Trout are Key to Endangered Mussel’s Survival

The eastern pearlshell  is endangered in Rhode Island.   Should the state do more to protect the native brook trout, and the endangered species of freshwater mussel?  Four years ago Pennsyslvania created a plan for the conservation and recovery of this species.

Targeted habitat restoration activities for trout also create habitat for this endangered mussel. The unique relationship between an endangered mussel and native brook trout may mutually help the recovery of both species while also expanding public fishing opportunities.

The pearlshell  is wholly dependent upon trout for its survival,  because trout act as temporary nurseries for larval (baby) mussels.  As part of their development process, the larvae (glochidia) of the eastern pearlshell must find a temporary home in which to develop into juveniles. they achieve this by using fish as hosts for the glochidia. Gravid (pregnant) female mussels expel thousands of glochidia into the water column and, as they move downstream, the larvae attach to the unsuspecting trout. The glochidia usually attach to the gills, where there is a lot of surface area. After temporarily parasitizing the fish, the hitchhiking glochidia quickly metamorphose (grow and change) into juvenile mussels, which drop off the fish and settle into the river or stream bed.

Pennsylvania’s official fishing and boating magazine  July/August 2013.  Read more here



1 comment to Trout are Key to Endangered Mussel’s Survival

  • brian o'connor

    When leaving their host fish, the baby mussels must land in clean gravel in order to survive. Fine sediment does not allow survival.