1 kinds · tap one for a closer look
Peaceful and active at dusk.
This one is best kept on its own, or with its own kind.
Peaceful and active at dusk. Best in a cool tank with sand and with other coldwater fish; keep lids tight.
Check your local laws. EU: listed in Annex II of the Habitats Directive (92/43/EEC), so sites where it lives must be managed for it; nationally threatened in Austria, Czechia, Denmark, Germany, Hungary, Slovakia, Slovenia and Switzerland. England: the 2003 schedule of fish that may not be kept or released without a licence names the weather fish, and since 2015 releasing any fish into inland waters needs an Environment Agency permit. US: Vermont treats any fish not on its restricted or unrestricted lists (Misgurnus is on neither) as prohibited without a permit. No US federal listing found; Australia not confirmed. Check the rules where you live before you buy one, and never release it into the wild.
Sinking pellets, earthworms, bloodworms.
Tap a food to see what it is.
Common problems. Tap one to see the signs. This is a guide, not a diagnosis.
Seasonal spawner · Hard
Spawns from early spring: the female leads the male into dense plants, where he wraps around her in a complete ring as eggs are released. It matures at 2-3 years. Conservation hatcheries breed it by hormone injection and stripping, incubating eggs at about 18 °C.
Natural pairing in spring from a group.
Large pond or tank with soft vegetation and winter cooling.
Cold winter followed by a warm spring rise.
Very high fecundity, about 100,000-150,000 eggs per female, laid among dense plants. Hatch time not found; newly hatched fry have external gills for 10-12 days.
Fry hatch in 4-7 days and need infusoria then brine shrimp.
A native European loach of muddy, weedy backwaters and ditches. It has declined or vanished across much of its range, is listed in Annex II of the EU Habitats Directive and is on the Red Lists of many countries; it is rarely available.
Linnaeus described this loach in 1758 as Cobitis fossilis. It earned the name weatherfish because it becomes restless when air pressure changes before storms. It can breathe air and survive in oxygen-poor water.
First described by Carl Linnaeus in 1758. Named for 'fossilis' means 'dug up', referring to it living in mud.
11 facts checked with sources
Valid. No Seriously Fish profile exists.
Eschmeyer's Catalog of Fishes (online, updated 21 Sep 2026): Misgurnus fossilis · FishBase: Misgurnus fossilis summaryLegacy has no family.
FishBase: Misgurnus fossilis summaryAll TL. Max 30 cm (record female 30.7 cm, Netherlands); common length 15 cm; German wild broodstock females averaged about 20 cm. No aquarium-based figure exists to compare.
FishBase: Misgurnus fossilis summary · Schreiber et al. (2018) Reintroduction and stock enhancement of European weatherfish (Misgurnus fossilis) in Rhineland-Palatinate and Hesse, Germany. Knowl. Manag. Aquat. Ecosyst. 419: 43 (peer-reviewed)Legacy 8-22 °C sits inside FishBase's 4-25 °C (Ref. 1672 is an aquarium atlas). A coldwater fish; no unheated-tank range from Seriously Fish.
FishBase: Misgurnus fossilis summaryNocturnal; burrows 20-30 cm into mud during droughts and hard frosts (FishBase).
FishBase: Misgurnus fossilis summaryCatalog of Fishes: 'Europe and western Asia'. Global IUCN Least Concern, but threatened nationally in many countries.
FishBase: Misgurnus fossilis summary · Schreiber et al. (2018) Reintroduction and stock enhancement of European weatherfish (Misgurnus fossilis) in Rhineland-Palatinate and Hesse, Germany. Knowl. Manag. Aquat. Ecosyst. 419: 43 (peer-reviewed)No source for the legacy claims (male smaller with thicker pectoral fin, female larger). FishBase notes males lack the lamina circularis that most cobitid males have.
FishBase: Misgurnus fossilis summaryLegacy says captive-bred stock is sold in small numbers in Europe; no source found for that trade.
FishBase: Misgurnus fossilis summary · Schreiber et al. (2018) Reintroduction and stock enhancement of European weatherfish (Misgurnus fossilis) in Rhineland-Palatinate and Hesse, Germany. Knowl. Manag. Aquat. Ecosyst. 419: 43 (peer-reviewed)Legacy 'up to 100,000' is the low end of FishBase's fecundity. Legacy '4-7 days' hatching is unsourced.
FishBase: Misgurnus fossilis summary · Seriously Fish: Misgurnus dabryanus (cites Kottelat & Freyhof 2007 on M. fossilis)The 'restless before storms' legend is widely repeated but no species-specific source was found (Seriously Fish gives it only for the pond loach's common name). 'Rarely seen in the trade' is plausible but unsourced.
Schreiber et al. (2018) Reintroduction and stock enhancement of European weatherfish (Misgurnus fossilis) in Rhineland-Palatinate and Hesse, Germany. Knowl. Manag. Aquat. Ecosyst. 419: 43 (peer-reviewed)England: whether the 1998/2003 Order is still in force after the 2015 Regulations was not confirmed (the page fetched is the 'as made' text). Vermont: inferred from the default clause plus the unrestricted Cobitidae genera list, which leaves out Misgurnus. Legacy text was 'Protected in several EU states'.
Schreiber et al. (2018) Reintroduction and stock enhancement of European weatherfish (Misgurnus fossilis) in Rhineland-Palatinate and Hesse, Germany. Knowl. Manag. Aquat. Ecosyst. 419: 43 (peer-reviewed) · INBO (Research Institute for Nature and Forest, Flanders): Feasibility study (re)introduction of European weather loach (government) · UK SI 2003/25: Prohibition of Keeping or Release of Live Fish (Specified Species) (Amendment) (England) Order 2003, art. 2 (as made) · UK SI 2015/10: Keeping and Introduction of Fish (England and River Esk Catchment Area) Regulations 2015, explanatory note · 12-077 Code Vt. R. 12-010-077-X: Vermont list of prohibited, restricted and unrestricted fish species (via Cornell LII)