Species · GBIF taxon 2264603
Upside-down Jellyfish
Cassiopea andromedaAlso known as Upside-Down Jelly, Andromeda Jellyfish, Mangrove Jellyfish
These unusual jellyfish spend almost their entire lives resting upside down on the shallow sea floor, exposing their frilly, branching arms to the sunlight. This posture allows the microscopic algae living inside their tissues to photosynthesize, producing vital nutrients that sustain the jellyfish. When disturbed, they release clouds of stinging mucus into the surrounding water to deter potential predators.
MarineSymbioticBenthic
Licensed reference(c) prilfish, some rights reserved (CC BY) · cc-by
- diet
- Photosynthetic sugars from symbiotic algae, microscopic zooplankton, and organic detritus
- family
- Cassiopeidae
- threats
- Coastal development, mangrove deforestation, water pollution, and extreme ocean warming
- life Span
- 1 to 2 years
NE
Releases stinging mucus into the water; avoid swimming directly over or handling them.
Releases microscopic stinging structures called cassiosomes in mucus clouds, causing itchy rashes and burning sensations.
Do not touch or disturb the jellyfish, and wear protective footwear or a wetsuit when wading in their habitat.- Observe from above: Look for them in shallow, calm waters where they carpet the sandy bottom.
- Keep your distance: Avoid wading barefoot near them as they release stinging mucus clouds when disturbed.
- Watch the pulse: Observe the gentle, rhythmic contraction of the bell used to pump water over their arms.