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Species

Jewel anemone

Jewel anemone Corynactis viridis

Species description

The Jewel anemone (Corynactis viridis) is a smooth anemone which can come in a plethora of colours such as green, white, orange, red and others1-4. These colours cause the anemone to look like a lot like a coral polyp except the anemone lacks a limestone skeleton in comparison to its hard coral relative1. The organisms found in the Netherlands thus far have only sported three different colour combinations: pure translucent white, translucent white with a yellow ring around the oral disk and translucent white with a pink ring around the oral disk5. Most Jewel anemone grow to a size of about 10mm in both height and width with up to a hundred small tentacles separated in to three wreaths with each tentacle ending in a small circular knob3 4.

Habitat and distribution

Jewel anemones are found in shallow waters up to a depth of 80m but most colonies are situated at around a depth of 50m. At these depths Jewel anemones prefer to settle in places with hard substrates and very little to no light such as caves and overhangs where multiple individuals can be found as a dense population2-4 6. Jewel anemones also have a preferences for turbulent water causing them to appear in areas with strong currents1 7.


Jewel anemones have been known to be distributed across the south and west coast of Britain and Europe, The Mediterranean and around Ireland and parts of Scotland2-4 7. But only in 2013 were they first spotted in Dutch waters during an expedition to the Bruine Bank thus confirming that they have settled in the North sea8. It is speculated that this might be related to the rising of the temperature of the North sea due to global warming as it is uncommon for a typically southern species like the Jewel anemone to spread its range6 9. Another theory however is that this expansion is most likely caused by a variety of circumstances such as sedimentation and current changes9.

Food and predators

The Jewel anemone primarily feeds on small fish, shrimp and other forms of small invertebrates which they catch and paralyze using the nematocyst in their tentacles1 3 7. The Jewel anemone itself however does not appear to be preyed on as none of the found sources mentioned any predators. This could however could also be caused due to a lack of in-depth research.

Reproduction

Jewel anemone have primarily been found reproducing asexually by splitting themselves longitudinally. This process when repeated often results in the creation of the previously mentioned dense colonies of Jewel anemone1 3 6 7. Due to the species being relatively new to the North sea, a lack of reliable data and the fact that it reproduces asexually, it is currently unknown how suitable the Jewel anemone is for artificial cultivation and assisted reproduction.6

Status and protection

At the moment the IUCN has labelled the Jewel anemone as ‘Least concern’, it should however be noted that this analysis is based on an assessment taken in the Mediterranean and may vary from their current state in the North sea9.

As previously mentioned, the Jewel anemone has appeared to have settled only recently in the North sea5. And even after their discovery very little is known about the possibilities of artificial growth for these anemones6. Making efforts to increase the number of Jewel anemone colonies could in return give more opportunities to learn more about this species.

Literature

1 WNF. (sd). juweelanemoon. http://www.natuurinformatie.nl/ndb.wnf/natuurdatabase.nl/i000868.html

2 de Kluijver, M. J., & Ingalsuo, S. S. (sd). Jewel anemone - Corynactis viridis.: http://species-identification.org/species.php?species_group=anthozoa&menuentry=soorten&id=99&tab=beschrijving

3 The Wildlife Trusts (sd). Jewel anemone.

https://www.wildlifetrusts.org/wildlife-explorer/marine/anemones-and-corals/jewel-anemone

4 Ager, O. (sd). Jewel anemone (Corynactis viridis). https://www.marlin.ac.uk/species/detail/1567

5 Gittenberger, A., Schrieken, N., Coolen, J., & Vlierhuis, W. (2013). The juwel anemone corynactisviridis, a new order for the netherlands (cnidaria: corallimorpharia).

6 van Duren, L., Gittenberger, A., Smaal, A., van Koningsveld, M., Osinga, R., Cado van der Lelij, C., & de Vries, M. (2016). Rijke riffen in de Noordzee.

7 SCUBA Travel (sd) Jewel-anemone, Corynactis viridis. https://www.scubatravel.co.uk/marine-life/jewel-anemone.html

8 Stiefelhagen, B. (2013). Persbericht Expeditie Bruine Bank. Opgehaald van Duik de Noordzee schoon: https://www.duikdenoordzeeschoon.nl/persbericht-expeditie-bruine-bank/

9 Bo, M., Bavestrello, G., Garcia, S., Forero, A., Goffredo, S., Linares, C., & Ozalp, B. (2015). Corynactis viridis (Jewel Anemone). https://www.iucnredlist.org/species/50149031/50860520

Author: The Rich North Sea

Year: 2021