Thursday, Oct. 9, 2003
* Japanese name: Yoroiisoginchaku
* Scientific name:Anthopleura japonica
* Description: Anemones are marine invertebrates, cylindrical animals with rings of tentacles on the upper surface. They are related to jellyfish and corals. Aggregating anemones grow up to 3 cm in diameter and can have a brilliant green sheen. The tentacles are arranged in circles and stout at the base; the mouth is at the center of the upper surface.
* Where to find them: Attached to rocks in the low and middle intertidal zone (the part of the beach daily covered by the tides). Anemones can also be found higher up the beach in rock pools. If an anemone is not in a rock pool when the tide goes out, it will draw its tentacles in and close up, preventing excessive water loss and making the anemone difficult to see. They also live in subtidal zones, at depths of up to 25 meters. Aggregating anemones (which are found all over the world) often live in groups, hence their name.
* Food: Mainly small planktonic organisms, microscopic animals and plants that live in the sea. Anemones catch their food in their sticky tentacles and draw it into their mouth. They will also eat bits of dead organisms such as jellyfish that might be floating about, and the larvae of all sorts of animals.
* Special features: Like corals, the aggregating anemone forms symbiotic relationships with other organisms. These are usually algae (plants), or dinoflagellates (single-celled organisms that are in neither the plant nor animal kingdoms) that live in the anemone's body. The presence of these symbiotic organisms affects the color of the anemone. If they have no symbionts, they are white. Aggregating anemones can form large groups, and all individuals within a group are genetically identical: they are clones of each other. Reproduction is not spectacular in these animals: When an anemone gets to a certain size (about 3 cm) it simply splits in two.