Family: Cyprinidae
A peaceful omnivore cyprinidae from China, the Korean Peninsula, Russia — moderate care.
Acheilognathus macropterus is a Cyprinidae. In the aquarium it stays peaceful. Plan on 19.2–27.5 cm of adult fish at 15–25 °C. Related profiles: Acheilognathus barbatulus, Acheilognathus cyanostigma, Acheilognathus gracilis.
Yes — a classic starter among Chinese native ornamentals. Wide temperature tolerance (15–25 °C), peaceful, omnivorous. The real threshold is tank size: adults reach 27.5 cm, and 275 L is only the start; small tanks never show its full schooling grace.
It's their most fascinating biology: bitterling reproduction depends entirely on mussels — the female inserts her ovipositor into the mussel's gill chamber to lay eggs, which hatch inside the mussel before fry swim free. Without mussels they can't breed in nature. Add one or two Unio or mucket mussels to witness the symbiosis.
Adults reach 19–27.5 cm — the giant of the bitterlings. Juveniles of 2–3 cm are adorable, then grow 8–10 cm a year. Confirm your tank space before buying; don't condemn it to a 60 cm tank for life.
Omnivores leaning algivorous: base pellets plus spirulina wafers, brine shrimp and some bloodworms. The color trinity is strong light (grows the algae they graze), group rivalry (males display to each other), and seasonal temperature rhythm (a cold winter followed by spring warming triggers nuptial dress).
Heat tolerance is limited: sustained 28 °C or higher accelerates metabolism while oxygen drops. Southern summers need shade, extra aeration or a cooler spot. They're a temperate fish, and high summer is their trial.
Six minimum, ten or more for true schooling. Mixed-sex groups show natural displays — males flare nuptial color and chase each other in breeding season. All-male groups color more uniformly; mixed groups behave more richly.
Native stream style: fine sand, river pebbles, clumps of vallisneria or eelgrass. They inhabit the mid-to-bottom layers and love weaving through vegetation. Avoid sharp decor sand — grazing algae and benthic microbes wears the snout raw and invites infection.
A native-tank all-rounder: opsariichthys chubs, zacco, acrossocheilus, medaka and Macrobrachium shrimp coexist harmoniously. Avoid large predators like mandarin fish and snakeheads — gentle mid-sized fish are prey in the food chain.
4–6 years in captivity — a long-lived member of the native tank that stays with you through many seasons. The spring flare of nuptial color is the moment veteran keepers wait for.
Three: that they live only a year (a misunderstanding of wild breeding-season fish — captive lifespans are several times longer); that they're trash fish to keep carelessly (they're actually sensitive to swings, especially heat and ammonia); and that mussels foul the water (healthy mussels are filter champions that also enable breeding — far more help than harm).