Ivell's sea anemone (Edwardsia ivelli)

Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help

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

<1

Identifying 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 entered

Biology review

Taxonomy

LevelScientific nameCommon name
PhylumCnidaria
ClassAnthozoa
OrderActiniaria
FamilyEdwardsiidae
GenusEdwardsia
AuthorityManuel, 1975
Recent Synonyms

Biology

ParameterData
Typical abundanceData deficient
Male size range20mm
Male size at maturity
Female size rangeSmall(1-2cm)
Female size at maturity
Growth form
Growth rateNo information found
Body flexibility
Mobility
Characteristic feeding methodNo information, Predator
Diet/food sourceNo information
Typically feeds on
Sociability
Environmental positionInfaunal
DependencyNo information found.
SupportsNo information found
Is the species harmful?No information

Biology information

-none-

Habitat preferences

ParameterData
Physiographic preferencesIsolated saline water (Lagoon)
Biological zone preferencesNot relevant
Substratum / habitat preferencesMud
Tidal strength preferencesVery weak (negligible)
Wave exposure preferencesNot relevant
Salinity preferencesData deficient
Depth range<1
Other preferencesNo text entered
Migration PatternNon-migratory or 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

ParameterData
Reproductive typeNo information
Reproductive frequency No information
Fecundity (number of eggs)No information
Generation timeInsufficient information
Age at maturityInsufficient information
SeasonInsufficient information
Life spanInsufficient information

Larval characteristics

ParameterData
Larval/propagule type-
Larval/juvenile development No information
Duration of larval stageNo information
Larval dispersal potential No information
Larval settlement periodInsufficient information

Life history information

No text entered

Sensitivity reviewHow is sensitivity assessed?

Physical pressures

Use / to open/close text displayed

 IntoleranceRecoverabilitySensitivityEvidence / Confidence
Substratum loss [Show more]

Substratum loss

Benchmark. All of the substratum occupied by the species or biotope under consideration is removed. A single event is assumed for sensitivity assessment. Once the activity or event has stopped (or between regular events) suitable substratum remains or is deposited. Species or community recovery assumes that the substratum within the habitat preferences of the original species or community is present. Further details

Evidence

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.

High No information High Low
Smothering [Show more]

Smothering

Benchmark. All of the population of a species or an area of a biotope is smothered by sediment to a depth of 5 cm above the substratum for one month. Impermeable materials, such as concrete, oil, or tar, are likely to have a greater effect. Further details.

Evidence

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.

Intermediate No information High Low
Increase in suspended sediment [Show more]

Increase in suspended sediment

Benchmark. An arbitrary short-term, acute change in background suspended sediment concentration e.g., a change of 100 mg/l for one month. The resultant light attenuation effects are addressed under turbidity, and the effects of rapid settling out of suspended sediment are addressed under smothering. Further details

Evidence

The species inhabits isolated saline lagoons and typically burrows in mud and so siltation is unlikely to be a problem for the feeding mechanism.

Low No information Moderate Low
Decrease in suspended sediment [Show more]

Decrease in suspended sediment

Benchmark. An arbitrary short-term, acute change in background suspended sediment concentration e.g., a change of 100 mg/l for one month. The resultant light attenuation effects are addressed under turbidity, and the effects of rapid settling out of suspended sediment are addressed under smothering. Further details

Evidence

No information
Desiccation [Show more]

Desiccation

  1. A normally subtidal, demersal or pelagic species including intertidal migratory or under-boulder species is continuously exposed to air and sunshine for one hour.
  2. A normally intertidal species or community is exposed to a change in desiccation equivalent to a change in position of one vertical biological zone on the shore, e.g., from upper eulittoral to the mid eulittoral or from sublittoral fringe to lower eulittoral for a period of one year. Further details.

Evidence

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
Increase in emergence regime [Show more]

Increase in emergence regime

Benchmark. A one hour change in the time covered or not covered by the sea for a period of one year. Further details

Evidence

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.

High No information High Low
Decrease in emergence regime [Show more]

Decrease in emergence regime

Benchmark. A one hour change in the time covered or not covered by the sea for a period of one year. Further details

Evidence

No information
Increase in water flow rate [Show more]

Increase in water flow rate

A change of two categories in water flow rate (view glossary) for 1 year, for example, from moderately strong (1-3 knots) to very weak (negligible). Further details

Evidence

The species is only found in lagoons with negligible water flow. If the water flow regime were to change then the population would die.

