Found possibly before Delaware and Potomac rivers, also recorded from Virginia (Ref. 4639). Dredging of rivers (e.g. Hudson) greatly increases siltation thus reducing food availability during the onset of exogenous feeding of the larvae. Dams block access to spawning sites of many rivers. Listed under the U.S. Endangered Species Act; the Hudson R. stock has increased in number and now considered stable but as the stock recovers, poaching may become a problem. However, the Connecticut R. stock has not increased markedly and the southern populations continue to be threatened with extinction (Ref. 38308). Also Ref. 11975 ,93252, 27549.

Status of threat: endangered; status declined since 1989. Criteria: 1,2 (http://fisc.er.usgs.gov/afs/) (Ref. 81264).