These animals are infected by parasitic barnacles of the genus Sacculina, which cause sterilization and loss of the ability to regenerate. A migratory species of these animals has been devastated by the invasive yellow crazy ant. The sex of these animals (10[1])can often be determined from the shape of the pleon, which in males is more narrow and triangular. In a sexually dimorphic species of these animals, males wave a grossly enlarged appendage to attract females. A species of these animals that's native to Japan has the longest leg span of any arthropod. Several unrelated groups of decapods have adopted the body shape of these animals in the phenomenon of carcinization. The ■END■