BIO 210


Silver Lamprey go through two different nutritional stages in their life's.  A Silver Lamprey begins its life as a non-parasitic ammocete, but after Silver Lamprey go through a metamorphosis to their adult forms they become parasitic.

 After Silver Lamprey hatch from their fertilized eggs they enter the ammocete stage of their life.  Ammocetes are the non-parasitic form of Silver Lamprey.  They remain in this non-parasitic form for 4 to 7 years before going through a metamorphosis to their adult form(Ichthyomyzon unicuspis, Smith 1985, COSEWIC).  Ammocetes live in the soft muck and sand in the rivers where they were born, there they filter-feed microscopic food (Ichthyomyzon unicuspis, Smith 1985, COSEWIC, Silver Lamprey, The Native Silver Lamprey).  The microscopic food that ammocetes feed on include algae. drifting plankton and detritus(Smith 1985, Ichthyomyzon unicuspis).

 After 4 to 7 years in the ammocete form the lamprey go through a metamorphosis developing eyes and teeth.  After they go through the metamorphosis Silver Lampreys are considered to be in their adult form and begin their parasitic stage.  Parasitism is an interaction between two organisms in which one organisms benefits, while the other organism, commonly called the host is harmed(Hickman 2012).  Parasitic adults move from the rivers where they were born to large bodies of water where large fish are located (Smith 1985).  Silver Lamprey use there teeth and large sucking mouth to attach to host fish and bite a hole in the hosts skin(The Native Silver Lamprey, COSEWIC, Ichthyomyzon unicuspis).  They then remain attached to the host and feed off their  flesh and bodily fluids.  Lampreys often change there host to a whitish color from blood lose, but usually do not kill their host.  By killing their host they lose their source if nutrients (Ichthyomyzon unicuspis). Silver Lamprey a can feed off of a variety of different host species including

Whitefish (Coregonus clupeaformis)

Smelt (Osmerus mordax)

Pike (Esox lucius)

Brown Bullhead(Ictalurus nebulosus)

Rock Bass (Ambloplites rupestris)

Walleye (Stizostedion vitreum)

Lake Sturgeon (Acipenser fulvescens)

Property of Wisconsin DNR

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