Cumaceans appear to show little dispersal. Their range is often limited by sand grain size, and other biotic variables. Adults do little to no swimming as they have reduced swimming appendages, and there is no planktonic larval stage. Human activity is responsible for one well-documented example of long distance dispersal: the species Nippoleucon himumensis traveled in ballast water from Japan to the Oregon coast, where it is now a very abundant invasive species (Gerkin 2005).