During the Summer of 2015, a rare species was found in a tributary of Walnut Creek that has not been found in the Des Moines River basin since the 1980’s. While conducting stream assessment in the creek, Polk SWCD and Dallas SWCD interns found what looked to be a deceased species of lamprey. After further investigation, using images taken, the DNR identified the species as a Chestnut Lamprey.
Chestnut Lampreys move into small tributaries during spawning. They search for rock habitat to lay their eggs in and then die. It is possible that the found lamprey had recently spawned and that is why it was found deceased. The eggs hatch into larvae that filter feed for several years in the small streams. The larvae then transform into parasitic adults and move downstream to feed on larger fish.
In partnership with the DNR, Polk SWCD staff Amanda and John have begun searching the tributaries of Walnut Creek for evidence of a population of Chestnut Lampreys. See photos of the first adventure below. Unfortunately, no lampreys were found this time! Stay tuned to see what they find!