High No information High Low
Decrease in water flow rate [Show more]

Decrease in water flow rate

A change of two categories in water flow rate (view glossary) for 1 year, for example, from moderately strong (1-3 knots) to very weak (negligible). Further details

Evidence

No information
Increase in temperature [Show more]

Increase in temperature

  1. A short-term, acute change in temperature; e.g., a 5°C change in the temperature range for three consecutive days. This definition includes ‘short-term’ thermal discharges.
  2. A long-term, chronic change in temperature; e.g. a 2°C change in the temperature range for a year. This definition includes ‘long term’ thermal discharges.

For intertidal species or communities, the range of temperatures includes the air temperature regime for that species or community. Further details

Evidence

Living in a eurythermal environment the species is probably tolerant to quite wide temperature changes outside its usual range.

Low No information Moderate Very low
Decrease in temperature [Show more]

Decrease in temperature

  1. A short-term, acute change in temperature; e.g., a 5°C change in the temperature range for three consecutive days. This definition includes ‘short-term’ thermal discharges.
  2. A long-term, chronic change in temperature; e.g. a 2°C change in the temperature range for a year. This definition includes ‘long term’ thermal discharges.

For intertidal species or communities, the range of temperatures includes the air temperature regime for that species or community. Further details

Evidence

No information
Increase in turbidity [Show more]

Increase in turbidity

  1. A short-term, acute change; e.g., two categories of the water clarity scale (see glossary) for one month, such as from medium to extreme turbidity.
  2. A long-term, chronic change; e.g., one category of the water clarity scale (see glossary) for one year, such as from low to medium turbidity. Further details

Evidence

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.

Tolerant Not relevant Not sensitive Low
Decrease in turbidity [Show more]

Decrease in turbidity

  1. A short-term, acute change; e.g., two categories of the water clarity scale (see glossary) for one month, such as from medium to extreme turbidity.
  2. A long-term, chronic change; e.g., one category of the water clarity scale (see glossary) for one year, such as from low to medium turbidity. Further details

Evidence

No information
Increase in wave exposure [Show more]

Increase in wave exposure

A change of two ranks on the wave exposure scale (view glossary) e.g., from Exposed to Extremely exposed for a period of one year. Further details

Evidence

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.

High No information High Low
Decrease in wave exposure [Show more]

Decrease in wave exposure

A change of two ranks on the wave exposure scale (view glossary) e.g., from Exposed to Extremely exposed for a period of one year. Further details

Evidence

No information
Noise [Show more]

Noise

  1. Underwater noise levels e.g., the regular passing of a 30-metre trawler at 100 metres or a working cutter-suction transfer dredge at 100 metres for one month during important feeding or breeding periods.
  2. Atmospheric noise levels e.g., the regular passing of a Boeing 737 passenger jet 300 metres overhead for one month during important feeding or breeding periods. Further details

Evidence

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
Visual presence [Show more]

Visual presence

Benchmark. The continuous presence for one month of moving objects not naturally found in the marine environment (e.g., boats, machinery, and humans) within the visual envelope of the species or community under consideration. Further details

Evidence

The species has no visual ability.

Tolerant Not relevant Not sensitive Very low
Abrasion & physical disturbance [Show more]

Abrasion & physical disturbance

Benchmark. Force equivalent to a standard scallop dredge landing on or being dragged across the organism. A single event is assumed for assessment. This factor includes mechanical interference, crushing, physical blows against, or rubbing and erosion of the organism or habitat of interest. Where trampling is relevant, the evidence and trampling intensity will be reported in the rationale. Further details.

Evidence

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.

High No information High Low
Displacement [Show more]

Displacement

Benchmark. Removal of the organism from the substratum and displacement from its original position onto a suitable substratum. A single event is assumed for assessment. Further details

Evidence

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.

