April 14

Dojo Loach – Care, Feeding and Breeding Guide


Dojo Loach

Dojo Loach is a freshwater fish with some unusual characteristics. It is native to Asian waters from Japan to Korea, China, and Vietnam. It has an elongated body and can grow to a length of 25cm.

Though the tank for keeping dojo loach may not be necessarily big; it has to have a good depth as this fish loves swimming at all levels, and may even attempt to jump out. Aquarists love them for their undemanding nature and calm temperament.

Dojo loach may appear to be more than just another fish when one considers its weather-reading ability. Besides, its endurance is second to none in the aquatic world as it can hibernate and survive without water for a long period.

Find out more on how you can breed the dojo loach, and about their interesting features and behavioral pattern in this explicitly written article. We also shed light on how you can select the appropriate tank-mates for them.


The Dojo Loach has many varied names – the Pond Loach, Weather loach, or weatherfish.  In addition, this is named depending on where it is found – the Japanese Loach or the Chinese Loach.  While there are apt reasons for the Loach being called so, the zoological nomenclature of this variety of fish is Misgurnusanguillicaudatus.  Now to look back at the reasons why this fish has varied names – this fish seems to have some intuition about the weather and tends to get very active and restless when there are upcoming weather changes.  This fish seems to be able to predict even earthquakes and tsunamis. This could have been a primary reason, why this has been in homes for a long time as the weather forecast is only a recent discovery!

This was predominantly an Asian fish, found mostly in Japan and China but now is found widely in most parts of the world including Russia and Siberia.  The Loach is consumed as food in some parts of the world, and in some is used as bait to catch bigger fish.  Interestingly the number of fish of this species is found to be increasing, and possible reasons could be their increased breeding or the escape routes they take when they are used as baits.  Dojo loaches have their homes in freshwaters – whether they are rivers or ponds or even in paddy fields.  They like mud-covered layers of soil at the bottom and hence can thrive even when there is not much water. 

They have additional pores on their skin to absorb oxygen and can also breathe through their intestine.  Even if there is no water, they can tap this oxygen for living in muddy or damp areas for a long period of time.  The loaches that are breeding naturally are also causing concern to society, as they are proving to be a threat to most of the smaller insects and fish that are found in and around their habitat.  Studies are going on to see how this can be minimized.

The loach looks more like it belongs to the eel family with a long body and is either golden brown or greenish-grey in color.  They have a tiny mouth, thick lips, and six barbells. This is a friendly fish and enjoys being touched and pampered, and can be trained to eat out of our hands making it an ideal pet.  The loaches are characterized by pectoral fins, and the male has more pronounced fins than their female counterparts. 

The size of Dojo Loaches in an aquarium can be 15 cm long, whereas the ones that grow in the natural surroundings can grow to almost double the size.

Their life span can be anywhere between 7 to 10 years. This fish prefers acidic backgrounds, and the ideal pH levels can vary from 6.5 to 8.  They also amongst the fishes that prefer cold temperatures and thrive well between 24 to 28 degrees Celsius. 

Warmer temperatures are not very conducive for the loaches, and this can impact their life span to about four years.  Since they also like to live in groups, it is always better to keep more than 2 of them together as they like to be cozy with their bodies touching when they rest.


The Dojo Loach is easy to feed, as these fish can eat anything from fish feed to snails.  They have the ability to eat up anything that comes in contact with them, and then they will just spit over the foods that are not required.  The loaches just adore green peas, but they need to be skinned before putting them into the aquarium.  They also like to eat cooked or blanched vegetables, so they can be fed some of these as an alternative.  While those growing out in the open feast on small insects and larva, the ones that are being nurtured in the aquariums can be fed fresh or frozen shrimps, fish pellets or tablets, or mosquito larva. 

Loaches can be used to treat snail infections in tanks, as they love to devour the snails.  However, there are views that the speed with which they eat up the snails is not great enough to take care of the infections and hence may not be a great remedy.  The other problem that needs to be noted is that they like to eat up fish eggs, so if there are fish that are breeding in the same tank, then it is better not to have the loaches around. 

