Starfish are not actually fish, but rather echinoderms.

Here's why:

* Echinoderms are a phylum of marine animals that have radial symmetry (meaning they have body parts arranged around a central axis) and a spiny skin.

* Fish are vertebrates, meaning they have a backbone.

So, while they live in the ocean and have the word "fish" in their name, starfish are actually more closely related to sea urchins and sea cucumbers than they are to fish.