Lagoon snail (Paludinella globularis)

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

Summary

Description

A small, globose snail that grows up to 2 mm high. The shell is glossy and semitransparent. The animal is pale grey and appears whitish through the shell. The tentacles are short and stubby with eyes seen as two black dots. It is often easily confused with juvenile Littorina saxatilis.

Recorded distribution in Britain and Ireland

Recorded from the Isle of Wight, the Fleet, North Devon, South Devon, Pembrokeshire, Cornwall and Isles of Scilly.

Global distribution

Primarily a Mediterranean species (absent from the Black Sea) which extends along Eastern Atlantic coasts from Madeira north to a limit on the south coast of England.

Habitat

Occurs in crevices, caves, under rocks and in lagoonal shingle, at or just above the water line. The caves are usually sheltered and the surface of the walls colonized by green and red algal films and soft crusts. Sites in caves are associated with lithologies which are foliated and fissile allowing the development of fissures and crevices.

Depth range

Not relevant

Identifying features

  • Tiny globose tarn-coloured shell.
  • Broad bifid snout.
  • Tentacles broad, joined and rounded, with a black eye in the centre of each left and right lobe.

Additional information

The pulmonate Otina ovata is a frequent associate of Paludinella globularis, in caves etc. In shingle, it often occurs with the pulmonates Ovatella myosotis and (slightly lower on the shore) Leucophytia bidentata, and the prosobranch Truncatella subcylindrica.

Kadolsky (2012) showed that the original description of type species of Paludinella littorina (originally described as Helix littorina Delle Chiaje, 1828), was most probably based on small specimens of Melarhaphe neritoides (Linnaeus, 1758). The original type description was, therefore, incorrect. In addition, Pfeiffer (1841) based the genus Paludinella on the taxonomic extension given to that name by Philippi (1841), i.e. a misidentified type species. Furthermore, Kadolsky noted that the correct name for specimens of P. littorina is, in fact, P. globularis.  Therefore, for specimens of Paludinella littorina of authors, non Delle Chiaje, Kadolsky restored the name Paludinella globularis and designated the latter as type species of Paludinella (Kadolsky, 2012; Bouchet, 2012).

Biology review

Taxonomy

LevelScientific nameCommon name
PhylumMollusca
ClassGastropoda
OrderLittorinimorpha
FamilyAssimineidae
GenusPaludinella
Authority(Hanley in Thorpe, 1844)
Recent SynonymsRissoa littorea Jeffreys, 1856Paludinella littorina (Delle Chiaje, 1828) sensu Philippi, 1841Cingula globularis Hanley in Thorpe, 1844

Biology

ParameterData
Typical abundanceModerate density
Male size rangemax. 2cm
Male size at maturityNo information
Female size rangemax. 2cm
Female size at maturityNo information
Growth formGlobose
Growth rateNo information
Body flexibilityNone (less than 10 degrees)
MobilityCreeper
Characteristic feeding methodSub-surface deposit feeder, Surface deposit feeder
Diet/food sourceDetritivore
Typically feeds onNo information
SociabilityGregarious
Environmental positionEpifaunal, Interstitial
DependencyNo information found.
SupportsNo information
Is the species harmful?No information

Biology information

Very little data on biology found. The animal crawls by alternately extending the front and rear halves of the foot forward, producing a shuffling gait. The foot is short and rounded. It is found at low to moderate densities in narrow, linear habitats.

Habitat preferences

ParameterData
Physiographic preferencesIsolated saline water (Lagoon), Open coast
Biological zone preferencesLower littoral fringe, Supralittoral, Upper littoral fringe
Substratum / habitat preferencesBedrock, Caves, Crevices / fissures, Gravel / shingle, Under boulders
Tidal strength preferencesVery weak (negligible), Weak < 1 knot (<0.5 m/sec.)
Wave exposure preferencesSheltered
Salinity preferencesVariable (18-40 psu)
Depth rangeNot relevant
Other preferencesNo information
Migration Pattern

Habitat Information

Paludinella globularis is probably under-recorded due to its small size, inaccessible habitat and the similarity of its shell to that of Littorina saxatilis. An update on the distribution of Paludinella globularis (as littorina) was compiled by Light & Killeen (2001). Frequent molluscan associates are the pulmonate Otina ovata in the crevice or cave habitat, and the pulmonates Ovatella myosotis and Leucophytia bidentata and prosobranch Truncatella subcylindrica in shingle interstices. Other species particularly associated with Paludinella gobularis are the Isopoda Ligia oceanica in cave habitats (unless Ligia oceanica is excessively dominant, then Paludinella globularis is excluded), and Bdella mites in the interstitial habitat of the upper shore shingle or boulders (Light & Killeen, 2001).

