Ichthyomyzon castaneus Girard, 1858
member of the Lamprey Family (Petromyzontidae)
Sunrise River, Chisago County, Minnesota 6 May 1988
Chestnut Lamprey and Suckermouth Minnow
In a Name?
Do They Live?
Chestnut lampreys live in certain large streams and small rivers of the Red, St. Croix, and lower Mississippi river systems. Adults can be found in just about any habitat within these streams, where they are often found attached to the sides of their prey (see "What do they eat"). The larvae (called ammocetes, pronounced "ammo-seats") bury themselves in soft silt and muck in areas of quiet water with some aquatic vegetation.
Big Do They Get?
Do They Eat?
The long-living larvae (called ammocetes, pronounced "ammo-seats") filters tiny algae (desmids and diatoms) and protozoa (ameba, etc.) from the soft sediments and water just above them. As adults, chestnuts attach themselves to the sides of various fishes, including a variety of suckers, catfishes, and sturgeons. They chew a hole into the flesh of the host fish, consuming a small bit of its muscle and a lot of body fluids.
Do They Reproduce?
We do not know how long it takes for the eggs (which are really embryos) to hatch. The newly hatched ammocetes, (pronounced "ammo-seats") drift downstream to softer bottoms and burrow into the muck. They eat, grow, and develop over several years (maybe 5-7) before they metamorphose (change into) adults.
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Photographs by Konrad P. Schmidt
Text by Nicole Paulson & Jay T. Hatch in cooperation with
the Minnesota Department of Natural Resources' MinnAqua Aquatic Program
This page developed with funds from the
MinnAqua Program (Minnesota Department of Natural Resources, Division of Fisheries)
Sport Fish Restoration Program (Fish and Wildlife Service, US Department of the Interior)
Maintained by Jay T. Hatch
General College and James Ford Bell Museum of Natural History
University of Minnesota, Minneapolis/St. Paul
Last updated 23 October 2002