Giant Caribbean Sea Anemone (Condylactis gigantea)
This Sea Anemone is commonly found in the Caribbean, specifically the West Indies and the western Atlantic ranging from southern Florida through the Florida Keys.
They are usually found in lagoons or on inner reefs as either individuals or groups, but never as colonies.
In shallow water, this anemone attaches to hard objects and is also seen in turtle grass beds.
The shape of this animal’s body is related to the habitat in which it lives; it can exhibit a variety of colors: white, light blue, pink, orange, pale red, or light brown. The mouth is surrounded by 100 or more tentacles, each long and tapered with pink-, scarlet-, blue- or green-ringed tips.
These tips are usually paler than the body itself. The basal disk, or adhesive foot, is firmly attached to the substrate while the tentacles are the free moving portion.
This anemone primarily likes to sit in one location, but is capable of moving from place to place.
It moves by using its pedal disk, or attachment point, in a slow, crawling movement. Motion is not used in direct protection from predators; anemones do not run from attackers.
When placed near other anemones, this animal tends to be aggressive toward its similar neighbour. The most effective form of defense for this anemone is the use of nematocysts (stinging cells) which are the defining characteristics of cnidarians, a group that includes anemones, corals and jellyfish. The tips of the anemone’s tentacles are packed with nematocysts that contain a toxin. Using their stinging cells as “weapons”, the anemone will fire upon other anemones to conserve its space on the ocean floor. The two individuals will fight; one advancing while the other withdraws, but both may suffer tissue damage.
The nematocysts are also used in the capturing of prey. The toxin, in the concentrations found in C. gigantea, is not harmful to humans.
The Giant Caribbean Sea Anemone has many symbiotic relationships with fish and crustaceans. Some of the most common relationships include cleaner shrimp (Periclimenes anthophilus), and arrow crabs (Stenorhynchus seticornis). Animals that have symbiotic relationship with this anemone require a period of adaptation in which the animals acclimatize to each other. This adaptation allows the anemone to recognize that the other animal is not prey or a predator.
The Giant Caribbean Sea Anemone’s most important symbiotic relationship is not with another animal but a plant. Single celled algae named zooxanthellae are found living within the tissues of the anemone. They are also found living in reef-building corals, and are important to their hosts because they provide nutrients.
This anemone feeds upon fish, mussels, shrimp and other similar organisms. It will not, however, go near any of its natural predators, such as nudibranchs (seas slugs). The anemone eats food that is large in relationship to its own size; for example it will ingest prey such as adult sea urchins.
With the low frequency of large prey available, it is suggested that, like other anemones, it is not selective about what it ingests but rather eats whatever prey it encounters.
Protect Cayman’s Marine Wildlife! For more information, to share your knowledge or if you would like to get involved with the many activities in the National Trust’s Know Your Islands Program, please visit www.nationaltrust.org.ky or call 949-0121. The weekly column from the National Trust is submitted by Marnie Laing, Education Programs Manager at the Trust.
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