| Abstrakt: |
Palaemon sinensis is a landlocked shrimp imported to Japan from China for use as fishing bait. This species was first confirmed in the wild in Japan in 2005, mainly appearing in riverside pools and irrigation canals. The July 2018 flood in western Japan greatly altered streambeds, adjacent riparian, and aquatic zones. However, there is no information on the effects of extreme flood disturbances on populations of this species. In this study, we compared the occurrence of freshwater shrimp before and after the 2018 flood. The results showed that, in the post-flood survey in 2022, P. sinensis appeared in four out of 12 canals but not at the river sampling stations. At the river sampling stations, the amphidromous shrimp Caridina leucosticta was recorded before and after the flood. Other landlocked species, Neocaridina spp., which may show positive stereotaxis to submerged vegetation, appeared after flooding. The present study is the first follow-up survey of the exotic P. sinensis shrimp after the 2018 flood. This species showed relatively low resistance to flooding compared with other freshwater shrimp species. However, irrigation canals were found to be less susceptible to flooding disturbances than rivers as habitats for this species. [ABSTRACT FROM AUTHOR] |
