MUCUS and other wonders of the physical world

Zoobots aboard the Centennial at Friday Harbor Labs. We were trawling for spot prawns on the first real sunny day of spring. Perfect.

Re-inspired by a recent encounter with a stranded banana slug, I think it is finally time to bring to life a blog that I started in January. It’s time to tell the story of the advent of Mary Krauszer’s love of and practical advice about mucus.

The beginning:

Some time last fall, ailed by a particularly potent bout of the common cold, and inspired by the variability of the gelatinous excretions of my persistent congestion, I think I literally had mucus on the brain – or is that meningitis?

Then these glorious glycoproteins started showing up in all my classes. Respiration in my Comparative Animal Physiology class required a medium across which to diffuse gas, making mucus imperative to most oxygen-consuming life.

The motile marine invertebrates in the first-year biology class I TA-ed needed a way to traverse the wet and varied ocean floor, smearing mucus everywhere they went to enable locomotion.

The miraculous lungfish discussed in Vertebrate Biology survived the droughts of Africa and South America by secreting a  mucus cocoon and remaining underground for years until adequate rainfall returned (

Mucus makes the world go around.

And thus, I discovered my new life goal: I will be a PhD of Mucunology. Ok, so that probably isn’t a word, but I need to convey the profundity of this epiphany. The wonders of mucus are endless and I could spend my whole career exploring them.

Banana slugs!

Things I have discovered about mucus thus far:

1. Banana slug mucus DOES NOT WASH OFF. Seriously. Hot water and soap has nothing on that stuff. Someone better be figuring out what it is made of, because that is an impressive substance and I bet we could solve some world problems with it. And now you’re asking, “what were you doing with slug mucus on your fingers, Mary?” Saving its life, duh.

2. Mucus is easy to make, keeps you healthy and safe, and can be used as a measure of character.

There are a plethora of marine animals that use mucus as a defense, sometimes just oozing it out by the bucket-load because it really isn’t that expensive. Metabolically expensive, that is. In fact, animals such as hagfish and slime stars use mucus to save themselves from the grips of predators, by literally making themselves hard to hold on to ( and These animals secrete a pretty cheap protein that is hydrated by the water around them and forms a thick, translucent slime.

In an outreach project at the elementary school here at Friday Harbor, I demonstrated a slime star to sixth graders. It was a morning of crowd control, as the students wanted little else from my Echinoderm table than to cover themselves and each other with slime. Sadly, the terrified slime star had transformed basically all of the water in its container to slime long before the demonstration was over and we had to dial back the enthusiasm. But speaking of enthusiasm, a student’s willingness to experience the mucus of the slime star was directly related to their willingness to participate in the educational portion of my presentation. Those students who squirmed and squealed also didn’t pay attention and probably couldn’t tell you the distinguishing features of their Asteroidea class.

3. However, somewhat to the contrary, it is not a socially-appealing fact to share that you “like mucus”. Yeah, I did that in one of those “tell us your name and something interesting about yourself” sessions at the beginning of my study abroad program. Apparently it took me a while to recover from that one, but then I showed them the slug sex video and started over at square one.

Larvacean, the wormy thing with a big head. Actually a solitary tunicate.

4. Mucus is good for eating. Well, mucus is good for catching stuff that you can then eat. The larvacean is a free-swimming tunicate that basically looks like the baby alien in the movie Alien, with a creepy head and an alarmingly twitchy, wormy back-end. This weird zooplankter spends its life floating around and secreting an elaborate mucus filter larger than its own body and catching other plankters for eating. This method is very efficient and these aquatic aliens do quite well, especially around spring blooms like the one pictured here in the plankton tow I collected on Tuesday.

5.There is no verb for the action of producing mucus. I’m going to make one up when I’m a famous biologist.

6. You ‘mucate’ (copyright Mary Krauszer) when you are sick, not because that is what a cold does to you, but because your body’s immune system needs to clear out all the junk it’s been making and/or killing, so it doesn’t just sit around in your system. What better plunging apparatus than a gelatinous goo that both flows and holds garbage quite nicely?

Sorry if you’ve heard this all from me before. Perhaps, I really am a one-trick pony. One slimy trick.

This entry was posted in Mary Krauszer '12 and tagged . Bookmark the permalink.