大鳞副泥鳅 · Large-scaled Loach

Overview

Misgurnus dabryanus, the large-scaled loach, is frequently sold among weather loaches under the wrong name. It favors relatively cool, slow-water conditions and spends time buried in the substrate. High crests on the caudal peduncle and the absence of a dark tail-base spot help identify it.

Distribution & habitat

The natural range covers the middle and lower Yangtze and Pearl systems in mainland China and several smaller drainages in Taiwan. Records from the Russian Amur, Japan, and other regions include introductions rather than native populations.

It inhabits shallow, slow river sections, swamps, oxbows, backwaters, and rice fields. Soft mud or silt supports vegetation, roots, branches, and leaf litter. Seasonal changes affect water depth and clarity, while dry conditions may leave stagnant, oxygen-poor water. Loaches of this group can supplement breathing through the rear intestine and skin and rise to gulp air.

Aquarium setup

Provide a footprint of at least about 90 × 30 cm and soft sand. Coarse gravel can obstruct burrowing and feeding or cause injury. Install smooth rocks and wood securely before adding substrate to prevent excavation from destabilizing them. Include ample hiding places and shade; subdued light is suitable.

Avoid strong current but retain adequate oxygenation. Protect filter intakes against small specimens entering them and use a close-fitting lid, especially while newly introduced fish settle.

Diet & feeding

The diet is based chiefly on insect larvae, small crustaceans, and similar prey. Sinking dry food is accepted, but regular small live and frozen foods such as Daphnia, Artemia, and bloodworms should add variety.

Behaviour & compatibility

It is generally very peaceful, though eggs, fry, and extremely small fishes may be eaten. Individuals can live alone but usually seem more comfortable and active in a group. Choose temperature-compatible, moderately large and active companions using higher water layers.

Not every goldfish form is a suitable partner. More agile varieties may work, whereas slow fancy forms can be disturbed when the loaches are feeding.

Sexual dimorphism

Mature females are usually heavier-bodied and slightly larger. Adult males have enlarged pectoral fins with thickened rays.

Breeding

Hormonal induction is used in research and aquaculture, but detailed accounts of natural captive pairing are limited. A reproductive pattern resembling related weather loaches is possible; their age at maturity, breeding season, and larval development times should not be transferred directly to this species.

Notes

It is often labeled or shipped with Misgurnus anguillicaudatus. Beyond the high peduncle crests and missing tail-base spot, locality and shipment information can help establish identity. The two apparently hybridize in some areas where they coexist.

Hardiness and reproductive potential facilitate human-assisted spread, so prevent escape and never release unwanted fish. Loaches can erect sharp spines below the eyes when stressed; handling should avoid net entanglement and puncture injuries.