Ivell's sea anemone (Edwardsia ivelli)
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| Researched by | Angus Jackson | Refereed by | Dr Simon K. Davy |
| Authority | Manuel, 1975 | ||
| Other common names | - | Synonyms | - |
Summary
Description
A very small translucent sea anemone. The disc is buff coloured with orange spots. The tentacles are transparent, spotted with brown and cream.
Recorded distribution in Britain and Ireland
Widewater lagoon, West Sussex.Global distribution
Widewater lagoon, West Sussex, England.Habitat
Lives in long burrows in deep, soft lagoon mud.Depth range
<1Identifying features
- A very small species, up to 2 cm long and 1.25 mm diameter when fully extended.
- Nemathybomes visible as small tubercles arranged in 8 longitudinal rows.
- Periderm thin and translucent.
- Tentacles 12, arranged in two cycles, 3 + 9.
- Physa without cinclides.
Additional information
No text enteredListed by
Biology review
Taxonomy
| Phylum | Cnidaria | Sea anemones, corals, sea firs & jellyfish |
| Class | Anthozoa | Sea anemones, soft & cup corals, sea pens & sea pansies |
| Order | Actiniaria | |
| Family | Edwardsiidae | |
| Genus | Edwardsia | |
| Authority | Manuel, 1975 | |
| Recent Synonyms | ||
Biology
| Typical abundance | Data deficient | ||
| Male size range | 20mm | ||
| Male size at maturity | |||
| Female size range | Small(1-2cm) | ||
| Female size at maturity | |||
| Growth form | |||
| Growth rate | No information found | ||
| Body flexibility | |||
| Mobility | |||
| Characteristic feeding method | No information, Predator | ||
| Diet/food source | No information | ||
| Typically feeds on | |||
| Sociability | |||
| Environmental position | Infaunal | ||
| Dependency | No information found. | ||
| Supports | No information found | ||
| Is the species harmful? | No information | ||
Biology information
-none-Habitat preferences
| Physiographic preferences | Isolated saline water (Lagoon) |
| Biological zone preferences | Not relevant |
| Substratum / habitat preferences | Mud |
| Tidal strength preferences | Very Weak (negligible) |
| Wave exposure preferences | Not relevant |
| Salinity preferences | Data deficient |
| Depth range | <1 |
| Other preferences | No text entered |
| Migration Pattern | Non-migratory / resident |
Habitat Information
This species has not been recorded since 1983. Three surveys have since failed to record this species. It may be that it exists in such low numbers that rediscovery in surveys is unlikely. Additionally, the conditions in the lagoon have varied considerably over the last 20 years. Water levels have fallen as a result of little seawater input, the remaining water is hypersaline. Areas of the lagoon basin have become exposed, subsequently changes in the lagoon community have been recorded. It has been suggested that this species may now be extinct.Life history
Adult characteristics
| Reproductive type | No information | |
| Reproductive frequency | No information | |
| Fecundity (number of eggs) | No information | |
| Generation time | Insufficient information | |
| Age at maturity | Insufficient information | |
| Season | Insufficient information | |
| Life span | Insufficient information |
Larval characteristics
| Larval/propagule type | - |
| Larval/juvenile development | No information |
| Duration of larval stage | No information |
| Larval dispersal potential | No information |
| Larval settlement period | Insufficient information |
Life history information
No text enteredSensitivity review
The MarLIN sensitivity assessment approach used below has been superseded by the MarESA (Marine Evidence-based Sensitivity Assessment) approach (see menu). The MarLIN approach was used for assessments from 1999-2010. The MarESA approach reflects the recent conservation imperatives and terminology and is used for sensitivity assessments from 2014 onwards.
Physical pressures
| Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
| High | No information | High | Low | |
| The species typically lives within the mud substratum, removal of this would cause the anemone to die. No information is available regarding the reproduction of this species. | ||||
| Intermediate | No information | High | Low | |
| The species typically burrows in mud so some individuals would probably be able to move up through the smothering material. However, it is very small and might be damaged by the smothering material. No information is available regarding the reproduction of this species. | ||||
| Low | No information | Moderate | Low | |
| The species inhabits isolated saline lagoons and typically burrows in mud and so siltation is unlikely to be a problem for the feeding mechanism. | ||||
| No information | ||||
| High | No information | High | Low | |
| The species is found below water level and exposure of the species to desiccating influences through drying of the pools or lagoons would cause the population to die. No information is available regarding the reproduction of this species. | ||||
| High | No information | High | Low | |
| The species is found below water level in isolated saline lagoons where there is no tidal regime. If there was modification of the lagoon system creating a tidal influence, causing the population to be emersed then it would die. No information is available regarding the reproduction and therefore recoverability potential of this species. | ||||
| No information | ||||
| High | No information | High | Low | |
| The species is only found in lagoons with negligible water flow. If the water flow regime were to change then the population would die. | ||||
| No information | ||||
| Low | No information | Moderate | Very low | |
| Living in a eurythermal environment the species is probably tolerant to quite wide temperature changes outside its usual range. | ||||
| No information | ||||
| Tolerant | Not relevant | Not sensitive | Low | |
