Ten-year ecological investigation into eight-barbel loach, Lefua tokaiensis (Nemacheilidae, Cypriniformes)
摘要
The ecological characteristics of the eight-barbel loach Lefua tokaiensis Ito, Hosoya, and Miyazaki were elucidated. Ecological field research was conducted at two localities: the montane stream of Houraiji and the Arao River of the Toyo River system in the Tokai region of Japan. The two localities showed high population density of L. tokaiensis, consisting of young-to-aged individuals. Loaches were likely to reproduce and migrate both upstream and downstream throughout year. Their lifespan was over 10 years, and loaches of more than ten generations simultaneously lived together. Growth rates slowed down strikingly with increasing age. The montane stream of Houraiji was suitable for the population of L. tokaiensis. The results of this study contribute to the protection of this endangered species.