Guides

Goldfish

Ryukin Goldfish (Carassius auratus)

The ryukin is a deep-bodied, hump-backed fancy goldfish that grows to 15–20 cm: hardy, friendly and long-lived, but it needs a big, cool, heavily…

Goldfish are opportunistic omnivores with a long gut. The right pellets, greens, and portion control prevent the classic bloating problems.

Not every fish wants 78°F — unheated rooms suit goldfish, minnows, and hillstream specialists with the right setup.

A fish stuck at the surface or on the substrate often has swim bladder distress — diet and water quality fix many cases.

A velvet-black telescope-eyed fancy goldfish that needs soft décor, gentle tank mates, and cool, clean water.

A fancy goldfish with a distinctive raspberry-like hood — calm, coldwater-friendly, and happiest in spacious, well-filtered aquariums.