Green Sea Anemone
Anthopleura xanthogrammica
Green sea anemones are invertebrates commonly found in North and Central America. They catch their food using stinging cells in their tentacles. Anemones attach to the ground using a muscular foot and can even hold on in strong ocean currents. They also help small crabs find new homes by expelling the leftover shells of the snails they eat! affect the ocean immensely.
Credit: Alice Hsieh
SPECIES IN DETAIL
Green Sea Anemone
Anthopleura xanthogrammica
CONSERVATION STATUS: Data deficient
CLIMATE CHANGE: Uncertain
At the Aquarium
Northern Pacific Gallery
Geographic Distribution
Green sea anemones are found primarily along the west coast of North and Central America. They are also found in Hudson Bay, Canada and the eastern coast of Russia.
Habitat
Usually found in tide pools, Green sea anemones attach to rocks, coral, or man-made structures (like concrete). They thrive in cold waters of about 15.0-22.2 celsius (59.0-72.0 degrees fahrenheit). These creatures are about 0-5m (0-15 feet) in the water.
Physical Characteristics
Green sea anemones have tube-like body structures, with at least six rings of tentacles surrounding the mouth. The column diameter can be up to 17 cm and they can grow up to 30 cm tall. They have a basal pedal disk that allows them to attach themselves to the substrate. The column ranges in color from dark green to brown with irregular tubercles on the surface.The disk and tentacles are green, blue or white depending on the amount of sunlight they receive. With more exposure to sunlight, their green coloration intensifies.
Size
Height: Can grow up to 30 centimeters (12 in) high Width:17 centimeters (7 in) in column diameter
Diet
The Green sea anemone diet consists of detached mussels, small fish, crabs, and sea urchins. They paralyze their prey with the nematocysts (small venomous stinging cells) on their tentacles, and use their tentacles to bring the food directly into the mouth. Once the food is digested, the waste products are expelled out of the mouth. Any shells from their diet are ejected and used as shelter such as the blue band hermit crabs. At the Aquarium of the Pacific, we feed the green sea anemones small cut up fish, crabs, and shrimp.
Reproduction
Spawning green sea anemones usually happen in warmer waters so breeding seasons are during the late summer and early fall. Reproduction occurs through external fertilization. Females will release thousands of eggs, while males will release sperm into the water column. The resulting planktonic larvae will then drift and eventually settle on the seafloor. Green sea anemones reach sexual maturity at five to ten years old. There can be anywhere from 3,000-9,000 offspring.They are broadcast spawners since there is no parental involvement past that production of gametes stage.
Behavior
Green sea anemones move very little in their lifetime and prefer to live in solitude, however, they are commonly found in small groups of up to fourteen individuals. There is usually an empty space between adjacent colonies of anemones. If anemones get too close to another, their tentacles will become club-like and swollen with stinging cells to ward off other anemones competing for space.
Adaptation
If conditions are not ideal or they are being harassed by predators, sea anemones can move to a new spot using their foot. In addition, they can retract their tentacles during low tide, to prevent dessication (drying out).
Sea anemones also have receptors in their tentacles to detect a pheromone called anthopleurin, which is produced by wounded anemones. When the pheromone is detected, the anemone will be alarmed and retract its tentacles to keep it safe from predators.
Anemones have venom in their rings of tentacles which can paralyze prey or defend against attackers.
Longevity
Little information has been recorded on the lifespan of the green sea anemone. However, there is a record for a green sea anemone living 80 years under human care, and scientists estimate that the green sea anemone can live up to at most 150 years. Fish-eating sea anemones live sixty to eighty years on average.
Conservation
IUCN has not yet released a conservation status for the green sea anemone.
Special Notes
The mouth functions to both take in food and expel waste—it’s the entrance and the exit!
Green Sea Anemones give hermit crabs homes by ejecting empty shells (their waste products) that the crabs can live in.
The venom in their nematocysts (small stinging cells) is useful for pharmaceutical drugs, such as heart stimulants.
SPECIES IN DETAIL | Print full entry
Green Sea Anemone
Anthopleura xanthogrammica
CONSERVATION STATUS: Data deficient
CLIMATE CHANGE: Uncertain
Northern Pacific Gallery
Green sea anemones are found primarily along the west coast of North and Central America. They are also found in Hudson Bay, Canada and the eastern coast of Russia.
Usually found in tide pools, Green sea anemones attach to rocks, coral, or man-made structures (like concrete). They thrive in cold waters of about 15.0-22.2 celsius (59.0-72.0 degrees fahrenheit). These creatures are about 0-5m (0-15 feet) in the water.
Green sea anemones have tube-like body structures, with at least six rings of tentacles surrounding the mouth. The column diameter can be up to 17 cm and they can grow up to 30 cm tall. They have a basal pedal disk that allows them to attach themselves to the substrate. The column ranges in color from dark green to brown with irregular tubercles on the surface.The disk and tentacles are green, blue or white depending on the amount of sunlight they receive. With more exposure to sunlight, their green coloration intensifies.
Height: Can grow up to 30 centimeters (12 in) high Width:17 centimeters (7 in) in column diameter
The Green sea anemone diet consists of detached mussels, small fish, crabs, and sea urchins. They paralyze their prey with the nematocysts (small venomous stinging cells) on their tentacles, and use their tentacles to bring the food directly into the mouth. Once the food is digested, the waste products are expelled out of the mouth. Any shells from their diet are ejected and used as shelter such as the blue band hermit crabs. At the Aquarium of the Pacific, we feed the green sea anemones small cut up fish, crabs, and shrimp.
Spawning green sea anemones usually happen in warmer waters so breeding seasons are during the late summer and early fall. Reproduction occurs through external fertilization. Females will release thousands of eggs, while males will release sperm into the water column. The resulting planktonic larvae will then drift and eventually settle on the seafloor. Green sea anemones reach sexual maturity at five to ten years old. There can be anywhere from 3,000-9,000 offspring.They are broadcast spawners since there is no parental involvement past that production of gametes stage.
Green sea anemones move very little in their lifetime and prefer to live in solitude, however, they are commonly found in small groups of up to fourteen individuals. There is usually an empty space between adjacent colonies of anemones. If anemones get too close to another, their tentacles will become club-like and swollen with stinging cells to ward off other anemones competing for space.
If conditions are not ideal or they are being harassed by predators, sea anemones can move to a new spot using their foot. In addition, they can retract their tentacles during low tide, to prevent dessication (drying out).
Sea anemones also have receptors in their tentacles to detect a pheromone called anthopleurin, which is produced by wounded anemones. When the pheromone is detected, the anemone will be alarmed and retract its tentacles to keep it safe from predators.
Anemones have venom in their rings of tentacles which can paralyze prey or defend against attackers.
Little information has been recorded on the lifespan of the green sea anemone. However, there is a record for a green sea anemone living 80 years under human care, and scientists estimate that the green sea anemone can live up to at most 150 years. Fish-eating sea anemones live sixty to eighty years on average.
IUCN has not yet released a conservation status for the green sea anemone.
The mouth functions to both take in food and expel waste—it’s the entrance and the exit!
Green Sea Anemones give hermit crabs homes by ejecting empty shells (their waste products) that the crabs can live in.
The venom in their nematocysts (small stinging cells) is useful for pharmaceutical drugs, such as heart stimulants.