泥鳅 · Oriental Weather Loach

Overview

Misgurnus anguillicaudatus, the oriental weather loach, is adaptable and often buries itself or rises to gulp air. These abilities do not remove its need for good water quality and space. Adults can reach about 28 cm and require relatively cool conditions rather than prolonged tropical temperatures.

Distribution & habitat

Its native range includes Siberia, Sakhalin, Korea, Japan, China, and northern Vietnam. Whether records from Laos represent native or introduced fish remains uncertain. Introduced populations in Europe, Central Asia, North America, Australia, and elsewhere are separate from that natural range.

Typical habitats include shallow, slow river sections, swamps, oxbows, backwaters, and rice fields. Soft sediment, vegetation, submerged roots, and leaves are common. Water depth and clarity fluctuate seasonally, and oxygen can become depleted during dry periods. Weather loaches can supplement respiration through the rear intestine and skin and visit the surface to gulp air.

Aquarium setup

Provide a footprint of at least about 120 × 45 cm for long-term care in a mature indoor aquarium with a secure cover. Use soft sand or fine gravel that permits burrowing. Coarse substrate can obstruct feeding and cause injury. Place rocks and wood securely before adding substrate so digging cannot undermine them, and create plenty of shaded hiding places.

Avoid excessive current while maintaining oxygenation. Guard filter intakes against small fish entering them. General care at about 17.8–23.3 °C is appropriate; extreme tolerance should not become the routine target. Prevent escape and never release fish into natural waters or exposed outdoor systems.

Diet & feeding

Its diet is based mainly on insect larvae, small crustaceans, and similar prey. Offer sinking prepared foods with regular small live or frozen foods such as Daphnia, Artemia, and bloodworms.

Behaviour & compatibility

Weather loaches are generally peaceful. They can live alone but often appear more comfortable and active with conspecifics. Eggs, fry, and very small fishes may still be eaten. Suitable companions should share their temperature needs, be moderately large and active, and use higher parts of the aquarium. Slow fancy goldfish may be disturbed during feeding, so all goldfish forms should not be treated as equally suitable partners.

Sexual dimorphism

Adult females are heavier-bodied and usually slightly larger. Mature males have enlarged pectoral fins, with a thickened second ray forming a rounded structure with a smooth rear edge. Horizontal swellings behind the dorsal fin are also visible from above.

Breeding

Detailed accounts of natural captive spawning are limited, while induced spawning is used in aquaculture and research. The embracing spawning behavior of relatives does not establish a verified home-breeding method for this species.

An all-female lineage in Hokkaido reproduces by gynogenesis: sperm from a related fish stimulates egg development without the ordinary paternal genetic contribution. This is a property of a particular lineage, not the reproductive mode of every weather loach.

Notes

Inspect purchased fish for poor condition and malformed bodies, which can occur in mass-produced stock. Golden, pink, and mottled forms require the same basic care, and hybrids may also occur in trade.

Compared with Misgurnus dabryanus, this species has lower caudal-peduncle crests and normally a dark spot near the upper tail base. Loaches can erect sharp spines below the eyes when stressed; avoid net entanglement and punctures during handling. The weather-related name comes from reports of increased activity around changes in air pressure.