The Immortal Jellyfish Quiz

Turritopsis dohrnii: The Biologically Immortal Jellyfish

• Turritopsis dohrnii is a species of small, biologically immortal jellyfish found worldwide in temperate to tropic waters.
• 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.
• T. dohrnii begin their lives as tiny, free-swimming larvae known as planulae. As a planula settles down, it gives rise to a colony of polyps that are attached to the sea floor.
• If the T. dohrnii jellyfish is exposed to environmental stress, physical assault, or is sick or old, it can revert to the polyp stage, forming a new polyp colony.
• Theoretically, this process can go on indefinitely, effectively rendering the jellyfish biologically immortal, although in practice individuals can still die.
• T. dohrnii is an important target of basic biological, aging, and pharmaceutical research due to its capability of biological immortality with no maximum lifespan.
• The medusa of Turritopsis dohrnii is bell-shaped, with a maximum diameter of about 4.5 millimetres (0.18 in) and is about as tall as it is wide.
• Turritopsis dohrnii also has a bottom-living polyp form, or hydroid, which consists of stolons that run along the substrate and upright branches with feeding polyps that can produce medusa buds.
• Turritopsis is believed to have originated in the Pacific, but has spread all over the world through trans-Arctic migrations.
• The eggs develop in gonads of female medusae, which are located in the walls of the manubrium (stomach).
• Turritopsis dohrnii are a carnivorous species that commonly feed on zooplankton. Their diet mainly consists of plankton, fish eggs, and small mollusks.
• T. dohrnii is generally found living in temperate to tropical waters. They can be found in marinas or docks, on vessel hulls, and on the ocean floor.