Sarcocheilichthys parvus

Very — the honest workhorse of Chinese native fish. Gentle, unfussy, broadly adaptable at routine 18–26 °C and pH 6.5–7.5. The real threshold is tank size: adults reach 12–17.6 cm with a 372 L floor — larger than most keepers expect. It's the classic 'stream-tank background' species, decently sociable; keep four or more.

372 L is the floor; 400–600 L in practice. It swims actively at a medium-large size and looks cramped and dull in tanks under 200 L. Recommended scape: creek-tank style — cobblestone, fine sand, gentle current, generous oxygen. This matches its native Chinese hill streams and shows the silvery body with dark lateral stripe at its best.

Unfussy omnivore: algae, detritus, small invertebrates, prepared foods all taken. Quality sinking pellets and wafers as staple with algae wafers and frozen bloodworms in rotation. Its sub-terminal mouth feeds at the bottom — the clearest niche distinction from same-size upper-water fish like zacco. The more varied the diet, the steadier the condition.

Gentle native fish of matched size are ideal: gudgeons (Abbottina), Squalidus, small Microphysogobio, small barbs. Three notes: matched sizes (gaps invite suppression or predation), consistent flow needs (all creek fish), and restrained density. Avoid predators (mandarinfish, snakeheads) — this species' gentleness has no floor, and its escape reflex lags half a beat behind danger.

Three usual causes: undersized or crowded tank (space and density stress), substrate too dark (its tone shifts with the bed — pale sand shows silvery-white), or poor condition (a signal of disease or water issues). The first two are management — adjust the environment. If accompanied by fasting and isolation, test water before hunting pathogens.

Yes — the standard creek-fish affliction. In nature it inhabits mountain torrents where jumping crosses falls and escapes predators. A lid is mandatory; unlike tetras that 'jump but not high', an adult of this species clears standard tanks with real force. Water changes, fright, and harsh light all trigger.

Hard at home. It's a bottom spawner needing stream simulation: cooler water (16–20 °C) to trigger, high oxygen, sandy-gravel substrate. Modest egg numbers (dozens to a few hundred), eggs are demersal and adhesive in rock crevices. Fry start on rotifers or superfine powder. Documentation is scarce and successes come from native-fish diehards iterating — don't buy it with breeding as the goal.

Three similar mid-size creek bottom fish with telling details: this species carries a clear black lateral stripe (gill cover to caudal peduncle) and a slim build; gudgeons (Abbottina) are stockier with blotches but no stripe; Squalidus are smaller, entirely silvery, unmarked. Niches overlap and they mix fine, but this species schools slightly better and shows slightly better — why it's risen lately.

Yes, recommended. It's a creek fish from oxygen-saturated water and demands more oxygen than pond-type species. Tolerance is decent (short hypoxia won't kill it), but chronic oxygen shortage shows as poor appetite, dull color, and disease-proneness. Standard setup: filter output that agitates the surface, or an added air stone — for creek fish, 'clean enough' and 'oxygenated enough' are equally important.

Five to eight years is normal. Not long-lived among natives, but its virtue is hardiness and a stable display window. It's the fish that's 'barely noticeable but whose absence breaks the tank' — a complete stream scape needs a mid-size bottom fish like this, and it's currently one of the easiest to source.