True jellyfish · Semaeostomeae · Pelagiidae

Mauve Stinger

Pelagia noctiluca

Not Evaluated

It has not yet been assessed against the IUCN criteria. See full glossary

It is bioluminescent, hence its scientific name — noctiluca means 'night light'. It is one of the few jellyfish that skips the polyp stage fixed to the sea floor.

Size

3 cm – 12 cm

Lifespan

1 years

Diet

Carnivore

Feeds mainly on other animals.

Activity

Nocturnal

Active mainly at night.

Social structure

Colony

Lives in large concentrations, often for breeding reasons.

Sighting difficulty

Unknown

OceanCarnivore Nocturnal Colonial Ocean Cnidarian

29countries 41parks 79dive sites1same family

Fun facts

Its scientific name means 'night light', after its bioluminescence.
It goes straight from planktonic larva to young medusa, with no fixed polyp stage.
It can form large ocean swarms, especially in the Mediterranean.
It is the jellyfish responsible for most of the ruined bathing days in the Mediterranean, and its sting is painful and leaves a mark for weeks.
It has no polyp stage. Unlike almost all jellyfish, which alternate a fixed stage on the bottom with the swimming medusa, this one develops directly from egg to medusa in the open sea.
And that explains its behaviour: since it does not depend on a substrate, its populations are entirely oceanic and reach the coast driven by wind and currents, in unpredictable waves.
It is bioluminescent, hence its name: when disturbed it gives off bluish flashes, visible at night in the wake of ships.
Its outbreaks in the Mediterranean have become more frequent, and are linked to warming waters, the overfishing of its predators and competitors, and changes in the currents.
It eats zooplankton and fish eggs and larvae, which makes it a direct competitor of the very fish whose overfishing favours its spread.

Life cycle & biology

Skeleton type: Invertebrate - no skeleton, gelatinous body (cnidarian)
Habitat & environment: Temperate and tropical oceanic waters worldwide, especially abundant in the Mediterranean
Birth weight: A microscopic planula larva that develops straight into an ephyra (the juvenile medusa stage), with no bottom-living polyp phase
Size at birth: A microscopic ephyra as it develops from the planula
Sexual maturity: It matures within its single annual life cycle
Gestation / incubation: No incubation; the fertilised egg develops straight into a planula and then an ephyra
Litter / clutch size: It breeds by releasing gametes into the water for external fertilisation; the sources consulted put no figure on the number of eggs