Why Isn't a Jellyfish a Fish?

What Crafty Clover says in this video

Intro

Hey there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why isn't a jellyfish a fish?

The Big Idea

A fish has a backbone, gills, and usually scales. A jellyfish has none of those! A jelly is a soft animal called a cnidarian. That makes it a cousin of corals and sea anemones, not a cousin of tuna. The word fish just got stuck on its name. Scientists group animals by body plan, not by nickname.

No Backbone

Step one: no backbone. Fish have a stiff backbone inside. A jelly has no bones at all. It is also missing gills and scales, so it is not built like a fish. It breathes by soaking up oxygen through its thin body.

A Soft Bell Pulses

Step two: a soft bell pulses. A jelly squeezes its bell to push water out, and that gently moves it along. Mostly, though, it drifts with the ocean currents.

Stinging Tentacles

Step three: tentacles trail and sting. Long tentacles hang down, with stinging cells that catch small food like tiny shrimp. And a jelly's body is mostly water, which is why it is so wobbly and see-through.

A Closer Look

Let's take a closer look at a fish and a jelly! A fish has a backbone. A jelly has no backbone at all. Its body is mostly water. And it is a cousin of corals and anemones.

Quick Facts

Quick facts! Names can trick you. Starfish and crayfish are not fish either. Jellies are older than the dinosaurs. And scientists group animals by body plan, not by nickname.

Think Like a Scientist

Now, think like a scientist! Look up pictures of a fish and a jellyfish. List the parts a fish has. Which of those does a jelly have? What three fish parts is a jelly missing? And why do scientists care about body plans?

Outro

Jellyfish is just a nickname. It is a drifting cousin of coral, not a fish. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!