Turritopsis dohrnii is a species of jelly fish that is biologically immortal

• Medusa diameter: 4.5mm
• Habitat: most oceans and seas
• Tentacles: 80-90
• Average lifespan: immortal

Turritopsis dohrnii, the immortal jellyfish, is a species of small, biologically immortal jellyfish found in the Mediterranean Sea and in the waters of Japan. It is one of the few known cases of animals capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary individual.