The Tamasaba or Sabao is an uncommon Japanese variety of goldfish with a body shaped similar to the Ryukin and a very long, flowing, single tail that is similar to that of a mackerel, hence its other name, Mackerel Tail. This attractive and strong goldfish variety makes a very suitable pond fish and aquarium fish, and comes in solid red and deep red and white colors. It withstands the cold very well. The Tamasaba originated from the Yamagata Prefecture in northern Japan, hence it is also known as Yamagata Kingyo or Yamagata Goldfish.[1]
References
^ Johnson, Erik L., D.V.M. and Richard E. Hess Fancy Goldfish: A Complete Guide to Care and Collecting, Shambhala Publications, Inc., 2001 - ISBN 0-8348-0448-source:wikipedia