Portfolio: Havergal College Student Treehouse Portfolio


Mercenaria's Underwater Adventure


Once upon a time, deep in a less-salty bay, there lived a little clam by the name of Mercenaria mercenaria.  Mercenaria and his family lived burrowed in the shallow, soft, muddy bottom of the bay.  Mercenaria’s family was very fond of their home because they were protected from the wave action.  A long time ago, before Mercenaria was born, his mother and father used their muscular feet to dig themselves into the ground.  Since then they have grown old and live quiet, immobile lives.  Mercenaria and his mother and father spend most of their time having scintillating conversations on every imaginable topic and eating constantly.  Since clams eat by taking in water and separating it from the tasty plankton and algae, they clean the water for the benefit of other animals.

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Click on an image to view larger version & data in a new window

Mercenaria mercenaria. © mollusk2 

Clams have shells to protect their soft bodies, so Mercenaria and his family don’t have to worry about predators, as long as they don’t stray from their safe home.    

One day Mercenaria was looking up at the light shining through the water, wondering what amazing things were happening outside his sandy home.

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Click on an image to view larger version & data in a new window

Mercenaria mercenaria. © mollusk2 

Lately, Mercenaria had been feeling very restless and wanted to get out of his boring home to explore the bay around him.  His father had told him to never venture out of their safe haven because if he did, predators like birds, large fish and sea otters might eat him.  There was also the threat of humans.  Since Mercenaria didn’t have the ability to move, there was not much chance of him leaving his house.  Just last year, Mercenaria’s uncle, who was very old at the age of forty, was captured in a net and was never seen again.  Mercenaria was very afraid of that fate, but he still daydreamed constantly about the wonders of the underwater kingdom that he would most likely never see.  Unless…Mercenaria decided to use his muscular foot to drag himself around and explore the bay bottom.  He could only move slowly, so he would have to leave very early and  would probably have to spend the night away from home while on his adventure.  Mercenaria decided that at dawn the next day, he would set out to explore the world, all alone.  He hoped that his parents would understand that he needed to satisfy his curiosity about the world.  The plan was settled and Mercenaria hurried to get ready for bed.  The sooner he did, the sooner his adventure could begin.

The next day Mercenaria woke up early.  He quickly snacked on some algae and prepared himself for the journey.  He quietly pushed himself past his snoring parents.

Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window

© mollusk2

Once outside, Mercenaria felt a thrilling rush of excitement go over him.  He was finally going to see the world outside his home!  He set off quickly at first, using his muscular foot with much enthusiasm.  He passed brightly colored schools of little red fish and gazed at them in amazement as he moved along through the sand. 


Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window

© mollusk2

At first, everything was so fascinating.  Mercenaria saw the glittering scales of clown fish flash by him and friendly turtles wink their huge eyes in the bright sun.  However, Mercenaria gradually began to realize that things were getting unfamiliar and scary.  Soon he looked around and saw no happy sea horses bobbing along or other young clams looking up at him, envious that they could not go out and explore as well.  Mercenaria only saw the sharp, jagged claws of crabs and shadows of sea otters from overhead.  Maybe this was the place Mercenaria’s father told him never to go to.  Just as Mercenaria decided that he would turn around and retrace his steps back home, a huge net came down and scooped him up.

Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window

© mollusk2

He was trapped inside a net with millions of other clams just like him.

“Let us out!” One very large clam yelled.

“You’re squishing me!  Get off!” Two brother clams shouted at each other. 

Mercenaria was very scared.  How would he ever get out of here?  Would he end up having the same fate as his uncle?  And most importantly, why hadn’t he listened to his father?!  Mercenaria looked around frantically, trying to find an exit out of the giant net.  All of a sudden, the net began rising up through the shallow water.  

 “Oh no,” Mercenaria thought.  He felt a slight jolt and was given a bit more space as the clam that had been wedged in beside him managed to wiggle himself out of a hole in the net.  Mercenaria looked up.  The surface was approaching fast.  He didn’t have much time.  Using the ridges on his shell, Mercenaria began trying to weaken the rope of the net by rubbing it across his shell.  Other clams around him saw what he was doing and joined in.  All of the littleneck clams worked so hard that the entire net broke open and they were all set free.

Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window

© mollusk2

Mercenaria heard words of encouragement from his fellow clams that had seen him start trying to break the ropes first.  

