Jack Costello, Biologist: Why Jellyfish Swim

Length: 
6:18

Jack Costello studies how jellyfish move and feed. He dives to videotape moon jellies swimming and observes that they don’t really move much. With this in mind, he seeks to answer the question: “why do jellyfish spend their time swimming?” And, in fact, as Costello observes, they are not really designed for making forward progress. He designed an experiment to look at how jellyfish swimming creates currents. Injecting particles into the water reveals what the jellyfish are doing: they are creating currents that bring particles to the tentacles so they can capture their prey. And each jellyfish does this differently, allowing them to capture different prey.

Next Generation Science Standards for this Video

Scientific experiments provide clues to understanding the function of jellyfish swimming. The jellyfish’s shape is not designed for fast movement but rather to create currents to bring in food.

Jack Costello scuba dives to study jellyfish in the field and observes and conducts experiments on them in the lab.

The jellyfish’s shape is not designed for fast movement but rather to create currents to bring in food.

Jack Costello scuba dives to study jellyfish in the field and conducts experiments on them in the lab.

Scientist in this video

They are creatures so simple that scientists once considered them plants. But they're the critical group to study, if you want to understand motion and behavior. -- Jack Costello

Community Developed Lesson Plans to Use with this Video