Rainbow Trout / Niji Masu

2010/11/17 Rainbow Trout / Niji Masu

Nijimasu [jp] / Raibow Trout
Oncorhynchus mykiss (Walbaum, 1792)


Rainbow trout was first introduced to Japan in 1877 from the hatchery in Mounta Shasta, California. In 1880, already 20 thousands eggs were successfully hatched near Tokyo. This fish was destined to become the popular fish. Today, the word masu or trout almost means rainbow trout. You can find rainbow trout in any game water nationwide.

Habitat of Native Run Fish

Wild rainbow as steelhead is only available in the northern most island of Hokkaido where it is considered invasive species.  Where in the island of Honshu offering a river without a dam blocking its reproduction cycle of going back and fourth between cold stream and cold ocean, they flourish and some rivers in Aomori were known to be such water.