Question

what are pelenium river​

Answer 1

Explanation:

Pleurobema plenum, the rough pigtoe pearly mussel or rough pigtoe, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. This species is endemic to the United States.

Hope it helps you!

Answer 2

Answer:

did you mean perennial?

perennial rivers are those which have constant streams throughout the year i.e. it never dries out