Weather Loach
Misgurnus anguillicaudatus
A hardy coldwater loach said to grow restless before weather changes.
| Difficulty | Beginner |
| Min. Tank Size | 110 L |
| Temperature | 10.0–24.0 °C |
| pH Range | 6.5–8.0 |
| Max Size | 25.0 cm |
| Lifespan | 7-10 years |
| Diet | Omnivore |
| Temperament | Peaceful |
Overview
The Weather Loach (Misgurnus anguillicaudatus) is a hardy coldwater loach said to grow restless before weather changes. It is one of the most recognisable members of the loaches group kept by Australian aquarists, valued for its appearance, manageable adult size of around 25.0 cm and its peaceful nature.
This guide covers everything you need to keep the Weather Loach successfully - ideal tank size and setup, water parameters, diet, suitable tank mates, breeding, how to tell males from females, and the health problems to watch for. Rated Beginner to care for, it can live for roughly 7-10 years when its needs are met.
Natural Habitat & Origin
Loaches come from the streams, rivers and floodplains of South and South-East Asia, where they forage along the bottom among rocks, roots and leaf litter. Many are scaleless or fine-scaled, which makes clean, stable, well-oxygenated water especially important.
Understanding where a fish comes from is the shortcut to keeping it well: matching the temperature, water chemistry and amount of cover it evolved with is far more effective than fighting against its nature.
Tank Size & Aquarium Setup
Provide a minimum of 110 litres for the Weather Loach. Because it is a shoaling fish kept in groups, floor space and swimming length matter more than height.
Use a secure, well-fitting lid (this species can jump, and labyrinth fish also need a warm layer of air above the water).
Provide smooth substrate plus plenty of caves, pipes and tangled wood, as loaches feel safest with lots of hiding places to dart into.
Mature, well-cycled biological filtration is essential before adding any fish. Match the filter's flow to the fish - moderate for most, stronger and more oxygenated for hillstream and riverine species.
Water Parameters
Keep the Weather Loach in stable water at 10-24 °C with a pH of 6.5-8.0. It is adaptable across a moderate range, so stability matters more than hitting an exact number.
Test your water regularly: ammonia and nitrite must always read zero, and nitrate should be kept low (ideally under 20-40 ppm) with routine partial water changes. Sudden swings in temperature or chemistry cause far more illness than water that is slightly 'wrong' but stable, so always dechlorinate and temperature-match new water.
Diet & Feeding
The Weather Loach is an omnivore and an easy feeder. A quality flake or micro-pellet forms a good staple, enriched several times a week with frozen and live foods such as bloodworm, daphnia and brine shrimp for colour and condition.
Feed small amounts once or twice a day - only as much as the fish clears in a minute or two - and consider one fasting day a week. Overfeeding is the single most common cause of pollution and disease in home aquariums.
Temperament & Tank Mates
The Weather Loach is an excellent peaceful community fish. It mixes happily with other calm species that share its temperature (10-24 °C) and pH (6.5-8.0) needs, are too large to be eaten, and are not large enough to eat it.
Keep it in a small group rather than singly; it is a social fish that is shyer and less active when kept alone.
Breeding
The Weather Loach is rarely bred in home aquariums; commercial stock is typically farm-raised with hormones, so home spawning is considered very difficult.
Even if you do not plan to breed it, understanding this behaviour helps you recognise it in the tank and respond appropriately - for example by adding cover for fry or by giving a guarding pair some space.
How to Tell Males from Females
Many loaches are very difficult to sex visually; females are often rounder-bodied when mature, but reliable differences are subtle and vary by species.
Common Health Problems
Like most aquarium fish it is susceptible to white spot (ich), fin rot and fungal infections, almost always triggered by stress or poor water quality. Scaleless and sensitive, loaches react badly to poor water and to copper-based or full-dose medications - treat at half strength. Quarantine new arrivals for 2-4 weeks to keep your main tank disease-free.
Prevention is far easier than cure: keep water pristine, avoid overstocking and overfeeding, quarantine new arrivals for two to four weeks, and watch daily for early warning signs such as clamped fins, loss of appetite, flashing (rubbing on objects) or laboured breathing. Caught early, most problems are very treatable.
Is the Weather Loach Right for You?
The Weather Loach is a rewarding choice for beginners and experienced keepers alike, as long as you can provide at least 110 litres, water at 10-24 °C and pH 6.5-8.0, the right diet and a proper group of its own kind.
Get those basics right and you will enjoy a healthy, colourful Weather Loach for around 7-10 years. For tank planning, try our free aquarium tools, and browse our fish, plant and disease guides to build the perfect community.