Since they can be fed many times a day in small quantities, it is better to give them a variety of food in a day – some wafers of algae at one time, some sinking pellets, live earthworms for one serving, and maybe some peas for one.  They are sure to enjoy all of these different varieties of food.  They also eat the smaller fish that are in the tank, so it is close to impossible to put smaller fish in the tank with the loaches. 


There is some sort of difficulty in breeding the Dojo Loach.  The females are slightly bigger and more wholesome than their male counterparts, and there is very little knowledge of how exactly to breed them.  Of the few points that we know, one of them is to have a cooler temperature when it is time to breed, and also to reduce the light in the aquarium so that the loaches can breed naturally.  The ideal time of breeding starts from winter to spring – so the light needs to be adjusted accordingly. 

    The light can be brought to a bare minimum during winter and then as spring approaches; it can be increased gradually.  Ideally, when spring arrives, the loaches should be getting about half a day of light.  This will trigger breeding amongst them. While breeding happens between one of the males and the females in the tank, the other adult fish especially the males act in a very agitated mode.  Unlike their usual stance, they even step up to the topmost area of the tank and try to even reach out to the female who is mating.  However, all of these are very temporary behaviors and settles down soon.

    When the fishes are ready to breed, the male fish approaches the female fish and starts courting it.  This courtship can last for several hours, and in the process, the male would have engulfed its female completely.  This position is altered only when the complete breeding is over – that is when the female has laid the eggs, and the male has fertilized them.  This happens a few times with the female laying anywhere around fifty eggs each of the times and the male fertilizing it.  Overall the whole courtship process can take about 3 to 4 hrs.  Breeding in a tank is considerably difficult, but the temperature of the water can instigate it.  The fertilized eggs that are dispelled from the body of the female start to hatch in about 2- 3 days.

    The male and the female who had gone through the breeding process have nothing to do when the baby fish or fry start swimming around.  Pretty much like goldfish, neither of the parents care for their children, and the fries are almost left to fend for themselves.  The young ones are too tiny and have to be specially fed to become capable of swimming around.  After this, the young loaches can be served baby fish food, powdered shrimps, and algae.  In some time this fry turns into healthy young fish and starts breeding when they are about two years old.


    Dojo loaches need close to pure water for them to survive. This leaves us with a need to filter the water many times before using it for the tank where the loaches will be put.  These fishes are the perfect drama artists in every aspect.  So it is best to use high-quality filters as you do not want one of them slipping out in the process of the filtering only to be found on the floor sometime later.  So these fishes cannot be nurtured by beginners as it may be difficult for them to maintain them. 

    Dojo loaches need close to pure water for them to survive. This leaves us with a need to filter the water many times before using it for the tank where the loaches will be put.  These fishes are the perfect drama artists in every aspect.  So it is best to use high-quality filters as you do not want one of them slipping out in the process of the filtering only to be found on the floor sometime later.  So these fishes cannot be nurtured by beginners as it may be difficult for them to maintain them. 

    The loaches can also slip out of the aquariums through any openings in the tank and can be found completely dried out on the floor many hours later.  Loaches have the ability to stay alive for few hours without water and once they are found dried out, they can still be replaced into the tank, and more often than not, they are up and alive in no time.  So, the key is to spot the loaches that have run out of the tank and replace them immediately, so there is a good chance to revive them back to life.

    The other point to be noted is the temperature of the water.  The water in the tank where the loaches are housed should always be cool and never heated.  The only exception is when the temperature goes down to less than 10 degrees Celsius.  Since the lifespan of the loaches is directly impacted by the temperature of the water, this is an important factor to be noted.  While the loaches can live up to 10 years in cold water, their life span can be reduced to up to 4 years if the temperature of the water is increased.

