they do have a bit of an attitude and may snack on fish under 3/4" long, as well as snails. They enjoy the company of their own species and are best kept in a group of about four, smaller groups will take longer to acclimate.

They are from the normally slow flowing sections of streams and tributary rivers. Good water movement along with hiding and resting places among rocks and driftwood will be appreciated. They are not as hardy as many fish and need good water conditions.

For Information on keeping freshwater fish, see:
Freshwater Aquarium Guide: Aquarium Setup and Care

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Cypriniformes
  • Family: Cobitidae
  • Genus: Botia
  • Species: kubotai
Polka-Dot Boxfish, Yellow Boxfish, Ostracion cubicus
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Yellow polka-dotted juvenile in the wild.

The Polka-Dot Boxfish, also called the Yellow Boxfish or Cube Boxfish is another fish that thinks it's a dog! They need to be fed at least 3 times a day or more, and never fed floating food since they will develop buoyancy problems if they ingest air. They are very peaceful and need lots of places to hide when first added to the tank. They will not eat for up to a week and if startled or stressed will jump out of the tank or release a toxin that, while in the wild is quickly diluted by the ocean, yet in captivity can wipe out an entire tank. If they are near death or tank mates are irritating it, remove promptly as this toxin has no remedy. They reach over 17" and need a tank that is at least 125 gallons and need an advanced aquarist who understands their delicate nature.

Polka-Dot Boxfish, Yellow Boxfish, Ostracion cubicus
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Polka-Dot Boxfish in the wild.

The adult coloring of the Polka-Dot Boxfish is what has earned it the name Yellow boxfish, since the intense black dots fade as they age. Growing to almost 1.5 feet long, they need a tank that is at least 125 gallons with plenty of open space along with caves and areas to hide. They like a meaty diet and are very peaceful, although should only be kept by advanced aquarists due to their specific needs. If a tank mate picks on them or a fast swimming tank mate startles them badly, they can emit a toxin that will kill the entire tank, including themselves. Put a lid on it..... quite literally, because they can jump from the tank! However, them jumping out of the tank may be a better alternative than releasing toxin. Both situations are not desirable, so leaving them in the ocean may be the best choice.

Polka Dot Loach - Quick Aquarium Care
  • Aquarist Experience Level: Intermediate
  • Size of fish - inches: 4.7 inches (11.99 cm)
  • Minimum Tank Size: 30 gal (114 L)
  • Temperament: Peaceful
  • Aquarium Hardiness: Moderately hardy
  • Temperature: 75.0 to 82.0° F (23.9 to 27.8° C)
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Habitat: Distribution / Background

The Polka Dot Loach Botia kubotai was described by Kottelat in 2004. It is found in Asia in the Three Pagodas Pass area in Myanmar (Burma). These loaches are endemic to the Salween River basin around the boarder between Thailand and Myanmar. They have also been discovered in Hanthayaw River in Thailand. This species is listed on the IUCN Red List as Data Deficient (DD) as little is know about its population trends. Other common names it is know by are Burmese Border Loach, Marble Loach, Cloud Botia, Polka Dot Botia, Botia "Angelicus", and Angelicus Loach.

They are found in streams and tributary rivers in their natural habitat. Their habitat is normally slow flowing sections under forest shaded canopies. The waters are normally well oxygenated with a mix of sand and rocks for the substrate, littered with leaf debris and submerged driftwood. Some of the regions have dense aquatic vegetation. Presumably they are a benthic predator feeding on insects, crustaceans, and other small aquatic organisms.

  • Scientific Name: Botia kubotai
  • Social Grouping: Groups
  • IUCN Red List: DD - Data Deficient


The Polka Dot Loach is a medium sized loach that can get up to about 4 or 5" (10-12 cm) in the aquarium, though they are reportedly smaller in the wild, reaching only 3.35 inches (8.5 cm) in length. Their likely life span is about 8 - 12 years.

They will obtain their most beautiful color and patterning as adults, which is dramatically different then when they are juveniles. Their patterning is made up of yellow spotted horizontal black stripes that are interspersed with yellow spotted vertical bars. They have dramatic color changes as they get older with no two fish having exactly the same pattern. The black bars and stripes widen and there is lots of variation in the size and number of spots.

  • Size of fish - inches: 4.7 inches (11.99 cm) - This fish only reaches about only 3.35 inches (8.5 cm) in the wild, but can reach up to about 4 or 5 inches (10 - 12 cm) in the aquarium.
  • Lifespan: 12 years - This fish has a lifespan of about 8 - 12 years.

