TAXONOMY
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Subclass: Hexacorallia (includes stony corals, all sea anemones, tube anemones, and zoanthids)
Order: Actiniaria (sea anemones)
Family: Actiniidae (largest family of sea anemones)

Genus/species: Anthopleura elegantissima

GENERAL CHARACTERISTICS: Most are olive to bright green (depending on the species of algal symbionts present) with tentacles tipped in pink. The oral disk has approximately 100 tentacles in three or four rows around its margins. Those that are deficient in photosynthetically active radiation, such as under docks or in caves, lack symbionts and are pale yellow to white in color.
Disc 2-3 cm (0.78-1.2 in) across, under water.

Aggregating Anemones23710001752_0cf3a8e808_k

DISTRIBUTION/HABITAT: Common in tide pools. The body of the anemone is firmly attached to rock substrate and detritus and sand adheres to the column almost covering them.

DIET IN THE WILD: Capture tiny crustaceans and other animals past their tentacles using their stinging nematocysts (also called cnidocytes) on the surface of their tentacles.

REPRODUCTION: To clone themselves, anemones split in half tearing themselves apart (asexual reproduction). Aggregating anemones also reproduce sexually by broadcasting eggs and sperm.

PREDATORS: Their are few known predators but include the nudibranch Aeolidia papillosa, leather star Dermasterias imbricata and mosshead sculpin Clinocottus globiceps.

REMARKS: When one colony of genetically identical polyps encounters a different genetic colony, the two will wage territorial battles. A. elegantissima has specialized tentacles called acrorhagi to deter non identical colonies from encroaching on their space. It extends the acrorhagi to attack the competing anemone with nematocytes leaving behind a ‘peel’ of the ectoderm and nematocysts that causes tissue necrosis in the receiving animal.

References

California Academy of Sciences Tidepool

Ron’s flickr  https://www.flickr.com/photos/cas_docents/23710001752/in/album-72157625127345346/

Encyclopedia of Life  eol.org/data_objects/27560182

Ron’s WordPress shortlink  http://wp.me/p1DZ4b-1D1

Monterey Bay Aquarium www.montereybayaquarium.org/animal-guide/invertebrates/ag…

Slatter Museum of the U. of Puget Sound www.pugetsound.edu/academics/academic-resources/slater-mu…