Life history

Adult characteristics

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

Larval characteristics

ParameterData
Larval/propagule typeNo information
Larval/juvenile development No information
Duration of larval stageNo information
Larval dispersal potential No information
Larval settlement periodNo information

Life history information

-none-

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

Paludinella globularis would be removed upon substratum loss. Light & Killeen (1997) suggest that cliff instability may be the main threat to those colonies. Recoverability would be low because populations of the species are sparse.

High Low High Very 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

Smothering could block shingle interstices, prevent movement of the snail and reduce the level of oxygenation. Recovery would be low because it probably lacks an aquatic dispersal phase and other colonies are distant.

High Low High Very 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 should be able to move through new silt and may be able to feed on it, so long as interstices remain clear.

Intermediate Moderate Moderate Very 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

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

Paludinella globularis is adapted to tolerate desiccation by its hard shell and operculum. However, the individuals that occur in crevices may not be able to tolerate twenty five percent increase in the time exposed to air. Those animals that are found in shingle will be largely sheltered from the effects of desiccation.

Intermediate Low High Very 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

Increased or decreased emergence is likely to occur on a relatively long time scale during which the habitat and animals will probably be able to re-adjust.

Low Moderate Low Very 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

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

Living at the high water mark, the species is inundated for only short periods so that increased water flow is unlikely to have a significant effect unless it is so great as to erode the substrate and wash animals away.

Low Moderate Low Very 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

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

The species reaches the northern limits of its distribution in England so may be particularly intolerant of reductions in temperature. The species would be protected from extremes in temperature where it lives in shingle or in crevices and caves.

Intermediate Moderate 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

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 will probably not be affected by a change in turbidity as it is not dependant on light availability.

Tolerant Not relevant Not sensitive Very 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

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

Increased wave action may damage or wash away this species or move shingle, damaging the animal by abrasion.

Intermediate Low High Very 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

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

No information.

No information Not relevant No information Not relevant
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

No information.

No information Not relevant No information Not relevant
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

Individuals living in caves and crevices are likely to be protected from physical disturbance. However, significantly increased pressure or trampling along high water mark at shingle sites could produce serious abrasion, which would damage the delicate shells.  Therefore, intolerance has been assessed as high.  Recovery would be low because populations are sparsely distributed.

High Very low / none Very 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

Habitat displacement would cause physical damage to animals.

High Low High 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

No information.

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

Heavy metal contamination

Evidence

No information.

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

Hydrocarbon contamination

Evidence

Observations following the Sea Empress oil spill off Pembrokeshire found that the populations of Paludinella globularis were not affected (Light & Killeen, 1997). However, prosobranchs usually are affected by hydrocarbons.

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

Radionuclide contamination

Evidence

No information.

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

Changes in nutrient levels

Evidence

No information.

No information Not relevant 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

Paludinella globularis can tolerate a wide range of salinities as evidenced by its distribution in lagoons and on open shore. The species may not be able to withstand low salinity for long periods of time.

Low Low Moderate High
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

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

No information.
No information Not relevant No information Not relevant

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

No information.

No information Not relevant 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

No information.

No information Not relevant 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

Not relevant.

Not relevant Not relevant Not relevant Not relevant
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

Could cause huge disturbance and damage but is unlikely.

High Low High Very low

Additional information

Importance review

Policy/legislation

DesignationSupport
IUCN Red ListLeast Concern (LC)

Status

Non-native

ParameterData
Native-
Origin-
Date Arrived-

Importance information

-none-

Bibliography

    Datasets

    1. Conchological Society of Great Britain & Ireland, 2018. Mollusc (marine) records for Great Britain and Ireland. Occurrence dataset: https://doi.org/10.15468/aurwcz accessed via GBIF.org on 2018-09-25.

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

    3. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2024-03-01

    Citation

    This review can be cited as:

    White, N. 2000. Paludinella globularis Lagoon snail. 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 01-03-2024]. Available from: https://www.marlin.ac.uk/species/detail/2282

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    Last Updated: 23/05/2000