Weather loach female (left) and male (right)
Name: Misgurnus anguillicaudatus
Origin: Northeast Asia, China
Weather Loach 101
Common Name: Weather Loach, Weatherfish, Dojo Loach, Pond Loach, Golden Dojo
Origin: Asia - China, Korea, Japan - Often found in streams, ponds and rice paddies.
Category: Bottom Feeders & Catfish
Diet:Omnivore; Sinking algae wafers, tubifex worms, flake food, vegetables, snails, other fish's eggs.
Temperament: Peaceful fish that will not bother other fish, they will however eat the eggs of other fish. Friendly and can be seen at all times of the day, though it tends to be more nocturnal. The name "weather loach" is due to the erratic swimming patterns of the fish during drops in barometric pressure. These swimming patterns are like an underwater ballet, usually resulting in the fish diving down rapidly, and burying themselves in the substrate.
Care: It is recommended that you provide caves and other dark hiding places. The fish likes to burrow, so provide a fine, soft substrate. A fairly large tank is recommended, as the fish can reach 25 cm or more, but sizes of 12.5 cm - 20 cm are more common. I have one who is on the larger end of the spectrum, at 27 cm.
Temperature: Optimal Temperature is around 22C, but can survive anywhere from 15 - 27C. Cooler temperature tropical tanks will also support this fish.
Lifespan: Approximately 10 years.
pH: 6 - 7.5
gH: 9 - 15
Tank Region: Bottom mostly; mid tank during swimming
Gender: Sexing a Weather Loach is rather easy, the male's pectoral fins are longer and thicker, giving the fins a triangular shape. Females have rounder pectoral fins. Males often appear to be standing up on their pectoral fins while resting on the bottom of the tank.
Breeding: Being a cold water fish, it requires cooler water in order to spawn. Breeding is very rarely accomplished in the aquarium.
Colors & Variants: Grey, Brown, Black, Spotted, Golden. Golden Dojo's are not quite albino, more of pinkish color with yellow tint. They are available in most stores, and are sold as "Golden Dojo Loaches". Spotted and Brown are usually called "Common Spotted Dojo" or "Weather Loach" at fish stores.
About: Weather or "Dojo" Loaches have an elongated, eel-like body and five sets of barbels. They have poor eyesight, and use the barbels to find food. If the barbels become damaged there is a high risk of starvation of this fish. For this reason a soft substrate, such as fine sand or soft edged rounded pebbles, should be provided as they are notorious diggers/burrowers. I also do not recommend having this fish in a tank with plants that require burried root systems, as they will dig them up all the time. They will be much better matched with plants that like free roots, such as Java fern, or other rhizome plants.
Weather loaches are scale-less fish and rough rocks such as lava rock should be covered with moss, to make it softer on the fish. Being a scale-less fish, they do not tolerate salt very well. If there is an illness or injury, do not add salt to try to help heal them. Instead, do frequent water changes, as good, clean, water will help them heal much better than salt.
They are a very friendly fish, often eating from their owner's hand and looking for attention. Mine swim around my hand during water changes, looking to be petted.
They are also known to be escape artists, so a tight fitting lid is key with these fish. You may also use a mesh top to make sure your loaches stay in the tank. Glass, mesh, or whatever you may have as lid, make sure there are no holes for the fish to escape from. They have the ability to jump out of the tank and spend the night on the floor.
Weather loaches are very hardy fish, if you do find your loach on the floor, place it back into the tank and add some Stress Coat or other "slime" coating product to help them. They have the ability to store oxygen in their intestines in cases of low oxygenated water, they can survive like this for a few days. Drying out is more of a concern then oxygen. In the wild they will encase themselves in mud to stay wet, and still have enough air to breathe if the stream dries up for a short time. Dojo Loaches can and will secrete a mucus to keep from drying out if they are out of water for some time. When these loaches are in the wild, they are known to "walk" great distances to find another body of water. In Australia they are very often seen walking the roads of Queensland. The sale of Weather Loaches in Australia has been banned due to over population.
In addition, it is not unusual to see your weather loach float up from the tail. This is nothing to be concerned about if the loach can pass out the excess air stored in the intestine; you will see a stream of bubble rise up out of the anus. It is a way of exhaling this stored air. The fish should then be fine. If you notice this happening for extended amounts of time such as days, there may be another problem such as a swim bladder illness.
Being a cold water fish, good tank mates include other dojo loaches (they like to be in groups). Goldfish also make good tank mates, providing you have a tank large enough to support them both. Cooler water tolerant Cory Cats, and cooler temperature tropicals also do well with dojo loaches.
If cared for properly, this fish will bring you many years of joy. They really are a terrific addition to a home aquarium. They will bring fun and few laughs along the way as well.