Wavyrayed Lampmussel Spotting!  

While monitoring fish this July, we noticed something interesting on the river bottom: a Wavyrayed Lampmussel attempting to lure a bass! Freshwater mussels have an intriguing lifecycle which includes a larval stage that parasitizes (i.e. infests or lives on) fish. The larval mussel must attach to the gills of a specific fish species to attain nutrition and to hitch a ride upstream. This is where the lure comes in: the adult female Wavyrayed Lampmussel has modified tissue that resembles a small fish. When its host fish, the Smallmouth Bass, gets close, the female mussel expels her larvae. A small number of larval mussels will then attach themselves to the gills of the fish, where they will feed until they develop into juveniles.   

Wavyrayed Lampmussel attempting to lure a Smallmouth Bass in the north Thames River.

The Thames remains one of the most biologically diverse rivers in Canada, and the Upper Thames River watershed is home to at least 80 species of fish, 28 freshwater mussel species and many aquatic species at risk. UTRCA’s biologists monitor freshwater mussels along with other aquatic bio-indicator species such as fish and invertebrates to understand watershed health and whether conditions are improving, deteriorating or stable.

Contact: Erin Carroll, UTRCA Aquatic Biologist