The Dojo loach is also known as the Pond loach. These attractive bottom-dwelling fish are moderately easy to care for and make an interesting addition to any peaceful community tank.
You can find the Dojo Loach in its natural, wild form, and there’s also a golden variant if you want to add a pop of color to your aquarium. These quirky fish make wonderful pets that can be trained to take food from your hand and they can even forecast the weather, hence their other common name, the Weather loach.
Read this guide to learn how to care for the fascinating Dojo Loach.
Dojo Loach – Overview
Scientific Name
Misgurnus anguillicaudatus
Common Name (species)
Dojo loach, Pond loach, Weather loach, Oriental Weatherfish, Chinese Weatherfish, Japanese Weatherfish, Golden Dojo loach, Albino Dojo loach
Family
Origin
Found in eastern Asia from Siberia and Sakhalin, in northeastern Asia, Myanmar, Central China, Japan, Hainan, and Korea
Diet
Omnivore
Care Level
Intermediate
Activity
Playful, burrower
Lifespan
7 to 10 years
Temperament
Peaceful
Tank Level
Primarily bottom-dweller but does visit the midwater and top area of the tank
Minimum Tank Size
55 gallons
Temperature Range
Tropical 50° to 77° Fahrenheit
Water Hardness
5 – 12 dGH
pH Range
6.5 to 7.5
Filtration/Flow Rate
Prefers a moderate flow with good filtration
Water type
Freshwater
Breeding
Egg layer but not bred commercially
Compatibility
Peaceful. Not suitable for a community with snails, shrimp, and very small fish
OK, for Planted Tanks?
Safe with plants but does like to burrow
Origins
The Dojo loach was first described in 1842 by Cantor.
Thanks to their wide range, these fish are listed on the IUCN Red List as being of least concern. However, in some areas, ecosystem degradation and increased agriculture are causing a decrease in numbers. Conversely, the overall global population of Dojo loaches is increasing, largely due to the introduction of the species into other countries, including Hawaii and Australia.
Weather loaches are found distributed right across eastern and northeastern Asia, Central China, Japan, Korea, and Hainan. As well as the wild variety, there’s a gold color morph called the Golden Dojo Loach.
As well as being collected for the aquarium trade, the fish are used by anglers as live fishing bait and as a food fish in Japan and other Asian countries.
Natural Habitat
Dojo loaches live in rivers, lakes, swamps, rice paddies, ponds, and other bodies of slow-moving water. The fish prefer locations where the bottom is muddy and easy for them to burrow into.
These fish are perfectly adapted to life in habitats where the water levels are variable, having the ability to gulp air from the water surface when oxygen levels are depleted. The loaches can also jump, surviving out of the water for relatively long periods provided that they are in moist mud or sandy conditions.
Dojo loaches feed on small crustaceans, worms, small aquatic creatures, insect larvae, and insects.
Appearance
The Dojo loach is eel-like in appearance with a long, cylindrical body that flattens toward the rear end. The fish has two pairs of barbels on its lower jaw and three around the upper part of its mouth.
Dojo loaches are usually brown to yellow in color with a marbled pattern of greenish-gray to dark brown on the upper part of the body, fading to a paler shade underneath.
You can also find a yellow-to-orange color morph of the fish that’s commonly called a Golden Dojo loach. These fish have thinner bodies than the regular variety, and their patterning is extremely faint.
Size
A full-grown Dojo loach in the aquarium measures around 6 inches in length, although they do grow to a much larger size in nature.
Life Expectancy
Dojo loaches live for between 7 to 10 years in captivity.
Activity Level/Temperament
The Dojo loach is a peaceful character, although these are pretty lively, active fish, especially at night. The fish spend much of their time scavenging on the bottom of the tank for scraps of food or burrowing and digging in the substrate.
One interesting quirk of the Dojo loach is its habit of becoming hyperactive when the weather conditions change, which is thought to be related to fluctuations in barometric pressure. These are very friendly fish that can be trained to take food from your hand, and they even seem to enjoy being touched and petted!
Compatibility and Tankmates
Tank Mates
Dojo loaches make a good addition to a community tank, provided that their companions are non-aggressive and not small enough to be regarded as a food source. As the loaches spend most of their time on the bottom of the tank, fish species that prefer to hang out in the upper regions of the tank are the best choice as tank mates.
Although they’re not strictly a shoaling species, Weather loaches are happiest when kept in groups of three fish or more.
