The ito, commonly referred to as "phantom fish," are significant members of the freshwater ecosystem in Japan, predominantly found in Hokkaido and the Northern Territories, with their breeding activities only being confirmed in a few rivers. The environmental impact of local government road construction near their spawning areas has led to concerns about sediment influx affecting the survival of their fry. Despite their endangered status, the spawning season in April offers a rare opportunity to witness the striking behavior of male ito competing for female attention, displaying vibrant red colors during this period.
During the spawning season, a male ito's body, apart from its head, turns a vivid red, indicating their breeding readiness and fervor. The intense battles between rival males, each over a meter in length, for the affection of a female depict the challenges these scarce fish face in their natural habitat. The disruptions caused by increased sedimentation near their spawning grounds due to the construction activities upstream highlight the ongoing threats to the survival of ito in the wild. Despite such challenges, the remarkable observations made by an Asahi Shimbun reporter provide a glimpse into the intricate mating rituals and survival struggles of these critically endangered fish species.