 The freshwater pearl mussel grows extremely slowly, inhaling water through exposed siphons, and filtering out tiny organic particles on which it feeds.It is thought that in areas where this species was once abundant, this filter feeding acted to clarify the water, benefiting other species which inhabited the rivers and streams.Maturity is reached at an age of 10 to 15 years, followed by a reproductive period of over 75 years in which about 200 million larvae can be produced.