Ranchu Goldfish

About

The ranchu goldfish (Carassius auratus var. ranchu) is one of the most recognizable and beloved fancy goldfish varieties, developed over centuries of selective breeding in East Asia and sometimes called the 'king of goldfish' in Japan. Its defining features are a deep, egg-shaped body, an arched back with no dorsal fin, and an elaborate head growth called a wen that develops as the fish matures, eventually framing the face in fleshy lobes. The tail is typically short and downturned, giving ranchu a distinctly waddle-y, unhurried way of moving through the water. Because they have no dorsal fin and carry so much body mass, ranchu are genuinely poor swimmers compared to slim-bodied goldfish, and that has real implications for keeping them well. They do best in a species-only setup or alongside other fancy goldfish of similar body type. Faster tankmates will consistently out-compete them for food. Strong currents also stress them, so gentle filtration is worth prioritizing. Feeding takes a little care too, since their body shape makes them prone to buoyancy issues if they gulp too much air at the surface. With attentive husbandry, ranchu are peaceful, long-lived fish that reward patient keepers with a lot of personality.