Details
Cassiopea andromeda
The upside-down jellyfish rests bell-down on shallow bottoms. Its upward-facing arms hold symbiotic algae, letting it use both sunlight and suspended food.
Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)
It inhabits warm coasts, lagoons, mangrove shallows, and reefs in the Indian, Pacific, and Atlantic oceans. Sunlit, sheltered sand or mud is typical.
Bell diameter 8-30 cm; weight 20-500 g. The flattened bell lies downward while branching oral arms spread upward. Brown or green tones come largely from symbiotic algae.
Diurnal and loosely gregarious, it lies inverted to expose algae to light. Pulsing moves water, and mucus can be released into the surrounding water.
A filter-feeder, it catches tiny particles and plankton with oral arms and mucus. Photosynthetic products from algae also provide major nutrition.
Sexual reproduction produces larvae that settle as polyps. Polyps release small jellyfish that grow on shallow bottoms.
It is listed as Least Concern. Dense blooms can cause mild stinging sensations for swimmers in shallow water.
