Kudoosis of Marine Fish in Japan

Abstract

Kudoosis of marine fish is caused by the multivalvulid myxosporean parasites belonging to the genus Kudoa (Myxozoa). Muscular kudoosis generally lowers the commercial value of host fish, while brain and pericardial kudoosis may directly affect the health conditions of infected fish. Recent topics on Kudoa septempunctata causing the food poisoning of humans which consume raw olive flounder have presented a new threat to public health. The bi-phasic life cycles of bivalvulid myxosporeans alternating fish and annelid hosts have been revealed, but the lack of knowledge on the life cycles of multivalvulid myxosporeans is hindering the progress of Kudoa research. In this paper, several major kudoosis including K. amamiensis, K. iwatai, K. thyrsites, K. septempunctata, K. yasunagai and K. shiomitsui in Japanese fishes are reviewed from the viewpoint of the disease history, pathobiology, diagnosis, and the control measures.