Magnificent sea anemone
Heteractis magnifica (known variously as magnificent sea anemone or Ritteri anemone) is a species of sea anemone that lives in the Indo-Pacific area, and can grow up to 1 metre (3 feet) in diameter
in the wild. It can be kept in aquaria but is considered one of the
most challenging species to keep healthy. They require very strong
lighting and very high chaotic flow. They will not survive in tanks
with any presence of nitrites or nitrates. If they are healthy and kept
well fed they will grow very rapidly. H. magnifica consumes both vertebrates and invertebrates, including fish and crustaceans.
It is often found in association with anemone fish, or clownfish, such as the cinnamon (Melanopus), Clarki (Clarkii), false Percula (Ocellaris), Maldives (Nigripes), Percula (Percula), and the pink skunk (Perideraion).
H. magnifica was featured in the Pixar Animations film Finding Nemo.
Information from Wikepedia - http://en.wikipedia.org/wiki/Magnificent_sea_anemone