Sea jellies are mesmerizing and graceful animals that pulse through the water column. With limited control over their movement they drift with the ocean currents. Sea jellies are living fossils as they have existed for at least 500 million years and have barely changed in all that time. Their body is bell shaped is made up of a gelatinous mass which is 95% water.
They are a key part of the ocean food chain contributing to the diets of many predators. Most jellyfish just drift and passively hunt for their prey. Sea jellies are all radially symmetrical which means they can be cut in half from top to bottom around a central point and the two sides would be roughly the same (like a pie!).
Breeding sea jellies at S.E.A. Aquarium
At S.E.A. Aquarium we have 6 habitats that house a diverse collection of sea jellies. We are currently breeding the following species:
- Moon sea jelly (Aurelia aurita)
- Upside-down sea jelly (Cassiopea species)
- Indonesian sea nettle (Chrysaora pacifica)
- Japanese sea nettles (Chrysaora melanaster)
- White spotted lagoon sea jellies (Mastigias papua)
Sea jellies have a very short lifespan, so it is essential for us to determine the best conditions for each species to reproduce. We can therefore repopulate our habitats and minimize the need to collect sea jellies from the wild.
Sea jelly reproduction involves several different stages. The males and females spawn and produce tiny free-swimming larvae called ‘planulae’. The planulae hook onto free surfaces and develop into polyps that look like tiny sea anemones, a stage in which they can remain for several months or years.
Eventually the polyp will clone itself and then grow and develop into an adult jellyfish. At S.E.A. Aquarium we have successfully bred a large number of sea jellies. Parts of the process can be complex and therefore require care and attention from our specialist aquarist team.
Learn more about the role of a sea jelly aquarist at S.E.A Aquarium.