Fish Keeping Difficulty

This loach can be hardy under the right conditions. However they are not recommended for beginners because of their need for pristine water and they do not have scales. Do not try to introduce these fish into biologically immature tanks. Not having scales make them more prone to disease and very sensitive to medications used to treat disease. Experience in treating scaleless fish is very important to be able to give your loach a healthy and long life.

  • Aquarium Hardiness: Moderately hardy
  • Aquarist Experience Level: Intermediate

Foods and Feeding

Since they are omnivorous, the Polka Dot Loach will generally eat all kinds of live foods, sinking pelleted and tablet foods, flakes, and algae. They like frozen foods as well. To keep a good balance give them a high quality flake or tablet food everyday. Feed brine shrimp (either live or frozen) as a treat. They also like mosquito larvae, tubifex, daphnia, and vegetable foods such as algae wafers. They will also eat snails, so are good for snail control.

  • Diet Type: Omnivore
  • Flake Food: Yes
  • Tablet / Pellet: Yes
  • Live foods (fishes, shrimps, worms): Some of Diet
  • Vegetable Food: Some of Diet
  • Meaty Food: Most of Diet
  • Feeding Frequency: Several feedings per day

Aquarium Care

The most important thing for these loaches is that they always have clean and well-oxygenated water. Frequent water changes of about 30% a week are needed for the Bengal Loach. With your weekly water change make sure to vacuum the gravel to remove all excess food and waste. Make sure not to remove the bio film on rocks, decor or no viewing panes of the tank. A magnet algae cleaner normally does a great job in keeping the viewing pane clear.

  • Water Changes: Weekly - Water changes of about 30% weekly.

Aquarium Setup

The Polka Dot Loach will swim mostly on the bottom of the aquarium, but will also swim in the middle of the aquarium. Never introduce this loach into a biological immature setup as these fish require pristine water. Because these fish do best in groups, a larger tank of at least 30 gallons will work best. They do best in soft, slightly acidic water with subdued lighting. They also need good water movement that provides plenty of oxygenation. The tank water should turnover at least 10-15 times per hour. An undergravel filter is a great choice for these fish as it creates high oxygen through out the tank as well as reducing the waste. Adding a canister filter or power head to the setup will make the proper current for this loach.

It is recommended to have a tank set-up that resembles its natural habitat, slow to moderate moving rivers. Because they are burrowers, the substrate needs to be a fine smooth gravel or sand that does not have sharp edges. The tank needs to have ample hiding places for this shy fish. Larger smooth rocks can be used as hiding places. Driftwood and branches can also be added to provide shade and places for quick retreat. Be sure to provide hardy plants with the roots protected and have decorations firmly placed on the glass bottom so they don't fall over. Plastic tubes also make safe and excellent hiding places.

  • Minimum Tank Size: 30 gal (114 L)
  • Suitable for Nano Tank: No
  • Substrate Type: Sand
  • Lighting Needs: Low - subdued lighting
  • Temperature: 75.0 to 82.0° F (23.9 to 27.8° C)
  • Range ph: 6.8-7.3
  • Hardness Range: 2 - 9 dGH
  • Brackish: No
  • Water Movement: Moderate
  • Water Region: Bottom - These fish are mostly bottom dwellers, but will also swim in the middle of the aquarium.

Social Behaviors

A good community fish, they will tolerate other tank mates of a similar size as well as enjoy other members of their own species. It is recommended that they be kept in groups of at least 4, with larger groups acclimating easier than smaller groups. They may snack on fish under 3/4" as well as snails. Be cautious adding slow swimming long finned tank mates, these loach will nip fins. Good for snail control! Lively and fun to watch.

  • Venomous: No
  • Temperament: Peaceful
  • Compatible with:
    • Same species - conspecifics: Yes - Best kept in groups of 4 or more.
    • Peaceful fish (): Safe
    • Semi-Aggressive (): Monitor
    • Aggressive (): Threat
    • Large Semi-Aggressive (): Threat
    • Large Aggressive, Predatory (): Threat
    • Slow Swimmers & Eaters (): Monitor - This loach will nip long-finned, slow swimmers.
    • Shrimps, Crabs, Snails: May be aggressive - Will eat snails.
    • Plants: Safe

Sex: Sexual differences

Sexually mature females are normally fuller-bodied than males with a rounded snout whereas males have an elongated snout with noticeably fleshier lips.

Breeding / Reproduction

There are no reports of the Polka Dot Loach having been bred by hobbyists. They are not yet bred commercially.

  • Ease of Breeding: Unknown

Fish Diseases

Loaches are more susceptible to disease than other aquarium fishes. This may have to do with the faint body scales and no head scales. So take caution when introducing these fish to an established tank. They are also very sensitive to different medications used to treat many diseases; a separate hospital tank is needed. Cold water and condition changes can also cause stress to this fish which makes them even more prone to disease.

