Species group · True jellyfish

Jellyfish

WAnimals has 6 species of jellyfish, spread across 5 families (Cassiopeidae, Cyaneidae, Pelagiidae, Periphyllidae, Ulmaridae).

6 species
5 families
116 countries
124 parks
Length
3 cm – 2.5 m
Lifespan
1 – 30 years

Ranges calculated from the entries that record the figure, not from all 6.

All 6 species of jellyfish on WAnimals

Each one has its own full entry. This group does not replace them: it brings them together.

Conservation status

6 Not Evaluated

No species documented in this group is genuinely at risk according to the IUCN, with the data available today.

See the global conservation status

Where they live

Recorded in 116 countries. The ones with the most species in the group:

Where to see them

Did you know…

  • It is the largest jellyfish in the world. The largest recorded specimen, stranded in Massachusetts Bay in 1870, had a bell 2.3 metres across and tentacles almost 37 metres long: longer than a blue whale.

    From Lion's Mane Jellyfish

  • Its tentacles, up to 1,200 of them, hang in eight groups forming the dense curtain that gives it the name lion's mane.

    From Lion's Mane Jellyfish

  • Despite its size it lives only a year: the medusa appears in spring, grows all summer and dies in autumn.

    From Lion's Mane Jellyfish

  • Its scientific name means 'night light', after its bioluminescence.

    From Mauve Stinger

  • It goes straight from planktonic larva to young medusa, with no fixed polyp stage.

    From Mauve Stinger

  • It can form large ocean swarms, especially in the Mediterranean.

    From Mauve Stinger

  • It eats zooplankton, small crustaceans and fish larvae.

    From Moon Jellyfish

  • It lives in temperate coastal waters and estuaries of almost every ocean in the world.

    From Moon Jellyfish

Ecosystems

See every species group · Explore the species one by one