Tolerant Not relevant Not sensitive Very low

Chemical pressures

Use [show more] / [show less] to open/close text displayed

 IntoleranceRecoverabilitySensitivityEvidence / Confidence
Synthetic compound contamination [Show more]

Synthetic compound contamination

Sensitivity is assessed against the available evidence for the effects of contaminants on the species (or closely related species at low confidence) or community of interest. For example:

  • evidence of mass mortality of a population of the species or community of interest (either short or long term) in response to a contaminant will be ranked as high sensitivity;
  • evidence of reduced abundance, or extent of a population of the species or community of interest (either short or long term) in response to a contaminant will be ranked as intermediate sensitivity;
  • evidence of sub-lethal effects or reduced reproductive potential of a population of the species or community of interest will be assessed as low sensitivity.

The evidence used is stated in the rationale. Where the assessment can be based on a known activity then this is stated. The tolerance to contaminants of species of interest will be included in the rationale when available; together with relevant supporting material. Further details.

Evidence

Insufficient
information

No information No information No information Not relevant
Heavy metal contamination [Show more]

Heavy metal contamination

Evidence

Insufficient
information

No information No information No information Not relevant
Hydrocarbon contamination [Show more]

Hydrocarbon contamination

Evidence

Insufficient
information

No information No information No information Not relevant
Radionuclide contamination [Show more]

Radionuclide contamination

Evidence

Insufficient
information

No information No information No information Not relevant
Changes in nutrient levels [Show more]

Changes in nutrient levels

Evidence

Direct changes in nutrient levels to this species are unknown, but increased levels of dissolved nutrients may stimulate algal over-growth.

No information No information No information Not relevant
Increase in salinity [Show more]

Increase in salinity

  1. A short-term, acute change; e.g., a change of two categories from the MNCR salinity scale for one week (view glossary) such as from full to reduced.
  2. A long-term, chronic change; e.g., a change of one category from the MNCR salinity scale for one year (view glossary) such as from reduced to low. Further details.

Evidence

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.

Low No information Moderate Very low
Decrease in salinity [Show more]

Decrease in salinity

  1. A short-term, acute change; e.g., a change of two categories from the MNCR salinity scale for one week (view glossary) such as from full to reduced.
  2. A long-term, chronic change; e.g., a change of one category from the MNCR salinity scale for one year (view glossary) such as from reduced to low. Further details.

Evidence

No information
Changes in oxygenation [Show more]

Changes in oxygenation

Benchmark.  Exposure to a dissolved oxygen concentration of 2 mg/l for one week. Further details.

Evidence

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.

Low No information Moderate Very low

Biological pressures

Use [show more] / [show less] to open/close text displayed

 IntoleranceRecoverabilitySensitivityEvidence / Confidence
Introduction of microbial pathogens/parasites [Show more]

Introduction of microbial pathogens/parasites

Benchmark. Sensitivity can only be assessed relative to a known, named disease, likely to cause partial loss of a species population or community. Further details.

Evidence

Insufficient
information

No information No information No information Not relevant
Introduction of non-native species [Show more]

Introduction of non-native species

Sensitivity assessed against the likely effect of the introduction of alien or non-native species in Britain or Ireland. Further details.

Evidence

Insufficient
information

No information No information No information Not relevant
Extraction of this species [Show more]

Extraction of this species

Benchmark. Extraction removes 50% of the species or community from the area under consideration. Sensitivity will be assessed as 'intermediate'. The habitat remains intact or recovers rapidly. Any effects of the extraction process on the habitat itself are addressed under other factors, e.g. displacement, abrasion and physical disturbance, and substratum loss. Further details.

Evidence

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
Extraction of other species [Show more]

Extraction of other species

Benchmark. A species that is a required host or prey for the species under consideration (and assuming that no alternative host exists) or a keystone species in a biotope is removed. Any effects of the extraction process on the habitat itself are addressed under other factors, e.g. displacement, abrasion and physical disturbance, and substratum loss. Further details.

Evidence

The anemone has no known obligate relationships.

Not relevant No information Not relevant Very low

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

DesignationSupport
Wildlife & Countryside ActSchedule 5, section 9
UK Biodiversity Action Plan PriorityYes
Species of principal importance (England)Yes

Status

Non-native

ParameterData
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

  1. 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.

  2. 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.]

  3. 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.

  4. 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

  5. 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

  1. NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.

  2. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2024-05-23

  3. 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 23-05-2024]. Available from: https://marlin.ac.uk/species/detail/1140

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Last Updated: 13/07/1999