Marine Life of the Osa Peninsula

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 Ian's Reports from Costa Rica
See some more of the flora and fauna of the Osa! Click on the orchid!
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  Around the world, you can look in tidepools to find representatives from many of the different types of animals. There are 21 phyla (main groups) of animals on earth. Many of these can be found in and around tidepools.

We have seen many crabs around Campanario. This is one of the most beautiful and it reminds me of the blue crabs that live near Maine. Notice the back legs. What do you think those legs are used for? Email answers to Blackberry's Mail!

 Here is a representative of the phyla arthropoda. This means jointed legs. All members of this phylum have exoskeletons. This phyla contains some of the biggest pests that show up in Maine in the spring time! What are some other animals that belong to this group? Email answers to Blackberry's Mail!

Here are the trails of some sand crabs. They live in holes in the sand. When they run (very quickly) they leave little sand pellets on their trail.

There are also land crabs in Campanario. They have a purple shell and orange legs. They come down to the beach only to lay their eggs.
Believe it or not, this is a "cousin" to the crab. It is also in the arthropod phylum. Like the crab, its babies are plankton. That means they float around in the ocean. When a barnacle finds a suitable rock, it glues its head to the rock and grows a shell. Barnacles feed by sticking their feathery legs out the "trap doors" on top and filtering the sea water for plankton.

Do you think these barnacles might end up eating some of their own babies? Why or why not? Email answers to Blackberry's Mail!
This is a mat of small sea anemones. They belong to the same phylum as jellyfish. Like jellyfish, they have tenticles with stinging cells which they use to stun (or kill) their prey. They then use the tenticles to put their food into their mouths. It turns out there is another animal, sea slugs, that eat anemoneas and then incorporate their stinging cells into their own tenticles!

These members of the phyla mollusca are limpets. Other molluscs include clams, snails, and even octopi! These are gastropods (stomach-foots), and so they are related to snails. We see lots of snails on and around the rocks here.

These limpets live like the ones in Maine. They hold onto the rock with their large foot, and scrape the algae off the rock with their tongue.

We discovered that one of the snails here lets out a milky liquid when you pick it up. After your hand touches water, it turns purple. It also stinks! What do you think this is for? Email answers to Blackberry's Mail!
Here is the underside of a limpet. You can see the mouth (tan circle at the end near Ian's foot) and one of its two antennas. Like all snails, limpets have a tongue (called a radula) which is long and rough. It feels sort of like a string of sandpaper.
This chiton is another gastropod. This one was about 5 cm long! They also move over the rocks grazing on algae with their radula. Chitons are almost impossible to remove from rocks!

This looks like a rock. Actually, the rock above the tidepool is a lot like cement. It is made of sand grains cemented together by another worm. The worm is inside holes in this "homemade rock".

 There are several phyla of worms. Ian is holding one he found sticking its head out of a tube. Animals like this need to have strong homes to protect themselves from predators!
The blackish spiny sea urchins in the crevaces of this rock belong to the phylum echinodermata. This means "spiny skin". All members of this group have spines that stick out of their skin. They also have a hydraulic system that they use to move. Starfish are the most famous member of this phyla.

This was a smaller and more delecate sea urchin which Ian and I found. This one was under a rock. We took it out for this photo, and then replaced it.

Not many animals would try to take a bite out of one of these sea urchins!
This is a picture of a "sea cucumber". It is also an echinoderm. Like other members of the phylum, it has a hydraulic system and "radial symmetry". Can you explain what radial symmetry is? Email answers to Blackberry's Mail!
This animal also has radial symmetry, a hydraulic system, and spiney skin. It is a brittle sea star. Brittle starfish capture their prey from the water. Most are "filter feeders". This means they filter small plankton from the sea water. Some brittle starfish catch small fish.
These fish belong to our phylum: chordata. This group all has a spinal cord running down their back. There is an incredible diversity of fish in the water around Campanario. Unfortunately, it is difficult getting good photographs of them! Ian and I bought a couple of disposable underwater cameras and will try to get some good photos and scan them into the computer for our web sites.
This eel was also swimming around the tidepools!
We have seen many puffer fish while snorkeling. This one washed up on the beach.
See some more of the flora and fauna of the Osa! Click on the orchid!
How do people live on the Osa? Click on the boat to see some of the people of the Osa.

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 Ian's Reports from Costa Rica

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