5| CONCLUSION
Ambient minor cations regulate the expression patterns of specific genes involved in ion transport and thereby affect the hemolymph ionic composition and, ultimately, the survival of H. tridens andM. japonicus. In contrast, in C. dehaani , which lives in more upstream region, ambient minor cations hardly affect the hemolymph ionic composition, likely because of less susceptibility of gene expression to ambient minor cations. The different response to ambient minor cations between euryhaline species could be due to the difference in the microenvironment of their habitats or phylogenetic difference.