These are simple invertebrates from the Cnidaria phylum.
Jellyfish body parts radiate from a central axis. Jellyfish have an elementary nervous system, or nerve net, that allows them to smell, detect light, and respond to other stimuli.
Jellyfish tentacles have the ability to sting.
Jellyfish are soft because they are composed of 95% water and most of a translucent substance called mesoglea.
Cnidocytes:
Because their bodies are so delicate, they rely on thousands of venom-containing stinging cells called cnidocytes for protection and pre-capture.
Even baby jellyfish the size of a pencil eraser are capable of stinging.
The Lion's mane jelly, the largest species of jelly, has tentacles that can extend more than 100 feet longer than a blue whale.
The majority of the stinging cells are found in these tentacles, though some species have them on their belly as well.
The reaction is intended to serve as a defence response as well as to capture prey.
Jellyfish are carnivorous, capturing alga, zooplankton, and crustaceans with their stingers.
Its tentacles contain weapons that are used to immobilize prey.
Each jellyfish tentacle contains thousands of cnidoblasts, which are nematocyst-containing cells.
They shoot when they are touched.
The stinging thread at the tip of nematocysts enters the skin and injects venom.
The venom is a neurotoxin that is meant to paralyze prey but is painful to humans.