Feeding
To keep your fish healthy and thriving, always use high-quality fish food. Cheap foods are usually stuffed with padding that has no nutritional value and can even make your fish sick.
What to Feed Your Dojo loaches
Dojo loaches are omnivores, which means they eat both meaty protein and vegetable matter.
In the wild, Dojo loaches eat insects, insect larvae, algae, small crustaceans, worms, and other tiny aquatic animals.
Captive Weather loaches are not picky feeders, and they will happily accept all types of live foods, tropical flakes, sinking pellets, and frozen foods. Give your fish a balanced diet of flakes or tablets every day, as well as algae wafers, and live or frozen blood worms, daphnia, or tubifex.
These fish also eat small snails, which can help to control the mollusk population in your fish tank.
How Much and How Often to Feed
Feed your loaches twice daily, only offering what they will clear up in a couple of minutes. Don’t overfeed your fish, as uneaten food will decompose in the tank and pollute the water.
Tank Requirements
Tank size
Dojo loaches need a tank of at least 55 gallons. The tank should be long rather than tall and extend to a length of at least 4 feet.
These feisty fish can and will jump right out of the tank, so make sure that your aquarium has a tightly fitting lid.
Tank Setup
Substrate
Weather loaches are great diggers, spending much of their time rooting through the substrate for scraps of food. They also like to bury themselves in the soft muddy substrate of their natural habitat, so you’ll need to use soft sand or very fine-gauge gravel that doesn’t have sharp pieces.
Decoration
Dojo loaches look best when displayed in a setting that replicates their natural habitat. So, choose plenty of smooth stones, driftwood, caves, and twisted roots that provide shelter and somewhere that these inquisitive fish can explore.
Plants are a good addition to the tank, but choose hardy species and ensure that the roots are very well anchored so that the fish don’t uproot them as they dig and burrow in the substrate.
Habitat Requirements
These loaches are not suited to a brand-new setup, as they need the absolutely pristine water conditions that are only provided by a mature tank.
Filtration
Good water movement is essential, as well as excellent oxygenation. With that in mind, we recommend an undergravel filter for loaches, as well as an external canister filter or powerheads.
Water Parameters
Water Temperature
Dojo loaches are tropical fish that can tolerate a broad range of water temperatures of between 50° and 77° F.
Water Hardness and pH Range
The aquarium water should have a pH in the range of 6.5 to 7.5, with a water hardness of 5 to 12 dKH. Loaches cannot tolerate brackish water.
Lighting
Dojo loaches prefer subdued lighting conditions, so pick an LED lighting unit that allows you to adjust the lighting levels in your tank accordingly, and be sure to pick plants that can thrive in low light conditions.
Tank Maintenance
Dojo loaches require pristine, well-oxygenated water to thrive. As well as an efficient filtration system, you’ll need to carry out weekly partial water changes of at least 30%. Vacuum the substrate, underneath rocks and wood, and around the base of plants to remove uneaten food, fish waste, and dead leaves.
You can use a magnet algae cleaner to keep the glass clear but be careful not to remove the bacteria and biofilm from the viewing panes or tank décor.
Rinse the filter media in dirty tank water once a month and change the media when required, as directed by the manufacturer.
Setting Up the Aquarium
Assemble everything you need to set up your tank, including:
- Sand or fine gravel substrate
- LED lighting unit
- Canister filtration system or powerhead
- Water conditioner
- Undergravel filter
- Heater
- Aquarium thermometer
- Twisted roots, smooth rocks, caves, driftwood
- Plants
How to Set up Your Aquarium
- Rinse the sand or gravel under running water to remove dust
- Put two to three inches of the substrate into your aquarium, and place an upturned bowl on the top of the gravel or sand.
- Fit the filter and heater in the tank, but don’t switch them on.
- Next, fill the aquarium with dechlorinated tap water. Pour the water over the bowl so that you don’t displace the substrate.
- The water must contain some ammonia to kick start the nitrogen cycle in the biological filter. To do that, you need to “seed” the water. You can do that by adding some substrate from an established setup, a little flake food, or a couple of drops of pure ammonia.
- Rinse the tank décor to get rid of dust, and arrange everything in the aquarium.
- Prepare your plants by trimming off any damaged or dead leaves or stems. When planting the plants, leave enough space between the stems so that they have room to spread.
