越南华吸鳅

Overview

A rarely traded Red River hillstream loach, Sinogastromyzon tonkinensis is peaceful and rather retiring. It needs a mature, clean, highly oxygenated stream-style aquarium. Mouth width and barbel structure are particularly useful when separating it from similar species sharing the drainage.

Distribution & habitat

The type locality is Lai Chau in northern Vietnam. Known records concern the Red River system in Yunnan, China, and northern Vietnam, apparently its only drainage. It inhabits clear, oxygen-rich streams and headwaters, including riffles and runs, with a probable preference for shallow areas. Gravel, rocks, boulders, and bedrock support rich biofilm; submerged plants are sparse but bankside vegetation is often substantial.

A January 2009 observation from the Menyejiang, a Lixianjiang tributary in Puer, Yunnan, recorded 17 °C, pH 8.8, and approximately 2 dGH. Those values describe one sampling event rather than a recipe that must be reproduced exactly.

Aquarium setup

Provide a footprint of at least about 75 × 30 cm. Substantial filtration with supplementary pumps or aeration should support circulation around 15–20 tank volumes per hour or more while maintaining high oxygen. Torrential conditions are unnecessary. Use sand or gravel with varied smooth stones, optional roots and branches, and robust attached plants.

Introduce fish only into a biologically mature, stable system and prevent organic waste buildup. Fit the lid securely against glass-climbing escapes. Long-term temperatures around 15–22 °C are appropriate, with extra attention to oxygen during brief warmer periods.

Diet & feeding

Sinogastromyzon browse biofilm for small crustaceans, insect larvae, and other invertebrates, also consuming some algae. Sinking preparations may be accepted, but daily live or frozen Daphnia, Artemia, bloodworms, and similar foods are important. Retain mature grazing surfaces.

Where attached growth is insufficient, cultivate algae-covered stones in a separate brightly lit container and rotate them into the main aquarium. Severely wasted individuals can be difficult to restore and need continuously accessible food with little competition.

Behaviour & compatibility

Avoid much larger, aggressive, territorial, or strongly competitive fishes. Small open-water species, stream gobies, and some rheophilic catfishes may work if they also suit cool, flowing water. Assess other loaches individually.

Maintain a loose group of at least four. Some individuals defend good feeding patches, but injuries are uncommon. A possible link between territorial intensity and sex remains uncertain. Group keeping may also reduce prolonged hiding.

Sexual dimorphism

Viewed from above or below, males tend to be slimmer and have a sharper junction between the pectoral fin and head. Females have a fuller outline and a rounder junction.

Breeding

Aquarium reproduction has not been recorded.

Notes

Two pairs of relatively long, thin barbels at the mouth corners and a mouth spanning about 39.8–48.3% of head width help identify this species. Sinogastromyzon multiocellum has thicker barbels and a narrower mouth. Sinogastromyzon lixianjiangensis and Sinogastromyzon macrostoma have tiny barbels, with the latter possessing a much wider mouth.

Regular dorsal blotches and a tail stalk longer than deep provide further clues. In the genus, a flattened front body, expanded paired fins, and joined pelvic fins enable attachment to rocks. Crawling over and under stones is more effective than open-water swimming.