upside-down jelly@04Dec2009

upside-down jelly 04Dec2009 - Southern Islands ~ Siingapore from BeachBum on Vimeo.

These upside-down jelly(fish) are commonly seen around mangrove mudflats and beaches around Singapore. They turn themselves upside down and rest on the bottom substrate pulsating along all the time to enable the symbiotic algae in their body tissues to receive sunlight from above. These symbiotic algae use the sunlight to make food...some of which benefits the jelly. When upside down, the jellies are frequently mistaken for anemones.

The jelly also uses it's stinging tentacles to catch plankton for food.

Crabs sometimes use the upside down jellies (and some types of anemones as well) to protect themselves by carrying them on their shells.

Size : about 6cm across.

Find out more about this and other types of jellyfish here :
WildSingapore's WildFacts on Cassiopea

Wikipedia on Cassiopea
Jellyfish Facts on Cassiopea
Monterey Bay Aquarium's link on the Cassiopea
Interesting Facts about Jellyfish
The largest jellyfish
The most poisonous jellyfish
What do Jellyfish eat?
Jellyfish species