Jellyfish typically use their tentacles to propel themselves towards the surface and disappear off the screen. Jellyfish are passive enemies, but they deal damage on contact. Jellyfish are not edible and can not be eaten by Ecco. They can be defeated with Ecco's charge attack, the Charge Sonar, or the Death Sonar.
Ecco the Dolphin
Common Jellyfish are widespread throughout the Ecco seas, occuring in all the original games. It is the simple jellyfish, dealing low damage and swimming up to the surface. It is called the Membrane Jellyfish in Ecco: Defender of the Future, where it phases in and out of visibility, making it hard to see.
Tides of Time
Defender of the Future
This large jellyfish occurs in Ecco: Defender of the Future. It is a damaging species, but is not as transparent and can be seen further away.
This lethal jellyfish appears in Ecco: Defender of the Future and poisons on contact. The only way to cure the sting is to eat a special fish that hurts Ecco but heals the poison. This jellyfish can be defeated like normal jellyfish, with a charge or sonar to its dome.