Metridium Fields Forever

By Lance Morgan

Giant plumose anemones (Metridium farcimen) are spectacularly beautiful, unless you have issues with cauliflower. Densely packed, they looked superficially like heads of cauliflower bunched together. (Roasted with olive oil and garlic is one way to make it go down easier, but I digress).

Piloting the Deep Worker submarine through North Moresby Gulley at 450 feet I came across a large rock outcropping festooned with these wonderful animals. As far as I could see, white and orange anemones, a foot or more in height, dominated the rock wall. Interspersed were lots of colorful rockfishes which used the crevices beneath the plumes to play a game of hide and seek.

These sea anemones are sit and wait predators, voracious ones at that if you are living in the plankton. Related to corals and jellyfish, metridium anemones are part of the Phylum Cnidaria. They all have in common a feeding method that uses specialized stinging cells in their tentacles to stun and capture their prey. Scientists believe that metridium’s broad plumes form current eddies that aid in their feeding.

While many anemones reproduce by “cloning”, whereby the animal actually splits into two identical polyps, we observed these individuals spawning in large, gelatinous clouds. Individual animals can live to be several centuries old, though no one is certain exactly how long they live. Closely related deep sea corals can live thousands of years, making them the oldest surviving animals we know on Earth. Metridium are susceptible to being eaten by sea slugs (nudibranchs) and leather sea stars; I would DEFINTITELY need a lot of olive oil and garlic.