Pom-Pom Anemones | Oceana Canada

Canadian Marine Life Encyclopedia

Pom-Pom Anemones

Liponema brevicornis

Also known as

Tentacle shedding anemone

Distribution

Deep waters in the north east Pacific Ocean

Ecosystem/Habitat

Sandy, muddy, and gravel bottoms

Feeding Habits

Predator and scavenger

Conservation Status

Not listed

Taxonomy

Class Anthozoa (corals, anemones & relatives), Order Actiniaria (true sea anemones)

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Although most people associate pom-pom anemones to the likes of a pretty flower or puffy purple troll hair, this species’ appearance can range from fluffy to flat. They can either be fixed to a substrate – ranging from soft sands to hard rocks, and even whale skeletons – or unlike other anemones, unattached and tumbling across the seafloor propelled by the ocean currents. They are a deep-water species most commonly found in the north east Pacific Ocean, at depths from 100 to 1000 metres but have been recorded at depths of over 3000 metres! Pom-pom anemones are also known to occur near hydrothermal vents, cold seeps and whale falls. 

While on expedition in the Central Coast of British Columbia, we spotted a wall of pom-pom anemones at almost 400 metres deep!

Pom-pom anemones range from 25-30 centimetres in diameter at maturity. They have an oral disc covered in stinging tentacles, which they use to capture food such as plankton, small crustaceans and krill. At the base of each tentacle is a sphincter muscle which can be contracted to shed the tentacle if necessary, mostly in instances of escaping predators – hence their nickname “tentacle-shedding anemone”. They have been spotted in many different shapes and sizes, from full and fluffy to low and deflated and are typically light pinkish-purple in colour.

Like much about pom-pom anemones, little is known about their life cycle. Some members of the same class can have one or both distinct sex organs, and research suggests they likely only reproduce sexually. Both the eggs and sperm are shed into their gastric cavity and spawned through their mouths. The fertilized eggs then develop into a planktonic larva, which is free-swimming in the water column. The first stages of development from the larva to a mature anemone begins with forming the tentacles and then settling onto the seafloor with the mouth pointing upwards. Pom-pom anemones may begin their lives as free-swimming larvae, but as adults are considered polyps and with no medusa stage being observed.

There are no fisheries that directly target pom-pom anemones. However, they can be caught as bycatch in bottom contact fishing methods such as bottom trawling or dredging. Anemones and corals provide essential habitats for many different marine species. The destruction of this habitat can reduce the productivity of fisheries, as fish and invertebrate populations that rely on these habitats for refuge, nurseries and food decline.

Pom-pom anemones have not been assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), nor have they been listed under the Species at Risk Act (SARA). There is still much to learn about pom-pom anemones; however, they likely face threats from human activity such as pollution, habitat destruction and destructive fishing practices.

Encyclopedia of Life. (n.d.). Liponema brevicornis, Tentacle Shedding Anemone. Retrieved from http://www.eol.org/pages/421494/overview#cite_note-MBA-3 

World Register of Marine Species. (n.d.). Liponema brevicornis (McMurrich, 1893). Retrieved from http://www.marinespecies.org/aphia.php?p=taxdetails&id=283700 

Monterey Bay Aquarium. (2018). Pom-pom anemone. Retrieved from https://www.montereybayaquarium.org/animal-guide/invertebrates/pom-pom-anemone 

Eash-Loucks W., and D. Fautin. (2012). Taxonomy and distribution of sea anemones (Cnidaria: Actinaria and Corallimorpharia) from deep water of the northeastern Pacific. Retrieved from https://kuscholarworks.ku.edu/bitstream/handle/1808/13640/Fautin_2012.pdf 

Vrijenhoek, R. (2010). Sea spiders and pom-pom anemones. Retrieved from https://www.mbari.org/sea-spiders-and-pom-pom-anemones/ 

Sea Life Base. (n.d.). Liponema brevicornis. http://www.sealifebase.org/summary/Liponema-brevicornis.html