Thursday, January 7, 2016

Oceanography

During my week at the Outer Banks of North Carolina, I learned about many different types of sea creatures, and found several of them along the coastline!!

I learned that horseshoe crab skeletons are mainly made of three pieces : the head, body, and tail.  We found all three of the main parts of a horseshoe crab, in three different places, and they all match up in size!  I also found out that creatures, like limpets and barnacles, can live on top of other creatures, such as horseshoe crabs and conchs. 


A conch is a type of sea snail, which spirals into a shape that slowly gets wider as it goes down into a triangle.  The conch’s shell wraps around it’s body, all the way to the tip, so that it can be firmly attached and protect itself against predators.  Some conchs will eat other conchs by sending a long tube up through the spiral into the back of the other shell where the conch snail is.  Most of the smaller conch eat plankton, but the larger ones are typically predator conchs.  Speaking of conch shells, we found four different types. 

Blue soft shell crabs are the only type of crab that you can eat with the shell still on.  Their shell is soft enough to eat, but even though it’s soft, it is still hard enough to protect and defend themselves while they are alive.  Nothing about the exoskeleton changes when they die, but the skeleton is _just_ hard enough to protect it against predators.  We found a soft-shell crab that had washed ashore with only one pincher.  I used a piece of driftwood to prove how strong its pinchers were…it broke the stick in two. 

Sea snails are similar to a conch, but they’re in a different side of the sea snail family.  They have a spiral shell, but instead of being in a triangular pattern, it’s in a flatter, circular pattern.  Unlike the conch, because their shell is not long enough to retract their whole body into the back, they have a piece of cartilage that will fold over the opening so that predators cannot enter or eat them.  We found two sea snails and five sea snail shell tops.
One of the coolest things we found was (what we think is) a large shark tooth!  Sharks are one of the biggest types of fish in the ocean.  Some sharks are as big as my hand, but some are as big as a school bus.  They can weigh over 3,500 pounds!  You’d be surprised to learn that most sharks don’t have very many bones.  Only their teeth are made of real bone…the rest are soft, thin cartilage which leaves extra room for muscles so that sharks can move very quickly through the water to catch their prey!  A shark’s body is perfectly designed for cutting through water, which is another reason that they are so fast.

I’ve learned a lot on this beach trip, and I really hope that I can come back again!!

No comments:

Post a Comment