横带沙鳅 · Green Tiger Loach

Overview

Syncrossus hymenophysa is an active, boldly barred loach that needs both substantial housing and conspecific company. Attractive juveniles grow into fish with social hierarchies and potentially difficult interactions with unsuitable tankmates.

Distribution & habitat

Records span Sumatra, Sarawak and West Kalimantan on Borneo, and the Pahang and Perak systems of Peninsular Malaysia. Continued survival of the peninsular populations is uncertain, while reports from Java remain doubtful.

Habitats range from upland streams to major river channels and lakes. Submerged branches, roots, and logs are commonly used as cover. Fish enter flooded ground during the rainy season to feed and reproduce. Seasonal changes in depth, current, turbidity, and temperature mean a collection site does not represent constant year-round conditions.

Aquarium setup

Provide a base around 150 × 45 cm or larger. Combine sand or fine gravel with rounded rocks and wood to create several sheltered spaces. Subdued lighting and shade-tolerant plants suit the arrangement. Remove sharp objects, block holes that could trap exploring fish, and fit a secure lid.

Strong oxygenation and moderate circulation are useful; violent flow is unnecessary. The biological filter must be mature before introduction. Keep organic waste under control and replace approximately 30–50% of the water weekly.

Diet & feeding

This genus tends toward animal foods but also takes plant material. Suitable aquarium offerings include good dry foods, worms, brine shrimp, cucumber, and blanched spinach. Small amounts of chopped earthworm or mixed gel food can broaden the menu. Soft plants may be grazed. Snail predation should not be treated as a guaranteed pest-control service.

Behaviour & compatibility

Five or six is a minimum group, with ten or more preferable where housing permits. A lone fish may become withdrawn or aggressive toward similar fishes. Keeping only two or three can leave subordinate individuals subject to repeated attacks and unable to feed normally.

Avoid very small, slow, and long-finned species, which can be intimidated or have their fins bitten. Active open-water cyprinids are more promising companions. Even robust loaches require observation because successful combinations elsewhere do not exclude aggression from particular individuals.

Sexual dimorphism

Mature females are expected to be more robust and possibly larger than males. Other dependable external distinctions are unclear.

Breeding

Wild fish use inundated areas for reproduction during the rains. Reliable aquarium breeding has apparently not been achieved, and a routine egg-scatterer protocol should not be assumed appropriate.

Notes

Useful identification clues include a dark dorsal-fin spot, twelve to fifteen vertical bands edged in blue, and the absence of tiny dark markings on the lower body.

Related loaches can fade temporarily during rank contests and make clicks when excited. Their erectable spines beneath the eyes may snag netting or puncture skin. Progressive weight loss in newly acquired fish needs attention, but the symptom itself does not establish a single cause.