Jellyfish Are Fascinating Creatures That Belong To The Phylum Cnidaria. Stock Photo

Jellyfish have a gelatinous, umbrella-shaped bell and long, trailing tentacles. The bell is typically translucent and can vary in size from just a few centimeters to several meters in diameter, depending on the species. The tentacles contain specialized cells called cnidocytes, which house stinging structures called nematocysts used for defense and capturing prey.