This means that they live attached to the bottom with their tentacles and mouth pointing up. The northern Red Anemone is a good example of an Anthozoan. Some are solitary, meaning that they live alone, but some are colonial, meaning that they live in groups, connected together with living tissue, and share food resources. The jellies drift along in the water generally with the mouth and tentacles pointing down. We call this a medusoid body form.
Some jellies are extremely venomous to humans.
Some can even kill people with enough contact of tentacle on bare skin, but most are not that dangerous, producing only a mild rash similar to that caused by poison ivy. The Lion's Mane Jelly is a venomous Scyphozoan which can sting people with its long tentacles. All illustrations, images and text on this page copyright 1997 Oceanic Research Group. For non-profit educational uses only.