The Oranda is one of several varieties of what is commonly known as the Goldfish,
Carassius auratus auratus. The goldfish originally came from parts of Asia, Japan,
and China but now enjoys worldwide distribution due to controlled breeding programs.
Though it resembles the Veil Tail varieties, the Oranda is notable for its "hood"
that covers its head. Some Orandas have warty growths covering the entire head,
including the opercula.
 
The Oranda Goldfish is born without its signature head-growth. The growth begins to
thicken and fold three to four months after hatching. It may take up to two years for
the head-growth to fully develop. The development of the hood is affected by a number
of factors, including the quality of water in which the fish lives and its diet. A stable, clean aquarium
or pond and a protein-rich diet will enhance the development of the head-growth.