Order: Pennatulacea, Phylum: Cnidaria
Behold the beautiful Sea Pen!
These animals are closely related to jellyfish. They are part of Class Anthozoa while jellyfish are part of Class Scyphozoa. Unlike jellyfish, anthozoans never go through a free-floating medusa stage, they remain polyps throughout their lifecycle.
Although they are sedentary, sea pens still undergo sexual reproduction. Individuals release eggs and sperm in coordination at certain points during the year.
Analysis of annual sea pen growth rings has shown that these animals can live for upwards of 100 years!