DNR asks lakeshore owners to report mudpuppy observations and die-offs
The Minnesota Department of Natural Resources is asking lakeshore owners and citizens to report any mudpuppy salamanders they see, especially die-offs on rivers and lakes. A die-off is defined as five or more dead salamanders in a lake at the same place at the same time.
"We have had several dead mudpuppy reports by lake residents these past few years on Big Cormorant and Melissa lakes in Becker County," said Krista Larson, DNR nongame research biologist. "We have collected salamanders to try to determine what has been killing them, but so far, the results have been inconclusive."
In 2013, mudpuppies were added to the Minnesota Endangered Species List and listed as Special Concern because of habitat loss, stream siltation and pollution, and overharvest for bait or biological supply companies.
Many people mistakenly call tiger salamanders "mudpuppies" or "waterdogs." In fact, mudpuppies are a separate species and the largest salamander in Minnesota. While tiger salamanders spend their early lives in water and adult lives on land, mudpuppies are Minnesota's only fully aquatic salamander, meaning they spend their entire lives in water.
Mudpuppies are about 13 to16 inches long, brown or grayish in color, have spots peppered along their back and sides, and a light gray or buff underside. They have small eyes, a paddle-like tail for swimming and external gills that look like feathery projections near their head.
Tiger salamanders are 7 to 13 inches long and are black with yellow markings. They are easy to separate from mudpuppies if they are adults (lacking external gills), but the young (larval) form resemble small mudpuppies.
Mudpuppies have four toes on their back feet and tiger salamanders have five toes. Additionally, mudpuppies have a back (dorsal) fin only on their tail, whereas larval tiger salamanders have a dorsal fin that goes from their tail and nearly reaches their head.
They are found in large to medium rivers throughout Minnesota, and also in lakes around the Alexandria and Detroit Lakes area. They can be found in swift gravel-bottom streams to slow muddy rivers. They lay eggs on the undersides of rocks, sunken logs or other underwater structure.
Most reports of mudpuppies are typically generated from anglers in the fall, winter, and spring when this species feeds heavily.
People who catch mudpuppies on hook and line will often kill them because of the erroneous belief that they are poisonous or venomous, or some anglers are simply unfamiliar with them.
Mudpuppies, though extremely slimy, are neither poisonous nor venomous, and the hook can safely be removed as with fish. If the hook has been swallowed, it may be best to cut the line as far back into the mouth as possible before release.
This species is relatively easy to detect in lakes using traps, but seemingly difficult to capture in its eastern river and stream habitats using similar techniques.Therefore, any specimens caught in the state should be photographed before release and reported to the Department of Natural Resources to gain better knowledge of mudpuppy distribution and abundance in Minnesota.
Research on mudpuppies and other nongame wildlife is funded by donations to the Nongame Wildlife Program and the Nongame Wildlife checkoff on Minnesota income tax forms.