The Demekin is a Japanese variety of goldfish with a full body and telescope eyes. The butterfly tailed variant has a tail that is held forward and spread such that from above it looks like a butterfly's wings. This is a true classical variety: bred to be kept in ponds and bowls and viewed from above (preferably while sipping a fine oolong tea).
These pictures were taken by Alvin Lim of fish he and his friends keep in Singapore.
