I Speak for the Fish is a monthly column written by Great Lakes Now Contributor Kathy Johnson, coming out the third Monday of each month. Publishing the author’s views and assertions does not represent endorsement by Great Lakes Now or Detroit Public Television. Check out her previous columns.
At 10 pm we headed to the river for a night dive.
The shad were running and the massive school of fish had done an excellent job of keeping a safe distance from us all day. We hoped the cover of darkness would enable us to get some close-up shots.
My dive light offers the same illumination as a standard flashlight. It provides enough light to see where I am going but doesn’t penetrate the darkness beyond a few feet. In contrast, the lights for our underwater camera system are bright enough to land an airplane.
On night dives, when we turn the camera lights on, some of the fish go a little crazy.
The sudden illumination from our camera fractured the school of shad and sent them zipping and zooming in all directions. Their sterling silver bodies filled the darkness around us like aquatic fireworks.
Nocturnal predators are ready and waiting for such opportunities. And a big hungry mudpuppy took full advantage of the temporary chaos our lights caused.
In the swirling confusion of the shad school, we didn’t see the mudpuppy strike.
When the school reformed and our lights scanned the river bottom there he was. Impossible to miss with half a shimmering fish sticking out of his mouth.
A mudpuppy took advantage of the diver’s night lights to snag a gizzard shad. (Photo Credit: Greg Lashbrook/PolkaDot Perch)
The shad was a good 6 inches long, about half the length of the mudpuppy. The fish was so big that a portion of its body and its entire tail were still sticking out. The mudpuppy’s mouth was stretched to the max to accommodate the shad’s width.
With four dainty toes on each foot, mudpuppies are slow walkers. With the oversized meal hanging out of its mouth, the mudpuppy struggled to move forward. The fish’s tail kept flopping down on the river bottom, tripping him up.
He eventually made it back to his cave with his super-sized midnight snack. Turns out, if you’re a mudpuppy, while it might not be easy you can bite off more than you can chew.
A mudpuppy bites off more than it can chew. (Photo Credit: Greg Lashbrook/PolkaDot Perch)
Two schools
As often happens with aquatic species, when it comes to mudpuppies, there are two distinct schools. People like me — who think they are wonderfully cool. And the haters who think they are horribly weird.
I think people would like mudpuppies more if they could see them in their natural habitat.
Unlike other members of the salamander family that start their lives underwater but then crawl out and remain topside, mudpuppies spend their entire lives underwater.
A mudpuppy’s gills are external. Underwater the gills look like merlot colored pom-poms on each side of their head. Each fluffy pom swirls and billows as the mudpuppy rhythmically fans them. It’s delightfully captivating to behold.
Topside the gills collapse like a latex balloon when the air is released.
Mudpuppies are amphibians which means their skin is thin and vulnerable to whatever is in the water around them, which makes them a good indicator of water quality. To help protect their sensitive skin, mudpuppies secrete a mucus coating that shields them from irritants and, as a bonus, makes them glide more smoothly through the water.
Topside it feels slimy and… icky.
Author Kathy Johnson points out a mudpuppy sheltering under a rock. (Photo Credit: Greg Lashbrook/PolkaDot Perch)
Mudpuppy are sometimes called waterdogs because of river-lore that claims they make a barking sound when held out of the water or are otherwise in distress. Others say that’s all hogwash.
Hatchlings and juveniles are dark brown with a lemon-yellow stripe along each side. Adults are usually light brown or grey with a sprinkling of dark spots and a creamy belly. A dark line running through their eyes does an excellent job of camouflaging their gaze.
They have a flat paddle-like tail reminiscent of a beaver. And, like beavers, mudpuppies can use their tails to achieve remarkably fast speeds. I didn’t expect an aquatic salamander to be a particularly fast swimmer until I saw one zoom upstream in a six-knot current. It left me in its wake.
Mudpuppies are the largest of the salamanders in the Great Lakes. Adults reach lengths of 13 inches or more. They can live for over 20 years but don’t reach sexual maturity until they are 10 years old.
Strange Bedfellows
When the leaves have changed color and begin blanketing the ground in autumnal shades of yellow and red, the mudpuppies mate. But the females will not lay their eggs until the snow and ice of winter have melted and spring flowers start to peak up in the garden.
Each female will deposit 50-100 eggs in a nest tucked under a rock,log or pile of debris. Each tear-drop-shaped egg sack hangs from the ceiling of the nest like a boxer’s punching bag. The female will guard the nest for the entire 1-2 months it takes for the eggs to hatch.
Mudpuppy eggs hang from the ceiling of a nest. (Photo Credit: Greg Lashbrook/PolkaDot Perch)
The female will continue to protect her young for several more weeks until they are strong enough to face the river and all its predators alone.
When it comes to reproduction, mudpuppies play an important role for another species. Salamander mussels can’t survive without the help of mudpuppies.
After spawning and incubating her young, the female salamander mussel must transfer her larvae to the mudpuppy’s gills to complete their development.
The larvae mussels do not harm the mudpuppies. They simply catch a free highly-oxygenated ride for about three weeks. Tune in to this month’s Great Lakes Now segment to learn more about efforts to save native mussels — airing Monday, January 27 on all PBS platforms.
Bad Rap
Mudpuppies have been accused of being poisonous and eating enough fish eggs to depress sportfish populations. But, according to Michigan Sea Grant, they are not poisonous and there is no evidence that mudpuppies impact native fish populations either through egg consumption or competition.
They eat crayfish, insect larvae, snails and small fish including the invasive round goby.
In 2016, the mudpuppy was elevated to a species of concern in Michigan. Mudpuppies are also a species of special concern in Indiana, Minnesota and Pennsylvania. They are considered a threatened species in Illinois and a species with “greatest information needs” in Wisconsin.
Mudpuppy are not protected in Ohio waters and are considered “not at risk” in Ontario, although their numbers have declined across most of its historical range.
Although mudpuppies are not considered to be at risk in Canada, a few are benefitting from their association with the salamander mussel which is federally listed as endangered.
The Sydenham River in Southwestern Ontario contains one of the few salamander mussel populations remaining in Canada. At the one locality on the river where the salamander mussels are found, the mudpuppies are also protected.
Threats to mudpuppy populations include loss of habitat from dredging, damming, and pollution. Some chemicals, particularly TFM used to kill lamprey are fatal to mudpuppies.
In 2022, the Wisconsin DNR, with support from field biologists and the public, began the first statewide assessment of mudpuppies. They conducted more than 75 surveys in 19 counties. By 2023, they confirmed mudpuppies were present in nearly every county in Wisconsin.
If you catch a mudpuppy, gently remove the hook, snap a quick photo (don’t make it a photoshoot!), then put the puppy back in the water. In Wisconsin, you can report the sighting and upload the image using the Wisconsin DNR online form.
Mudpuppy encounters can also be reported online to the Michigan Herp Atlas. The Michigan Herp Atlas Project is a citizen science program that collects observation data about Michigan’s amphibians and reptiles.
There’s even a Mudpuppy Facebook page if I’ve converted you to the wonderfully cool school.
Catch more news at Great Lakes Now:
I Speak for the Fish: How Native Americans are saving lake sturgeon
I Speak for the Fish: Where’s the line in fisheries research?
Featured image: Mudpuppies are aquatic salamanders with fluffy external gills. (Photo Credit: Greg Lashbrook/PolkaDot Perch)
