The Ritteri anemone, also known as the magnificent sea anemone, is a spectacular species living in the shallow waters of the Indo-Pacific region. It prefers areas where the substrate is hard and sunlight is plentiful, so it is very rarely found in waters deeper than 20 m.
The Ritteri anemone is large, having a flared oral disc that usually measures 20-50 cm in diameter, but can grow to around 1 meter. The base, the tentacles and the oral cavity of the magnificent anemone are of the same color, usually cream or white, but the tentacles can be of any color from white and green to blue, pink and orange. The tentacles are long, usually measuring 6-8 cm and they are distributed in concentric circles. The tentacles end in finger-like tips that are often of a different, brighter color than the rest of the tentacle. Magnificent anemones are not peaceful, but they live in symbiosis not only with algae, but with numerous larger species such as shrimps and fish, especially colorful species such as clownfish or anemonefish that have bodies covered in a special mucus that protects the fish against the stinging toxin released by its host. When the anemone feels threatened, its tentacles are almost completely withdrawn into the base, but it may also choose to defend itself by stinging the attacker with its tentacles. Though they live on the substrate attached to a suitable spot, they are also able to move, following ideal food and light conditions.
These anemones have not one, but two highly efficient feeding methods, used simultaneously: they use their tentacles to capture prey such as juvenile fish and small invertebrates and they also use the microscopic zooxanthellae algae that live in symbiosis with them to obtain nutrients from the byproducts of the photosynthesis carried out by the algae such as carbohydrates and glucose.
Like many other anemone species, magnificent sea anemone can reproduce sexually as well as asexually. Sexual proliferation takes place by means of spawning – the males and females release their gametes into the water at the same time, fertilization occurring externally, in the water, then the fertilized eggs hatching into tiny larvae that float until they are sufficiently developed to settle. Asexual reproduction takes place via scissiparity – the Ritteri anemone divides itself starting from the mouth or from the foot to form two individuals.