Most common disease that affects this loach is Ich. Ich is short for Ichthyophthirius, also known as "white spot disease". It is a parasite that can attack nearly all aquarium fishes, but you'll find that loaches are often the first to be attacked. Take great care in treating ick as loaches are very sensitive to the medications used to treat it. Often the dose is half of what is normally used.

The second most common thing that affects loaches is a thing called skinny disease. This can be diagnosed fairly easily. If your loaches are eating a nitrous and healthy amounts and still seems to loose weight it is a good chance it has skinny disease. This is caused by internal parasites and can be treated with medication if used carefully.

An outbreak of disease can often be limited to just one or a few fishes if you deal with it at an early stage. When keeping these sensitive types of fish, it is common to catch deteriorating water conditions and disease before other fish are affected. The best way to proactively prevent disease is to give your Polka Dot Loach the proper environment and give them a well balanced diet. The closer to their natural habitat the less stress the fish will have, making them healthier and happy. A stressed fish will is more likely to acquire disease.

Anything you add to your tank can bring disease to your tank. Not only other fish but plants, substrate, and decorations can harbor bacteria. Take great care and make sure to properly clean or quarantine anything that you add to an established tank so not to upset the balance. It is recommended to read up on the common tank diseases. Knowing the signs and catching and treating them early makes a huge difference. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.


The Polka Dot Loach, also called a Burmese Border Loach, Marble Loach, or Botia "Angelicus, is becoming popular and more readily available.


Author: Clarice Brough CFS, Jeremy Roche
Lastest Animal Stories on Polka Dot Loach

Shawn Walsh Arey - 2014-07-26
I have two large tanks and over the years I have bought nine botias that were sold as Botia Kubotai (polka dot botias). It turns out five are polka dots, three are histrionicas, and one is a botia I have never seen before. It is in-between the size of an polka dot and a yo-yo. Approximately, 4 ½ inches. It’s coloring is almost black with a pattern in a dark grey with one small yellow area. It snout is shorter like the polka dot, not as long as the yo-yos. Anybody have any ideas? I’ve searched everywhere and I can’t find one that looks like it.

  • Clarice Brough - 2014-08-05
    Can you upload some pictures of it?
Theresa Corbett - 2014-11-04
We have a pair of Polka Dot Loaches that we have had for a while now. We are quite new to keeping an aquarium and apart from a near mishap with medication our loaches have coped with whatever we have thrown at them and are currently the only residents in our tank. They are lovely looking fish and can be very playful.

Ike - 2012-12-29
Hey, anyone have advice on keeping marble loaches? I need feeding, habitat, and tankmate information.-----------Help!

  • Joel - 2013-03-26
    Hello Ike, though this is an older question, thought I'd throw my 2cents in. We feed our BBL's Hikari sinking wafers, Cobalt shrimp pellets, and Omega One veggie rounds as their main diet. We also make sure they get snails often, and seedless cucumber as a treat. We also feed them frozen bloodworms and mysis and brine shrimp as treats. You really should consider getting a larger tank before they get bigger, maybe a 40g long ? you'll want to provide hiding places galore for any of the Botia loaches, and it's good to have some 'dither fish' as tankmates. The dithers give your loaches the 'all clear' to come out of hiding. If you only have 3 loaches, the alfa loach may pick on the others and they will be stressed constantly. I really would suggest 5 as a minimum. As far as tank mates, we've done well with peaceful tetras. We have 6 full grown diamond tetras in our loach tank, with 7 BBL's, and 7 Clowns. Just make sure your tank revolves around your loaches needs first. We are currently running 1 big canister filter, 2 'hanger' filters, and a 750gph powerhead. You really need to be turning your tank water over 10-15 times an hour for loaches as they do need pristine water. We've been doing 30-50% water changes every 1-2 weeks. Loaches can survive with less maintenance, but they won't be happy, and probably won't live a full life. They are also much more entertaining. Hope this helps.
dennis donato - 2009-07-22
Hi, I just bought my first 10 gallon aquarium tank and I have 1 kissing gourami, 1 blue gourami (who by the way is very terratorial), 1 tri-color shark, and 1 algea eater. What other fresh water fish could I get for my tank. P.S. My fishs are about 2 1/2 to 3 inch. long.

  • Lori Henson - 2012-04-21
    Hi Dennis. I have always heard to stock your aquarium 1 inch of fish to 1 gallon. When counting fish inches you should consider their adult length. You are probably at your max.
  • Ike - 2012-12-29
    I agree. In my aquarium, which is ten gallons and was setup not long ago, I have only one Marble Loach (plan on getting two more) that is about one inch long and a two inch long Neon Blue Dwarf Gourami.