|This species daphnia
is native to Africa and Australia and may have come in with shipments of Nile
perch to Texas where it was first found in Texas in 1990. It has since spread
to 56 reservoirs in 15 other states. The
impact of this species is not yet known, but it has the potential to become
the dominant zooplanktor because of its ability to avoid predators because of
its numerous spines.