Mudpuppies! No, we are not talking about dogs

While not as cuddly or playful as a fuzzy puppy, mudpuppies play an important role in our ecosystem and should be handled with care.

For decorative purposes.
Mudpuppies have slimy, splotchy brown-gray skin that enables them to camouflage among leaves and rocks in the water. Another unique adaptation is their external gills which aid them in breathing. Credit: Matt Keevil

You might not guess it from the name, but mudpuppies (Necturus maculosus) are actually a species of freshwater dwelling salamander. Salamanders are a type of amphibian and unlike their noisy frog cousins, they typically make very few vocalizations. However, the mudpuppy, also called the ‘waterdog,’ was named because of their squeaking or squealing noise that some thought sounded like a dog's bark. Mudpuppies are one of the largest species of salamanders in Michigan and can grow to be over a foot long. Most individuals range from 8 to 13 inches. They are one of 12 salamander species found in Michigan.

Besides being large and sometimes making sound, mudpuppies are unique in that they never leave the water. Typically, most species of amphibians go through metamorphosis from a water-dwelling juvenile stage to an adult that lives on land. Instead, the mudpuppy keeps its larval characteristics, such as its prominent and bushy external gills, making them easy to identify. Like all amphibians, mudpuppies have slimy and sensitive, permeable skin. These nighttime carnivores eat any water-dwelling invertebrates (e.g., crayfish, worms, snails) and even some vertebrates like tadpoles and small fish. They aren’t picky in their diet and will eat whatever they can catch that fits in their mouth.

Mudpuppies are native to central North America and can be found in rivers, ponds, inland lakes, and along shallow areas of the Great Lakes. They are active year-round and do not hibernate. They spend most of their time hiding near rocks, under logs, and among plants and are rarely seen during the day. In summer and winter they live in deeper water and they move to shallower water in the spring and autumn.

Mudpuppies are often misunderstood and because they are rarely seen, it can be quite a shock to find one attached to a fishing line or spotted in shallow water. They are sometimes discarded or even killed because they are mistakenly thought to be poisonous, although they are not. They are also threatened by needless persecution, as some anglers kill mudpuppies in the mistaken belief that they reduce populations of game fish. However, there is no evidence they negatively impact fish populations.

Mudpuppies serve a vital role in the ecosystem and are a source of food for aquatic predators like large fish, herons, and water snakes. Unfortunately, due to habitat loss, reduced water quality, and sensitivity to lampricides, the Michigan Department of Natural Resources elevated mudpuppies to a Species of Concern in 2016. Because of their sensitive skin, they are especially vulnerable to toxins in the water. Thus, their presence may be an indicator of a healthy ecosystem.

Although still common in some parts of the state, mudpuppy populations are declining overall. If you are lucky enough to find one, it should not be collected or removed from the wild. Instead, you can help scientists by reporting any sightings of mudpuppies through online databases like iNaturalist. Keep in mind mudpuppies are active throughout the year and are more likely to be caught during ice fishing season. Anglers who catch a mudpuppy on a fishing line should gently remove the hook and return it to the water.

Interested in learning more about the wonders of lakes and how best to protect them for future generations? Participate in the Michigan State University Extension Introduction to Lakes Online course. From the comfort of your home learn about lake ecology, aquatic plants, shorelines, watersheds, and much more. The course is offered yearly and the 2023 course kicks off January 10.

A version of this article originally published in the November/December 2022 issue of the Lakefront Lifestyles magazine.

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