The Nagoya Daruma pond frog Pelophylax porosus brevipodus is distributed in western Japan and is traditionally divided into two local forms: the Okayama form in the west and the Nagoya form in the east. These two forms are genetically differentiated, but have never been defined taxonomically because their distributions are unclear to date. To complete the distributions and identify the boundary of the two forms, we genetically investigated 16 populations including eight populations located within the unexamined area. We found that the distributional boundary is located within a small area of Hyogo Prefecture where haplotypes of mitochondrial cytochrome b (cytb) and D-loop region corresponding to the two forms co-existed. On the other hand, the polymorphic site of the nuclear gene SOX3 revealed introgression over the boundary into Okayama cytb clade. These results suggest that the two forms were geographically isolated from each other in the past, and secondarily contacted and then accepted one-way introgression. As a next step of the research, taxonomic approach is expected to define the two forms.

To clarify the environmental factors affecting the distribution of the endangered Nagoya Daruma Pond Frog ( ) in paddy levees and fallow paddy fields, we conducted field surveys at 23 study stations in Kurashiki, Okayama, western Japan. Based on the agricultural calendar in the study site, we set five investigation periods of ʻbefore midsummer drainageʼ, ʻduring midsummer drainageʼ, ʻafter midsummer drainageʼ, ʻbefore harvestʼ and ʻafter harvestʼ between July and November 2017. In the paddy levees during the investigation periods between ʻduring midsummer drainageʼ and ʻbefore harvestʼ, the effects of physical environmental factors on the number of frog individuals collected were analyzed with generalized linear models (GLM) . The total number of individuals of .collected in the paddy levees during all the investigation periods was maximum before midsummer drainage, and decreased until after harvest. On the other hand, in the fallow paddy fields, the total number of frog individuals was maximum before midsummer drainage and then decreased until after midsummer drainage, but increased before harvest and then decreased after harvest. The results of GLM indicate that the coverage of plant stems, leaves and litter and coverage of prostrate plants have positive effects 事例研究 2021 年 10 月 18 日受付，2022 年 12 月 4 日受理 早期公開(J-STAGE) J-STAGE