Study on the breeding ecology of clouded salamander (Hynobius nebulosus) in Imabari, Ehime Prefecture

Clouded salamander (Hynobius nebulosus), which inhabits in Imabari City, the eastern part of Ehime Prefecture (Japan), is endangered. Measures becomes difficult by the lack of basic ecological information on this species distributed within a limited range of 15km2 makes implementation of appropriate conservation activity difficult. Our objectives of this study were to know the impact of environmental factors on the stability of reproduction of this species. From 2013 to 2015, we investigated on the appearance of adults, the number of egg mass and larvae, and measured environmental factors at 19 breeding sites. We found more than 100 egg mass in both breeding seasons. Therefore, adults were estimated to be about more than 200 individuals. The population in Imabari may have been kept to be deposition total number of during the next 10 years. In addition, as a result of this monitoring, deforestation can easily induce sand at the breeding sites with floods. However, it could be removed by human management until the next breeding season. So, it could be again returned to the appropriate conditions of salamander’s breeding. In other words, though the abandonment of human management for agricultural water supply system breeding sites will disappear. It will lead to the population decline in Imabari. There is a need to preserve both water and terrestrial environments of breeding sites by human management in order to avoid the extinction of the Imabari population.