Chapter 29, Problem 10STP

Summary Introduction

To analyze:

The way a sea star opens an oyster by relating the process to the given structures.

Introduction:

Echinoderms are marine creatures, including sea stars, sea urchins, brittle stars, sea urchins, sea lilies, sea cucumbers and sea urchins. Echinoderms are deuterostomes because their mouth differs from the rest of the gastrointestinal tract. Till now almost 6000 living species of echinoderms have been identified.

Explanation of Solution

When some species of starfish find a special treat, such as a mussel or an oyster, they spread their stomach out of their mouths to digest the soft parts of their predators. This creates a soup-like substance that they slurp back into their body to finish the meal. Sea stars are important predators in marine ecosystems, feeding on clams and other bivalves. Single tube feet will exert a pull of 0.25 to 0.30 N. This is equivalent to the force needed to lift between 25 and 30 large paper clips. Since a sea star may have as many as 2,000 tube feet, it may exert quite a great force when it crawls or opens mollusks for food.

Conclusion

Thus, the sea stars can move with the help of tube feet and ampulla. They can open an oyster with the help of their tube feet which exert force.