Sinogastromyzon Tonkinensis

Datasheet

General Description

Sinogastromyzon tonkinensis is a poorly-known species in the aquarium trade, endemic to the lower Red River system in Yunnan province, southern China, and northern Vietnam. It possesses unique morphology suited for life in fast-flowing waters, with horizontally-oriented paired fins, a flattened body, and fused pelvic fins forming a sucking disc. The ability to cling tightly to solid surfaces aids in navigating the swiftly-flowing streams it inhabits.

Aquarium Setup

For optimal care, a minimum tank size of 90 litres is recommended for Sinogastromyzon tonkinensis. The setup should include clean, well-oxygenated water with strong filtration and a turnover rate exceeding 15-20 times per hour. A substrate of gravel, sand, or a mix of both, along with rocks, pebbles, and driftwood, mimics its natural environment. Hardy aquatic plants like Microsorum, Crinum, and Anubias species are suitable, but pristine water quality is crucial for its well-being.

Behaviour

This species exhibits very peaceful behavior, best kept with small, non-aggressive tankmates such as pelagic cyprinids, stream-dwelling gobies, rheophilic catfish, and select loaches. Sinogastromyzon tonkinensis is loosely gregarious, and it shows territorial tendencies, particularly around feeding areas. Gender-based aggression may occur, with males potentially more territorial than females, leading to engaging yet rarely damaging interactions.

Feeding and Diet

Sinogastromyzon tonkinensis is a specialized micropredator and biofilm grazer, feeding on small crustaceans, insect larvae, and algae in the wild. In captivity, a diet of live or frozen Daphnia, Artemia, bloodworms, and algae growths on rocks is essential for its health. Sinking dried foods may be accepted, but a regular supply of live or frozen foods is preferable. Maintaining proper feeding and ensuring minimal competition helps weakened specimens recover.

Reproduction & Dimorphism

Reproduction details of Sinogastromyzon tonkinensis remain unrecorded. Male and female individuals can be distinguished by body shape, with males typically slimmer and showing a sharper angle at the base of the pectoral fin. Visual cues from above or below aid in differentiating the sexes, providing insights into potential sexual dimorphism.

Habitat and Distribution

This species is native to swiftly-flowing streams and headwaters in southern China and northern Vietnam, preferring clear, oxygen-rich waters with gravel, rock, and boulder substrates. Sparse aquatic plants, abundant biofilm, and riparian vegetation characterize its habitat. Sinogastromyzon tonkinensis is sympatric with related species like S. multiocellum, S. lixianjiangensis, and S. macrostoma, exhibiting adaptations for life in fast-flowing waters conducive to its unique feeding and locomotive behaviors.