In this video, we explore how the fingernail-sized Irukandji jellyfish can cause excruciating pain, organ failure, and even death with just a single sting.

Jellyfish can produce offspring both sexually ... for the comblike rows of tiny paddles they use to swim, they tend to be small, delicate, and hard to study. They come in an array of weird body ...

Jellyfish are known for drifting to and fro ... forth across the lake they mix its waters—and churn the nutrients and small organisms that form the base of the food chain.