Blue man hair, funky shag carpet or Cookie Monster. Not close — only in our imagination. Magnified, it’s hard to tell what we are looking at. Taking a closer look, sometimes reveals what we need to see. Realizing this is a organism living under the sea — surviving on fish and shrimp. Further investigation provides complexities unknown unless we looked even closer.
The mouth is in the middle of the oral disc surrounded by tentacles armed with many cnidocytes, which are cells that function as a defense and as a means to capture prey. Cnidocytes contain nematocyst, capsule-like organelles capable of everting, giving phylum Cnidaria its name.[5] The cnidae that sting are called nematocysts. Each nematocyst contains a small vesicle filled with toxins (actinoporins), an inner filament, and an external sensory hair. When the hair is touched it mechanically triggers the cell explosion, a harpoon-like structure which attaches to organisms that trigger it, and injects a dose of poison in the flesh of the aggressor or prey. This gives the anemone its characteristic sticky feeling.
A sea anemone alive and well at the Maritime Aquarium, South Norwalk, CT.
Images: © Karl Heine 2010
