Something Slimy & Spectacular

Grinning from ear to ear, our group of three hovered over the small workspace as I pulled a slimy, slight stinky specimen from a Ziplock bag. The common mudpuppy - after having died, washed up on shore, been frozen, and just recently thawed - had a gelatinous skin of dark gray with mottled blue all over their body. They could have been an alien (or, as a viewer of the wildly popular Stranger Things series, I immediately compared the strange mudpuppy to a creature that would be right at home in "The Upside Down"). Excited to examine them more closely, we placed the body on our work table and got started.

Cade Campbell found this common mudpuppy (Necturus maculosus) washed up on 
the shore of Lake Namakagon. Interns Cade and Olivia brought the mudpuppy
to the Museum for preparation and admission as a specimen.

As naturalists, we were right at home handling the dead salamander. A normal day in the field would naturally involve a bit of "ick" - whether that's carefully transporting a spider off a participant's shoulder or kneeling down to get an intimate look at some trailside scat. So, we used our fingers to prod around the body in case there were any physical clues left behind about the mudpuppy's life. 

The first feature we investigated was the mouth. Cade worked to pry the jaw open, but it was a struggle. Salamanders generally do not eat using a crushing force. Rather, their mouth opens wide enough to capture small prey like worms and insects, and their tiny teeth help to hold the prey in their mouth as they work to suck it back into the throat. 

I've fed Scuba, the terrestrial western tiger salamander in our live collection, countless times and have never noticed the rows of tiny teeth in his mouth as he hastily grabbed at a mealworm. This mudpuppy, however, had a row of teeth that we could readily see once we pulled back their lips. Something brown and soft (mud, or perhaps uneaten food?) was almost within reach behind their teeth, but the tiny little bars kept us away. 

With lips pulled back into an unnatural grin, a row of tiny teeth are exposed.

Once we had explored the mouth as thoroughly as possible, Olivia stepped in and used the tip of her finger to gently prop up the mudpuppy's characteristic gills. Mudpuppies are pretty spectacular in that they retain their plume-like external gills into adulthood - a feature which is otherwise lost in salamanders after the larval stage. These gills help a mudpuppy to gather oxygen from underwater, as this is where they spend all of their time. They're actually an organ made of branching blood vessels, much like lungs, and both serve the same function. 

A mudpuppy's external gills tend to appear feathery and crimson-red in life.
Photo by Cullen Hanks, some rights reserved.

Now extracted from their freshwater home, this mudpuppy's body will be maintained in a new liquid environment. Like many of the macroinvertebrates, frogs, and even mushrooms preserved at the Museum, the mudpuppy will become part of our wet specimen (or alcohol-preserved) collection. They're currently sitting in a bath of ethanol, where every day one of us naturalists will agitate the liquid to aid in the preservation process. 

The body of this mudpuppy has already started to become rigid as 
it sits in a bath of ethanol. This fluid will be changed out in about two weeks
once liquid exchange slows.