First record of the invasive entocytherid ostracod Ankylocythere sinuosa on the North American red swamp crayfish Procambarus clarkii in western Japan

抄録

In Japan, the invasive entocytherid ostracod Ankylocythere sinuosa was first recorded in 2017, as a symbiont on the invasive crayfish Procambarus clarkii collected in an urban stream in Tokyo, central Japan. In 2022, A. sinuosa was also recorded on P. clarkii and on the Japanese mitten crab Eriocheir japonica, both collected in Shizuoka City, central Japan, but there have been no other Japanese records of A. sinuosa except for these two localities. In this study, we found many individuals of A. sinuosa on P. clarkii collected in an agricultural channel in Okayama City, western Japan. This new record is significant because it is the first from western Japan, approximately 370 km west of the nearest previously known locality, suggesting that this invasive species could be widespread in Japan.