Silent Invasion

One week ago Arya-san, Sagae-san and I went to the rice fields to take samples. We went there using Sagae-san's car. When we got there, we separated to three different places. We collected several Mud snail and Kawanina snail. There is one place where conditions are deeper than others. There we found several creatures such as Kawanina snail, Mud snail, Fish, and the most interesting is large Crayfish. Crayfish are predators in aquatic ecosystems. Sometimes it benefits the aquatic ecosystem, but sometimes it can damage because it can eat other beneficial organisms. This case often occurs in the entry of an organism into a new place to control pest organisms. Unfortunately, invasive organisms dominate and eliminate some native organisms. Such as the case with the invasive species Harmonia axyridis which dominates in America.