    The water needs to be changed every week as loaches need fresh water with good oxygen levels to survive, so the tank has to be cleaned at least once in a week.  These fish also have the tendency to eat up everything and throw out everything they may not need, so it is important to clean the sand and the gravel in the tank as well to clear out all these unwanted food junks.  So a complete clean-up of the tank becomes mandatory almost every week.

    The loaches are very lethargic during the day but become active as the evening approaches.  Since they like to sleep all during the day, the tanks that house the loaches should have a lot of protection for them where they can hide while they sleep.  So planks, tubes, flowerpots are all welcome additions to the tank of the loaches.

    Loaches keep to themselves, and if there is just one of them in the tank, then that one is going to be more in hiding than out in the open.  So when loaches are housed, it is better to have them in groups as that would keep them happy.


    Special care has to be taken while putting in loaches with other fish in an aquarium as this does not react well to stress.  Changes in the temperature of the water can induce stress levels, and that creates a series of diseases in the fishes.  While Ich is common to most fishes bred in aquariums, loaches are more sensitive to this, and they are affected in no time. 

    The reason is that this type of fish has scanty scales that attributes to more skin exposure.  Loaches develop white spots on their skin, and this needs to be treated immediately.  Medications needed for loaches are almost only half that is needed for other species, so that has to be taken into consideration when treating them.

    The skinny disease is one of the other diseases that loaches can be afflicted with.  It is very easy to observe this because as the name suggests, the fish might be eating the same amounts of the well-balanced diet and yet losing weight.  The internal parasites that are in the body of the loaches are the main reason for the weight loss, and this can be treated with appropriate medications.

    In a way, it is good to have weather loaches in the aquarium as they will be the first ones to be affected by these diseases as they are extremely sensitive.  This will act as a warning to protect the other fish. Most of the time, the best way is to completely treat the tank in case these diseases are noticed in the fish tank. 

    As is common knowledge, prevention is always better than getting these diseases cured, and so utmost care has to be taken when adding anything to the tank.  If adding new fish, it best to be sure that the fish are healthy and are not carrying any germs or bacteria.  The same applies to any plants or food that is added to the tank.  This, by all means, is the best way to safeguard all the fish in the tank.


    Loaches are friendly fish to have in a tank of the same species. They believe in the concept of more the merrier. One of them in the tank can be very shy and undercover most of the time, while a few of them in the tank would be seen happily swimming around.  They love to be in bigger groups, and they can form groups of six. Their level of aggression comes down by a considerable margin when they are housed in groups in the same tank. They love to be with other loaches in the tank and generally prefer fish that like to stay in the middle of the upper portions of the tank. 

    Loaches are peaceful fish and are ideal to be bred in aquariums.  However they like to keep digging around in the gravel for any leftover food, and they can uproot any plants that are placed there.  So, when loaches are placed in the tank, care has to be taken that the plants are either firmly planted or placed in pots that cannot be dug out by these fishes.  Loaches react to stress by burying themselves in the gravel at the bottom of the tank, so they may continue to disappear only to reappear a little while later.

    Aquarium mates

    Loaches like to have fishes with similar qualities in the tank and can be placed with fishes that also prefer cooler temperatures.  White cloud mountain minnows are the most compatible fish to be placed in the tank with the loaches.  It is best to put the loaches in a tank altogether, and they will all be happy there.  

    Care should be taken not to put in smaller fish, as the loaches have a tendency to look at them as food and eat them up.  So it is not a good idea to put in shrimps, snails, or any small fish in a tank of loaches.

     In fact, if there are snail infections, then it is a good idea to put in loaches there to get the infection cleared off.  Umbrella cichlids, female swordtail fish, rubber lip pleco are some of the other fish that can be put in the tank along with the loaches. Goldfishes are ideal mates for the Dojo Loaches.  In general, they like to be with fish that can swim in the upper portions of the tank, the reason for this is then they will not have to share the tank space with those kinds of fish and the loaches can have their space.


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