Sea Star Suppers: What's Their Favorite Food?

Peabody Charter School
Teacher: Linnie Aikens Avila
Scientists: Dr. Juliann Aukema, Dr. Marissa Baskett, and Dr. Brad McRae

Introduction:

The sea star is quite an amazing animal! A sea star is an invertebrate and a predator. As a predator it hunts its prey in a very original way. It catches its food with tiny suckers on its numerous legs. The sea star turns its stomach inside out to eat its meal. Their diet consists of mussels and snails, or fish and many other prey.

Question:

Does the sea star like to eat mussels or snails best?

Methods:

When we first began the experiment we filled four different tanks. The first tank had a sea star with small and large mussels. The second tank had a sea star with small and large snails. The third tank had a sea star with mussels and snails. The fourth tank had no sea stars but it had mussels and snails. We checked if there were any empty shells in the tank.

Results:

We found that the sea stars ate only mussels, not snails. In bucket one there were a sea star and mussels. The sea star ate just 2 mussels. In bucket two there was just a sea star and snails. It ate zero snails. In bucket three there were mussels and snails and a sea star. The sea star ate 2 mussels and zero snails. In the fourth bucket there was not a sea star. There was one dead mussel and no dead snails.

Conclusion:

The sea stars prefer small mussels versus big mussels, and they prefer mussels to snails. We think that the dead mussel was an exception because when we put it in the tank it was already sick.