- Switch on the heater and filter. If you have live plants in the tank, you’ll need to have the lights on for up to 10 hours a day.
- Allow at least ten days before introducing fish to the tank to give it time to cycle fully. To know when it’s safe to add fish, test the levels of ammonia, nitrites, and nitrates. Ammonia and nitrites must be zero, and nitrate levels should ideally be below 20ppm. If the levels are too high, you need to allow more time.
Health and Disease
Dojo loaches are pretty hardy fish. However, they are highly susceptible to poor water conditions, and they have faint body scales, which can leave them vulnerable to attack by parasites.
Also, loaches are very sensitive to some medications, so you should always treat them in a separate hospital tank.
Signs of Good Health
These fish are very active, curious creatures that should spend much of their time exploring their environment, digging, and burrowing in the substrate.
Although loaches tend to hang out on the bottom of the tank, you will also see them venturing to all areas.
Red Flags
There are some red flags that could indicate potential health problems, including:
- Not eating
- Inactivity
- Not socializing with tank mates
- Damage to the skin, such as ulcers, sores, or red patches
- Flicking against the substrate or solid objects in the tank
Common Health Issues and Treatment
Health Issue
Ich (White Spot Disease)
Symptoms or Causes
White Spot disease is caused by a free-swimming aquatic parasite called Ichthyophthirius multifiliis.Fish with Ich flick or rub their bodies against objects in the tank. As the disease progresses, a sprinkling of white dots develops over the fish’s gills, fins, and body.
Suggested Action
Raise the tank temperature to 82o F for three days, and treat the water with Ich medication.
Health Issue
Flukes
Symptoms or Causes
Flukes are aquatic parasites that append themselves to the gills or body of affected fish. Fish with flukes rub against solid objects and secrete excessive mucus.
Suggested Action
Treat the tank with an antiparasitic medication.
Health Issue
Fungal infections
Symptoms or Causes
White cotton-like growths.
Suggested Action
Quarantine affected fish, and treat with antifungal medication.
Health Issue
Bacterial infections
Symptoms or Causes
Caused by internal parasites. Fish lose weight despite eating well.
Suggested Action
Treat with antiparasitic medication.
Breeding
Dojo loaches are egg-layers, but they cannot be bred in the home tank and are typically farm-raised commercially or wild-caught.
Availability
Both the regular and golden variety of the Weather loach can be found in most good fish stores or purchased online, with prices beginning at around $6 or $7 per fish.
Product Recommendations
- Water conditioner/dechlorinator
- Algae magnet
- Aquarium thermometer
- Aquarium vacuum
- Books on keeping tropical fish
- Filtration system
- Aquarium (minimum size 55 gallons)
- Heater
- High-quality tropical fish flakes, pellets, algae wafers, frozen foods
- LED lighting unit
- Plants
- Smooth stones, driftwood, twisted roots, caves
- Sand or fine-gauge gravel substrate
Conclusion
I hope you enjoyed our comprehensive guide to caring for the fascinating Weather loach.
If you have these quirky, talented fish in your setup, we’d love to hear about them! Tell us about your Dojo loaches in the comments box below!
Remember to share our guide if you enjoyed it!
You might also be interested in our article about Reticulated Hillstream Loach – Care Guide!
Thanks for the article it was really helpful. I just wanted to know if I could keep 3 dojo loaches in a 75 gallon tank with my 3 year old common goldfish(stunted). Since there is lots of hornwort to absorb nitrates and the goldfish is only 6-7 inches I thought the water volume would be enough to dilute the massive bioload. I have heard stories of dojo loaches attacking goldfish and just wanted to know if the tank would be too cramped for these two species. Would a schedule of 40%-50% water changes every week be okay without ever having to upgrading to a new tank?
Hi Josh
Thanks for your comment. I’m so glad you found the article helpful.
Although goldfish and Dojo loaches can live together peacefully, you must provide a larger tank. It’s not so much for the bioload, as an efficient filtration system and regular water changes will handle that, the problem is more the loaches may become belligerent toward your goldfish if they’re too cramped.
As regards 40% to 50% water changes, I prefer not to change that much water. Although changing large amounts of water will dilute the nitrate levels in the water, you’re also in danger of removing a bunch of the beneficial bacteria that you need for efficient biofiltration. So, I think you would be best upscaling your tank as the loaches grow bigger.
Hope that helps!
Alison P.
Fellow fishkeeping enthusiast and site author