“Good Job, Little Clam!  But, say, why are you out here all alone?  Were your Mommy and Daddy caught in that net as well?” An older clam asked Mercenaria.

“No, I was out on an adventure.  I have to be home right away.  I hope I will get there before dinner!” Mercenaria worried. “And I forget where to go!”

“No problem, little friend.  My name is George.  You can come with me!  I will help you get home.”  And so, with the aid of the older, very friendly clam named George, Mercenaria ended his adventure and found his way back to his safe house.   He could not wait to tell his parents about all the amazing things he had experienced.  Hopefully, they would forgive him for disobeying their words.

 “Mercenaria!  Mercenaria!”

Suddenly, Mercenaria opened his eyes.

 “Mercenaria it’s time for breakfast!” his mother was calling across the room to him.  Mercenaria realized he was at his house.

 “Mom, aren’t you angry at me?” Mercenaria asked tentatively.  He couldn’t believe that she wasn’t saying anything about him leaving home yesterday!

 “Why would I be angry with you, Mercenaria?  You haven’t done anything wrong!”  Mercenaria puzzled this for a moment.  Maybe his entire adventure was a dream.

“I don’t know, Mom.  I guess that was a silly question.  I’ll come over and eat now.” Mercenaria’s mother smiled.  Yes, it had all been a fabulous dream, that Mercenaria would never forget.

Meanwhile, an empty, ripped net was being hoisted on to a boat far above Mercenaria’s home.

“Oh my gosh!  There are no clams in this net!  What are we going to tell the boss?”

Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window

© mollusk2

Information on the Internet

  • Mollusks and other weird animals!  This website is useful because it talks about mollusks in general and the different classes of mollusks including bivalves which is the class that littleneck clams are classified in. It also has really nice images of different underwater animals.
  • Hard Clams  This website is useful because it has a lot of specific information about the littleneck clam/hard clam. It includes details about the lifecycle of the clam and how they reproduce in specific environments.
  • Pacific Littleneck Clam  This website has extended information specifically about the Pacific Littleneck Clam. It includes details about clam’s lifecycle, habitat, ecology and the scientific name.
  • Animal Diversity Web  This website is very useful because it not only has interesting information about mollusks but about the entire kingdom Animalia and the organisms in it. It has specific details about the clam such as how the clam opens and closes its shell. It also has some nice images.
  • Mercenaria mercenaria  This website has the taxonomy of clams, the life cycle, habitat, distribution, physical tolerances and lots of specific information about the clam.


1.) Class Bivalvia. [Online] Available http://animaldiversity.ummz.umich.edu/site/accounts/information/Bivalvia.html, October 7, 2005

2.) Hard Clam. [Online] Available http://www.chesapeakebay.net/info/hard_clam.cfm, October 10, 2005

3.) Campbell, Neil A. and Reece, Jane B. 2005. Biology: 7th Edition. San Francisco, USA: Pearson Education Inc. Pp 639, 652

4.) Midis. [Online Media] Available http://hhmeinen.de/midis.htm, October 20, 2005

5.) McHenry, Robert. Encyclopedia Britanica Vol. 3 Fifteenth Edition. Chicago: Encyclopedia Britannica, Inc.,1992.

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About This Page

Author: mollusk2
Classroom Project: Mollusk
Havergal College
Toronto, Ontario Canada

License: Tree of Life & Partners uses only - Version 1.0

Correspondence regarding this page should be directed to , Havergal College

 Treehouses are authored by students, teachers, science enthusiasts, or professional scientists. Anyone can sign up as a treehouse contributor and share their knowledge and enthusiasm about organisms. Treehouse contributions are checked for general accuracy and quality by teachers and ToL editors, but they are not usually reviewed by expert scientists. If you spot an error, please get in touch with the author or the teacher. For more information about quality control of Tree of Life content, see Status of Tree of Life Pages.

About This Portfolio
The ToL really appreciates the efforts of these teachers and students. Havergal College has produced some of the first treehouses created by students and we think they did a terrific job. Special thanks to Seonaid Davis, the coordinator of this project at her school, for becoming one of the first teachers to use the ToL's treehouse publishing system, and for inviting other teachers at her school to do so also. Nice work!

Lisa Schwartz
University of Arizona

Havergal College

Sarah Ianni
Havergal College

Kate Rowlandson
Havergal College

Correspondence regarding this page should be directed to Lisa Schwartz at , Seonaid Davis at , Sarah Ianni at , and Kate Rowlandson at

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