| The species inhabits shallow isolated lagoons which are subjected to both sea and freshwater inputs, where there is often high levels of near-bottom turbidity. This turbidity is unlikely to affect a non-photosynthetic species, unless it is extreme enough to cause smothering. | ||||
| No information | ||||
| High | No information | High | Low | |
| Typical habitat of isolated lagoons is not exposed to wave action. Although losses in fine substratum may be problematic in habitat stability. Any change in this would cause the population to die. No information is available regarding the reproduction of this species. | ||||
| No information | ||||
| Tolerant | Not relevant | Not sensitive | Very low | |
| The species is likely to show little response to noise vibrations, although other species of anemone are known to contract in response to vibration. | ||||
| Tolerant | Not relevant | Not sensitive | Very low | |
| The species has no visual ability. | ||||
| High | No information | High | Low | |
| This species is very small and has a very soft body. It would be easily damaged by abrasion or physical disturbance and intolerance is probably high. No information is available regarding the reproduction of this species. | ||||
| Tolerant | Not relevant | Not sensitive | Very low | |
| This is a burrowing species that would probably be able to re-establish itself in the sediment if displaced. The quite similar Nematostella vectensis is capable of moving from sediment up on to an algal substratum and back again. | ||||
Chemical pressures
| Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
| No information | No information | No information | Not relevant | |
| Insufficient information | ||||
| No information | No information | No information | Not relevant | |
| Insufficient information | ||||
| No information | No information | No information | Not relevant | |
| Insufficient information | ||||
| No information | No information | No information | Not relevant | |
| Insufficient information | ||||
| No information | No information | No information | Not relevant | |
| Direct changes in nutrient levels to this species are unknown, but increased levels of dissolved nutrients may stimulate algal over-growth. | ||||
| Low | No information | Moderate | Very low | |
| The species inhabits shallow, eurythermal lagoons that probably have wide fluctuations in salinity and so is probably quite tolerant to varying levels of salinity. Extrapolation from Nematostella vectensis. | ||||
| No information | ||||
| Low | No information | Moderate | Very low | |
| The species inhabits shallow, eurythermal lagoons that probably have wide fluctuations in dissolved oxygen concentration and so is probably quite tolerant to low levels of oxygen. Extrapolation from Nematostella vectensis. | ||||
Biological pressures
| Intolerance | Recoverability | Sensitivity | Evidence/Confidence | |
| No information | No information | No information | Not relevant | |
| Insufficient information | ||||
| No information | No information | No information | Not relevant | |
| Insufficient information | ||||
| Not relevant | No information | Not relevant | Very low | |
| No reason for extraction. The species, if still extant is protected by a UK Biodiversity Action Plan and by the Wildlife and Countryside Act (1981). | ||||
| Not relevant | No information | Not relevant | Very low | |
| The anemone has no known obligate relationships. | ||||
Additional information
All the above intolerance assessments are made on the assumption that the species is still extant. The species inhabits a very restricted range of conditions and most changes to these will cause the population to die. %Nematostella vectensis% has been used as a model for inferring many of the intolerance ranks. No information is available regarding the reproduction of this species so no assessment of recoverability is possible.Importance review
Policy/legislation
| Wildlife & Countryside Act | Schedule 5, section 9 |
| UK Biodiversity Action Plan Priority | |
| Species of principal importance (England) |
Status
| National (GB) importance | Not rare/scarce | Global red list (IUCN) category | - |
Non-native
| Native | - | ||
| Origin | - | Date Arrived | - |
Importance information
Possibly extinct.Further surveys in lagoon habitat are required to establish whether it continues to survive either in Widewater lagoon or elsewhere.
Bibliography
Anonymous, 1999d. Ivell's sea anemone, (Edwardsia ivelli). Species Action Plan. In UK Biodiversity Group. Tranche 2 Action Plans. English Nature for the UK Biodiversity Group, Peterborough., English Nature for the UK Biodiversity Group, Peterborough.
Howson, C.M. & Picton, B.E., 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas. Belfast: Ulster Museum. [Ulster Museum publication, no. 276.]
Manuel, R.L., 1975. A new sea anemone from a brackish lagoon in Sussex, Edwardsia ivelli, sp. Nov. Journal of Natural History, 9, 705-711.
Manuel, R.L., 1988. British Anthozoa. Synopses of the British Fauna (New Series) (ed. D.M. Kermack & R.S.K. Barnes). The Linnean Society of London [Synopses of the British Fauna No. 18.]. DOI https://doi.org/10.1002/iroh.19810660505
Sheader, M. & Sheader, A., 1990. A survey of Widewater saline lagoon to determine the current status of the site, with special reference to Ivell's sea anemone, Edwardsia ivelli. Preliminary Report, Peterborough. Nature Conservancy Council. NCC CSD Report 1176.
Datasets
NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.
OBIS (Ocean Biodiversity Information System), 2023. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2023-03-30
Suffolk Biodiversity Information Service., 2017. Suffolk Biodiversity Information Service (SBIS) Dataset. Occurrence dataset: https://doi.org/10.15468/ab4vwo accessed via GBIF.org on 2018-10-02.
Citation
This review can be cited as:
Jackson, A. 1999. Edwardsia ivelli Ivell's sea anemone. In Tyler-Walters H. and Hiscock K. Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 30-03-2023]. Available from: https://www.marlin.ac.uk/species/detail/1140
Last Updated: 13/07/1999
