6 minute read
Mudpuppies And Salamander Mussels: Clean Water Dream Team
Katharine Caywood
Katharine Caywood is a communications and marketing specialist for the DNR’s Natural Heritage Conservation program.
A guiding principle in conservation is that we can’t protect what we don’t understand. When it comes to mudpuppies and salamander mussels, two notoriously overlooked native species that are important indicators of a healthy waterway, we’re taking steps to learn more.
With support from the Natural Resources Foundation of Wisconsin, the DNR conducted the first statewide survey for mudpuppies, a species of salamander, and used that data to find salamander mussels. The latter depend on mudpuppies to complete their life cycle and are a threatened species in Wisconsin.
Mudpuppies, also known as “waterdogs,” can grow up to a foot long, making them Wisconsin’s largest amphibian. Their stubby digits and long paddle-like tail give them the appearance of a creature caught between life on land or in water.
Most salamanders only begin their lives underwater, hatching from eggs laid in shallow pools. External gills shrink inward, they metamorphose into their adult form and move from swimming and breathing underwater to living largely on land in forested, damp habitat.
Mudpuppies don’t go through full metamorphosis, and they retain their signature fluffy, red external gills that bloom from either side of their head, allowing them to spend their entire lives underwater.
Information Is Key
The mudpuppy (Necturus maculosus) is considered a “species of greatest information need,” which means there are indications its population is at risk of decline, but more data is needed. However, their habitat and behavior make it difficult to know for sure.
Unlike many other amphibians, mudpuppies avoid warm, shallow water and are more likely to be seen in the fall and winter than in spring or summer.
In 2022, the DNR and dedicated contractors — with support from the Natural Resources Foundation’s Wisconsin Amphibian and Reptile Conservation Fund — were finally able to gain a better understanding of the mudpuppy’s status statewide.
“In the past, our fisheries managers would report on bycatch, grad students have done research and surveys, but there has never been a statewide effort to study mudpuppies,” said Rich Staffen, DNR terrestrial zoologist. “We couldn’t have done this without funding from NRF.”
New Methods, New Data
DNR staff and contractors conducted over 75 surveys in 19 counties between September 2022 and July 2023. The high volume of surveys provided a unique opportunity to refine methods for finding these elusive creatures, noted Rori Paloski, DNR herpetologist.
“Typically, mudpuppy surveys are done with waders or snorkeling and flipping over rocks until a mudpuppy is found,” Paloski said. “Some researchers have also found that baiting them, especially with cheese, can be very effective.
“However, our contractors found that shining at night in shallow water was most effective in finding mudpuppies and allowed us to catch them to gather accurate size and gender data.”
Additionally, they worked with fisheries biologists on reporting and asked the public to submit sightings. By July 2023, populations of mudpuppies were confirmed in nearly every county in Wisconsin, including four counties where they hadn’t previously been recorded.
Mudpuppy As Host
The new data on mudpuppies has had a ripple effect on the outlook of salamander mussels in the state. In 2023, the salamander mussel (Simpsonaias ambigua) was proposed for federal listing as an endangered species.
Wisconsin has 50 species of native mussels, and 50% are threatened, endangered or of special concern. Salamander mussels prefer the same habitat as mudpuppies: crevices under and between rocks that provide respite from currents and some protection from predators.
Their shared habitat is no coincidence. Salamander mussels, as their name suggests, have a crucial connection to salamanders — in this case, mudpuppies.
All mussels are “obligate parasites,” which means they rely on another species to reproduce. Most native mussels use fish, but the only mussel in the world known to have a nonfish host is the salamander mussel. Their host? The mudpuppy.
Freshwater mussels use a variety of adaptations to attract fish so their glochidia (larvae) can harmlessly attach to the gills, where they’ll mature and transform into tiny mussels, then drop off to begin life in their adult form. Though salamander mussels don't occur everywhere mudpuppies are found, with improved mudpuppy distribution data, we can more easily locate salamander mussels and identify opportunities to regenerate the salamander mussel population.
Mark Of Clean Water
What makes this so important? Mudpuppies, like all amphibians, and mussels are vital indicators of environmental health.
Amphibians’ thin, permeable skin means they absorb whatever is in the water or moisture around them through their skin. That’s a problem when it contains pollution and pesticides or during drought conditions.
If you see a toad in your garden, encounter a salamander in the dirt or have waterfront property where frogs, turtles and maybe even mudpuppies make their home, those animals are a sign of healthy land and clean water. Avoiding pesticide use can help keep it that way.
Mussels filter water, clearing it of contaminants that harm human health, like algae and even bacteria. A single mussel can filter up to 15 gallons of water per day, significantly improving water quality in rivers and lakes.
When there are abundant populations of a wide range of native species, including amphibians and mussels, our ecosystems are more balanced for nature and us.
Funding Is Key
The Wisconsin Amphibian and Reptile Conservation Fund, started by the Natural Resources Foundation in 2017, provides dedicated funding for specific species. With 55 reptile and amphibian species in Wisconsin and nearly 50% categorized as special concern, threatened or endangered, prioritizing projects among those in need is an ongoing challenge. For more on the fund or to make a gift, visit The Wisconsin Amphibian and Reptile Conservation Fund website.
Make Note Of Mudpuppies
If you’re on the ice this winter, report mudpuppy sightings. Colder temperatures allow them to look for food nearer to the surface, so they’re sometimes seen or caught by people who are ice fishing.
If you catch one, snap a photo, gently remove the hook and return the mudpuppy to the water. Then, report your observation to the DNR using our online form.
