Last summer, my family and I took a trip to Jamaica. My favorite part of the trip was when we went to a place called the Luminous Lagoon. We ate dinner and waited for the sun to go down. Then we boarded a boat and went out into the lagoon. That’s when the magic started. At first we could not see very much in the darkness except for the stars in the sky. After a few minutes, however, I noticed some fish swimming in the water. They didn’t look like ordinary fish. These fish were glowing! Our guide explained that the glow came from tiny creatures in the water called dinoflagellates. These little animals are not visible to us, but their bodies produce light using something called bioluminescence, just like fireflies. There are so many of these creatures in Luminous Lagoon that the water around them seems to glow.

After our guide explained these facts to us, he told us to put our hands in the water. I was not sure if it would work, but I tried it. When I did, my hand looked like it belonged to a superhero! It was glowing bright blue. I hope someday I get to return to the Luminous Lagoon. The lights in the water were much more entertaining than the ones in the sky.

Problem:The Greek prefix dinos- means “whirling” and the Latin root word flagellum means “whip”. What does dinoflagellate most likely mean as it is used in the passage?

the production of light from an organism’s body

the study of creatures that live in the ocean

to move around underwater water like a fish

an organism with a whip-like part it uses to move around in the water