Ranchu / Lionhead
A variant of Goldfish (Carassius auratus)
Representative Goldfishphoto — a dedicated image of this exact morph isn't available yet.
Dorsal-less, deeply curved 'king of goldfish' with a full head wen; the Ranchu has a sharper tail tuck than the Lionhead.
Keeper tips for this variant
Lacking a dorsal fin they're poor, slow swimmers — keep gentle flow and shallow, wide tanks, and never house with fast single-tails that will outcompete them for food.