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  1. 23 Photo by Kylie Pitt

Jelly Blubber

Catostylus mosaicus


  • Colour: Its large bell varies from bright blue in the north of Australia to creamy white or brown in the southern part of its range.
  • Eight cauliflower-like tentacles hang down from its bell.
  • Size: Its bell is up to 35 cm across.


  • Diet: plankton, small fish larvae and tiny crustaceans. It uses the stinging cells on its tentacles to capture its prey and then ingests its food through the many tiny openings in its tentacles.
  • Movement: it is carried along by ocean currents and can also actively move by pulsing and contracting its bell.
  • Breeding: females collect some of the sperm that males release into the surrounding water to fertilise their eggs. The eggs form larvae that swim away from the mother, settle on a hard surface and then change into tiny polyps (about 2 mm tall). Juvenile jellyfish then bud from the top of the polyps and grow into adult jellyfish. 

What to Observe

  • Presence (to establish the first and last sighting of the season)

ClimateWatch Science Advisor

We don’t yet know whether water temperature affects where jellyfish are found. Data on their distribution will help determine whether their range is changing and how climate change may impact their distribution.

When To Look

  • All year round, but they are most likely to be abundant in the warmer months, around summer time.

Where To Look

  • Around the coast of Queensland, New South Wales and Victoria.
  • In coastal waters and the mouths of rivers that open into the sea.
  • Along beaches where it might be washed up.

Jelly Blubber Occurrence Map ALA


Brusca RC and Brusca GJ 1990. Invertebrates. Sinauer Associates Inc. Sunderland, Massachusetts.

Covacevich J, Davie P and Pearn J (editors) 1987. Toxic Plants and animals: a guide for Australia. Queensland Museum, Brisbane.

  1. Search Species

  1. What Else?

    Versuriga anadyomene: tends to be larger than most Jelly Blubbers, with a bell up to 60 cm across.

  1. Did You Know?

    It does not need a respiratory system to breath as its skin is so thin that oxygen from the water can diffuse in to the body.

    The Jelly Blubber is the most commonly seen jellyfish along the east-coast of Australia.