In eastern Hokkaido, the spawning season for ito, a large freshwater fish in Japan and a member of the salmon family, takes place in April. However, despite being one of the largest freshwater fish in Japan, the breeding of ito is only confirmed in a few rivers, mainly in the northernmost part of Hokkaido and the Northern Territories. The Environment Ministry of Japan has classified ito as endangered due to the high risk of extinction in the wild in the near future.
Recently, an Asahi Shimbun reporter had a unique opportunity to witness a fierce battle between two male ito, both over a meter in length and red with ardor, competing for the attention of a female during the spawning season. The spawning area of ito faced challenges due to local government road construction upstream that resulted in a deluge of sediment, potentially affecting the hatching of the fry. This led the reporter to question how the spawning process would unfold in such conditions.
As the reporter observed a male and a female pair of ito, a male rival approached in the meandering current, leading to a dramatic showdown between the two males. The battle unfolded in shallow water with the two males fiercely fighting for dominance, while the male paired with the female tried to prevent contact between his rival and the female. The intense struggle was accentuated by the exposed bodies of the males, lasting for several dozen seconds as they battled near blooming yellow fuchsia on the shore, a plant known as chiraiapappo by the indigenous Ainu people.