Instructions
Count the tentacles of the starfish. Typically if a starfish dies, its tentacles will start to come apart. Make sure there are five tentacles.
Gently pick up the starfish and flip it over. Check to see if the tentacles are moving. Gently touch its "suckers" on the underside of the tentacles with your finger. The suckers will retract into the starfish's body if it is still alive.
Flip the starfish upside down in the water and see if it will turn himself back over, right-side up. Typically starfish have a natural defense instinct that triggers them to flip over immediately to protect themselves.
How to Tell if Your Starfish Died
Starfish are exceptional animals that live on the floor of the ocean or an aquarium. The beauty of the starfish is in it's symmetry. It's body structure is similar to a five-point star and it's skin can be colorful and leather-like. Starfish typically have a life span of five to 10 years and can grow as long as 14 inches. They are slow moving.