Giant Anemone

Notice the Yellowline Arrow Crab below the Anemone

The giant caribbean sea anemone is one of the most beautiful reef organisms.  They are the largest of the anemones, growing to be about six to 12 inches across.  The giant anemone can be identified by its long tenticles with enlarged tips.  These anemones come in a variety of colors including white, blue, green, yellow, and brown. Often the tips of the anemone are different colors from the body; they may be pink, lavender, yellow, chartreuse, or white.  The tips, however, do not always differ in color, as evident by the giant anemone to the left.

There is a common misconception that anemones are either plants or corals. They are, however, neither.  Corals and anemones are closely related though, belonging to the same phylum Cnidaria.  Cnidarians have a simple structure consisting of a cup-shaped body, a central opening that is both the mouth and anus, and numerous tenticles that surround the central opening.  Cnidarians may live attached to substrate or as free swimming organisms.  When the animal is attached to substrate it is called a polyp, and if it is free swimming it is called a medusa.  Often a cnidarian's life cycle consists of both a polyp and a medusa stage.  Additionally, cnidarians may also live in colonies or as separate individuals.  Another characteristic of cnidarians is that they all have stinging capsules called nematocysts that are used for protection and aid in capturing food.

The giant anemone's scientific name is Condylactis gigantea and it obviously belongs to the order Actiniaria, or sea anemones.  All members of the order Actiniaria are individual animals that are attatched to some sort of substrate.  They all have long tentacles with nematocysts that help capture their prey and a slit-like mouth in the center of the body that engulfs the food once it is passed down.  Anemones can move, but they do so only when necessary and it is a very, very slow process.  Also, anemones are often involved in symbiotic relationships with many different reef creatures including fish, shrimp, and crabs.

The giant anemone can be found throughout the tropical waters of the Atlantic.  They are most common in south Florida, throughout the Caribbean, and Bermuda.  Their diet consists of small particulate matter and small organisms that come into contact with their stinging nematocysts.  Like all anemones, this species forms many different symbiotic relationships with reef creatures.  The most common of which is with cleaner shrimps, arrow crabs, and juvenile wrasses.  Zooxanthellae also form a symbiotic relationship with this anemone and provide essential nutrients to its partner.

These anemones can reproduce either sexually or asexually.  They also have the potential to be either dioecious or hermaphroditic.  No matter the process used for reproduction, all methods lead to embryos that hatch into larvae.  The medusa larvae then settle onto a suitable substrate where they attach and begin to grown into adult giant anemones.

References: Humann, Paul, and Ned Deloach. Reef Creature: Identification : Florida, Caribbean, Bahamas. Jacksonville: New World Publ, 1996. 66, 90-91. Print.; Zahra, Marianna. "Giant Caribbean Sea Anemone (Condylactis Gigantea)." Octopus, Squid, Cuttlefish, and Nautilus - The Cephalopod Page. Web. 27 Jan. 2011. <http://www.thecephalopodpage.org/MarineInvertebrateZoology/Condylactisgigantea.html>.