Natural Treasure of Kōchi Prefecture. In 1971 the breed had reached Tokyo, where a small group of young and avid enthusiasts painstakingly propagated and popularized the variety. The Tosakin Preservation Society (トサキン保存会) was founded a few years later in Aichi prefecture (愛知県）. Husbandry The Tosakin variety requires specific care because of the particular attention placed on achieving the desired tail shape. In order to achieve it's connected, fanned out appearance, the Tosakin has traditionally been kept in shallow, round bowls that allow the tail to fully develop during the fish's first year of life. The low water level and rounded corners of the enclosure allow for lack of excessive upward and downward movement allowing the Tosakin's tail to form correctly and achieve the spread out fan style that is notorious of the variety. In Japan, earthenware bowls traditionally "60cm/24" wide and 18 cm/8" deep with sloping sides" are utilized to house the fish. The bowls are commonly kept outdoors and require no filter. Water quality is kept up through frequent, meticulous water changes. Of the rare few who breed the Tosakin goldfish, many continue to use the original Japanese husbandry methods today. They utilize a wide, shallow water depth, but often opt for the addition of gentle filtration to alleviate the need for excessive water changes to maintain water quality. Sponge filters are commonly used for the Tosakin as the water agitation is minimal compared to other filtration methods. The variety is known for being a clumsy swimmer so excessive water movement must be prohibited to avoid unnecessary stress on the fish. Many consider the Tosakin a delicate goldfish variety, but the breed has proven hardy enough to be kept outdoors all year long like other single and double tail varieties. References External links Varieties of Goldfish in Japan -About Tosakin West Japan Tosakin Preservation Society ( Japanese )