Ever Wonder What Lurks On the Ocean Floor?
By Howard J. Bennett
Aside from sunburn, the biggest concern most beachgoers have is getting sand on their pizza or being stung by a jellyfish bobbing around in the water. But there are thousands of creatures in the ocean, including some pretty gross ones. My three favorites are the hagfish, sea cucumbers and starfish.
The hagfish is one of the most disgusting inhabitants in the world. The reason the hagfish gets this dubious honor is because it is so gross in so many ways. Consider the following:
• It has an ugly eel-like body with a jawless, tube-shaped mouth that is surrounded by tentacles.
• It is both a scavenger and a predator, but has a ghastly way of eating. A hagfish enters its prey through the animal’s mouth, gills or anus and eats its way out!
• Because the hagfish has a preference for bottom feeding, its primary food source is dead animals. This can make it look like a dead fish is moving as the hagfish eats its insides.
• It produces a tremendous amount of thick slime when threatened or startled. The hagfish is able to do this because its skin excretes mucus and filaments that absorb large amounts of seawater. Once released, this material morphs into huge globs of thick, gelatinous goo. Check out the following link if you’d like to see hagfish slime in the making: HYPERLINK “http://www.metacafe.com/watch/1597296/hagfish_and_the_disgusting_slime/” http://www.metacafe.com/watch/1597296/hagfish_and_the_disgusting_slime/
Because sea cucumbers don’t have lungs, they do not breathe in the traditional sense of the word. However, like most sea creatures, they still get their oxygen from water and the water they “breathe” enters their bodies through their anus. The reason this occurs is because the animal’s gills are located just inside its rear end.
Seawater isn’t the only thing that enters a sea cucumber’s bottom. A handful of fish, most commonly pearl fish, have evolved an interesting relationship with sea cucumbers. Young pearl fish swim into a sea cucumber’s anus and use it for three reasons: (1) protection from predators, (2) a source of nutrients, and (3) a place to hangout until they enter their adult stage of life. Since the pearl fish neither harms nor helps the sea cucumber, this is referred to in biology as a commensal relationship.
The balance between predator and prey is often bizarre. Most starfish live on shelled animals like clams. (The clam’s defensive weapon is its shell.) When it’s feeding time, a starfish surrounds its prey with its strong arms. Then, it uses its arms to pry a tiny opening where the animal’s shells come together. The starfish then pushes its stomach out through its mouth and inserts it inside the clamshell. Now defenseless, the clam can do nothing but lie there while the starfish eats it. Once dinner is over, the starfish withdraws its stomach, “zips up,” and goes on its way.
It’s too bad kids aren’t built like starfish. That way, you could plop your stomach onto your dinner plate and “eat” your fruits and vegetables without having to taste them!
© 2012 Howard J. Bennett. All Rights Reserved.
(First published in the Washington Post 6/9/09.)
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please visit Dr. B’s website at www.howardjbennett.com.