Plumose sea anemone
The plumose sea anemone, belonging to the genus Metridium, is notable for being one of the largest anemones in the northern hemisphere, with some species reaching heights of up to 3 1/3 feet (1 meter). Commonly referred to as feather-duster or white-plumed anemones, these creatures resemble terrestrial flowers and possess a wide, white column adorned with thousands of hair-like tentacles. They inhabit shallow coastal waters, often attaching themselves to rocks using a suction-like foot, and are known for their ability to detach and relocate for better feeding opportunities.
As carnivores, plumose sea anemones have a diet that includes plankton, fish eggs, and tiny aquatic animals, utilizing their stinging tentacles to capture prey. They reproduce both sexually and asexually, with sexual reproduction involving the release of sperm and eggs into the water, resulting in free-swimming larvae that eventually settle on the seabed. Asexually, they can bud off new individuals or regenerate if physically divided. Generally, these anemones are believed to live for over ten years, although further research is needed to confirm their longevity.
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Plumose sea anemone
Plumose anemones are some of the largest anemones in the northern hemisphere. Some species reach 3 1/3 feet (1 meter). Common names include feather–duster, fluffy, white-plumed, or frilled anemone.
Kingdom: Animalia
Phylum: Cnidaria
Class: Hexacorallia
Order: Actiniaria
Family: Metridiidae
Genus: Metridium
Species: Various (see below)
Plumose sea anemones look like the anemone, a terrestrial flower for which anemones are named. With a large, wide, white column and thousands of tiny, hair-like tentacles, these anemones are called plumose, or feathery. Several species of plumose anemones make up the Metridium genus. The giant plumose anemones (Metridium farcimen), or white-plumed anemones, are among the tallest polyps in the world and one of the largest anemones in the northern hemisphere. It has more than 200 tentacles and can grow to a height of 3 1/3 feet (1 meter). Giant plumose anemones live in subtidal or intertidal areas of North American coasts. The plumose anemone (Metridium senile) lives in the tidal pools of northern Europe and North America. Some have invaded South Africa's Western Cape Province. The 1-foot (30-centimeter) Metridium dianthus is native to the northern Atlantic and Pacific Oceans, while the Metridium canum lives in New Zealand and the southern Pacific Ocean.
This feathery, flower-like creature attaches to rocks in shallow coastal waters using its basal disc, or suction-cup-like foot. Unlike stationary anemones, the plumose sea anemone can detach itself and move to a better feeding site if necessary. They are carnivores, or animals that feed on meat. Its diet includes plankton, fish eggs, fish larvae, tiny crustaceans, shrimp, and other tiny aquatic, or water-living, animals that float by its tentacles. They also eat land animals like ants and spiders within reach of their tentacles. To eat, the plumose sea anemone opens its central cavity, sucking in prey with the water flow. It uses its stinging tentacles and poison-tipped nematocysts to paralyze its prey.
The plumose sea anemone can retract its tentacles into its body for protection. Many species retract their tentacles to avoid becoming dry when exposed to the air. When the plumose sea anemone retracts its tentacles, it appears like a blob of jelly.
These anemones may reproduce sexually or asexually. In sexual reproduction, the anemone releases thousands of sperm and eggs into the water. Only a few eggs are fertilized and become free-swimming larvae. These larvae look like tiny jellyfish. They search the water for a place to plant themselves. The larvae settle on the seabed and mature into full-grown anemones. In asexual, or independent, reproduction, a single plumose sea anemone buds, or sprouts a new section which eventually splits off and becomes a separate organism. A plumose sea anemone may also reproduce asexually by binary fission, or simple division, but needs the help of a human or predator. If cut in half, both halves can regenerate into new individuals.
Plumose sea anemones are assumed to live ten years or longer, though longevity studies are needed.
Bibliography
"Giant Plumose Anemone." Georgia Aquarium, www.georgiaaquarium.org/animal/giant-plumose-anemone. Accessed 15 Apr. 2024.
"Plumose Anemone." University of Puget Sound, www.pugetsound.edu/puget-sound-museum-natural-history/exhibits/marine-panel/plumose-anemone. Accessed 15 Apr. 2024.