Remember the last time you stood at the edge of the ocean?  Perhaps you climbed some rocky ledges and gazed into tidal pools or maybe you were standing on a pier.  If you looked closely you may have seen barnacles or mussels stuck to whatever surfaces were available.  Despite the ever-crashing waves, they were stuck, like glue.

Recently, a team from McGill University described how mussels achieve this adhesion.  

Photo 159976138 / Mytilus Edulis © Milton Cogheil |

The blue mussel (Mytilus edulis) uses an internally produced fluid protein and mixes it with iron and vanadium extracted from seawater.  Within 2 to 3 minutes, the glue is useable by some of the mussel’s anatomical parts. 

As you may know, mussels have beards.  (If you ever cook mussels, you remove this part before cooking, or at least you should.  It’s rather chewy otherwise.)  These are made up of 50 to 100 fibrous byssal threads that keep the mussels tethered in place. At the end of each thread is a disc-shaped plaque that becomes the interface for applying the glue to the target surface. 

This glue is strong enough to withstand the corrosive effects of saltwater.  Consequently, understanding its composition and properties may lead to new products for applications such as surgical sutures.  After all, the body is 70% water and rather salty.  

Barnacles, on the other hand, may create a somewhat different type of glue.  Their biochemistry was described in detail in 2019.  Barnacles may have up to three different events in their lifecycle that contribute to their adhesive chemistry.  It is so complex that I don’t feel qualified to summarize it here.   A comprehensive overview is available at:

Once again, nature offers more than one solution to the same sticky problem. 

Unfortunately, the mussel glue academic paper is behind a paywall, but here is McGill’s press release:

There is also a video of the mussels making the glue here:

I may be the last person to learn these things, but just in case I’m not, I thought I would share them with you.

  • Did you know that some jellyfish species are found in freshwater?  I always thought that they were strictly saltwater creatures.  These freshwater types are known as medusas (Craspedacusta sowerbyi).  They seem to appear sporadically in blooms so they aren’t always there to observe.  

Some scientists speculate that they are airlifted from their point of origin which is believe to be the Yantzee River and “deposited” by birds in lakes and streams.  However, no one has ever seen a jellyfish attached to a duck, for example.  You may think that this is a geographically isolated phenomenon but these jellyfish have been found in locations as distant as Australia, Chile, and in my home state of Maine. 

Medusa Freshwater Jelly
Image by Rostislav Stefanek at
  • Because I never thought about it, I assumed that humans were the longest living mammals on the planet.  That is incorrect.  Bowhead whales (Balaena mysticetus) live to an average age of 200 years if we don’t kill them first.  That’s still a brief lifespan compared to the Greenland shark (Somniosus microcephalus) which lives for 300 to 500 years.  This is the longest living vertebrate animal, beating out the Galapagos Giant Tortoise (Chelonoidis niger complex) and Orange Roughy (Hoplostethus atlanticus), both of which live for up to 250 years.

    Greenland Shark
    Image by Planetfelicity at
  • And while we are exploring some aquatic novelties, there is an 18-foot shark called the Megamouth Shark (Megachasma pelagios) that has been spotted only about 100 times, ever.  Despite its enormous mouth, this shark has tiny teeth.  It is a filter-feeder, eating only plankton and jellyfish.  

Consequently, stories that the shark was discovered when it swallowed a US Navy ship anchor in 1976, may be an exaggeration.  More likely, the shark became entangled in the anchor’s cabling. 

Another unique feature of this deepwater shark is its silvery-white upper lip. At one time, scientists wondered if it was bioluminescent in order to lure its prey.  Research conducted in 2020 uncovered that it was merely highly reflective.  This is an interesting adaptation, nonetheless.


More about freshwater jellyfish —

More about freshwater jellyfish in Maine —

More about the age of various animals —

For more information about the Megamouth — watch NatGeo’s World’s Weirdest, Season 5 Episode 3

Study about the bioluminescence study of megamouth —

Can you imagine a species so beautiful that, despite laws prohibiting removal, people can’t seem to resist taking them home?

The Painted Snail species (Polymita) is endemic to Cuba.  Unfortunately, extinction is a real possibility.   Their attractive shells are desirable for jewelry, art, and collections.

Painted Snail Shells
Image by Pnsj88 at

Dr. Bernardo Reyes-Tur, a professor of conservation biology at University Oriente in Cuba, and his students are trying to study these beauties and make a positive impact on the species’ future.  In 1995, Dr. Reyes-Tur began a snail breeding laboratory.  However, he faced a difficult challenge finding a sufficient and affordable source of appropriate containers for the effort.   

His students offered an ingenious solution.  They recognized that the liter water bottles most frequently used and discarded by the island’s tourists would make a perfect environment for breeding and management.

The breeding program and the research appear to be thriving.  If only the same could be said of the species.   If you see these incredible shells on sale, please don’t buy them.  Let’s do our part to ensure that future generations can stumble upon one of these gems when wandering through a Cuban mangrove. 


More info and a great picture of the breeding lab —

Surely there are some things that I know for certain, aren’t there?  Maybe not!  Here are a few “facts” that have not stood up to the test of time.

  • Trees grow in the daytime when they can use the sun to photosynthesize carbohydrates from carbon dioxide, right?

    Majestic Tree
    Image by RegalShave from Pixabay

Not according to the latest research from the Swiss Federal Institute for Forest.  Their studies show that trees actually do most growing at night.  They monitored seven common species for up to eight years.  Simply stated, what they learned was that air humidity was the key to tree growth.  During the day, when the air becomes drier, trees temporarily lose more water through transpiration than they absorb through their roots.  As a result, growth stops, regardless of photosynthesis.  

(As a reminder: The same amount of water vapor results in higher humidity in cooler air than warm air.)

  • If an animal is decapitated, it’s dead, right?

Not if we are talking about the sea slug (Elysia marginata).  Separate the head from the body and both sections can continue to live independently of the other for several weeks to a few months.  Eventually, the headless body will start to decay.  However, the head will regrow a new body, heart, and other organs.  

These Elysia marginatas are not the only organisms that can perform this magic.  At least one other slug species can do something similar. 

  • The Chesapeake Bay was formed when glaciers carved the channels and troughs a the end of the last Ice Age, right?
Chesapeake Bay
Image by mcfisher from Pixabay

That’s only part of the story.  Around 35 million years ago, a bolide (a very bright meteor) exploded near where the Bay sits today, creating a deep canyon.  The subsequent tsunami continued to redefine the area. The displaced water reached all the way to the Blue Ridge Mountains.  

The impact’s effect was only confirmed in 1993.   Oddly, it was missed when the Chesapeake Bay Tunnel was built because the excavation didn’t go deep enough to reveal the evidence.

Thanks to @DrAndrewThaler for the tweet that clued me in to this information.  

I can’t wait to find out what new information will dispel the next set of facts!


More about tree growth at night —

More about beheaded slugs —

 For more information about Chesapeake Bay formation —