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Hydrobiid Snail (Great Lake)


Beddomeia tumidaHydrobiid Snail (Great Lake)

Group:Mollusca (shellfish), Gastropoda (snails and slugs), Hypsogastropoda, Tateidae
Status:Threatened Species Protection Act 1995: endangered
Environment Protection and Biodiversity Conservation Act 1999: Not listed
Endemic in Tasmania and restricted
Click to enlarge
Beddomeia tumida is a tiny (3-4 mm) freshwater snail known to occur only in the Great Lake, in north-central Tasmania. The species has a very restricted range, recorded from only six areas across the lake. The principal threats to  B. tumida are associated with impoundment management, agricultural clearing and forestry. B. tumida may also be impacted by competition with and displacement by the exotic snail Potamopyrgus antipodarum (New Zealand hydrobiid). The principal management objectives for B. tumida include preventing the loss or degradation of habitat supporting known populations, and increasing public awareness of the species.

Key Points

  • Important: Is this species in your area? Do you need a permit? Ensure you’ve covered all the issues by checking the Planning Ahead page.
  • Important: Different threatened species may have different requirements. For any activity you are considering, read the Activity Advice pages for background information and important advice about managing around the needs of multiple threatened species.


  • 'Habitat’ refers to both known habitat for the species (i.e. in or near habitat where the species has been recorded) and potential habitat (i.e. areas of habitat with appropriate characteristics for the species and within the species' potential range which have not yet been adequately surveyed).
  • If in doubt about whether a site represents potential habitat for this species, contact the Threatened Species Section for further advice.
  • The known range of B. tumida includes six areas across the Great Lake (see distribution map, above). The potential range for B. tumida is the same as the known range as the species is unlikely to extend beyond Great Lake.
  • Habitat for B. tumida includes the following elements: submergent weedbeds and rocks on the lake bed.

What to avoid

  • Damage to the habitat through upstream agricultural, hydrological and forestry practices
  • Damage to stream habitat through altered flow regimes (e.g. due to land clearing, establishment of impoundments etc)



Key Survey reliability more info
M Peak survey period
M Potential survey period
M Non-survey period

To ensure you follow the law - check whether your survey requires a permit. Always report any new records to the Natural Values Atlas, or send the information direct to the Threatened Species Section. Refer to the Activity Advice: Surveying page for background information.

Species Spring Summer Autumn Winter
Beddomeia tumida S S O O N N D D J J F F M M A A M M J J J J A A


  • B. tumida is a very small, hard to find species which can be difficult to tell apart from other species of Beddomeia and the related genus Phrantela. Identification of Beddomeia to species level normally requires a specialist.
  • For further information on surveying or identifying this species, contact the Threatened Species Section.​​​​​

Helping the species


  • Important! Always report any observations of the species to the NRE Natural Values Atlas, or else provide the data direct to the Threatened Species Section. Records stored on the NVA are a permanent record and are accessible to other people interested in this species.
  • Consider the needs of the whole habitat. Preserving a threatened species' habitat is the best way to manage both the species and the environment in which it lives.
  • Cutting or clearing trees or vegetation

    • ​Activities which result in habitat degradation are the principal threats to B. tumida, including damage to weedbeds within the lake and clearing of lakeside vegetation.
    • To prevent direct damage to habitat – avoid damage to weedbeds in Great Lake.
    • To avoid indirect impacts on lake habitat – do not clear lakeside vegetation.










    Changing water flow / quality


    • Activities which result in habitat degradation are the principal threat to B. tumida, including alterations to lake water quality.
    • To avoid damage to lake habitat – manage activities within the lake catchment to minimise impact on lake water quality, including residential developments and waste-water treatment systems.​

    Use of chemicals


    • ​Activities which result in habitat degradation are the principal threat to B. tumida, including alterations to lake water quality.
    • To avoid damage to lake habitat – manage activities involving the use of chemicals within the lake catchment to avoid input of chemicals into the lake.



    Further information

    ​Check also for listing statement or notesheet pdf above (below the species image).

    ​​Cite as: Threatened Species Section (). (): Species Management Profile for Tasmania's Threatened Species Link. ​ ​Department of Natural Resources and Environment Tasmania. Accessed on .

    Contact details: Threatened Species Section, Department of Natural Resources and Environment Tasmania​, GPO Box 44, Hobart, Tasmania, Australia, 7001. Phone (1300 368 550).

    Permit: A permit is required under the Tasmanian Threatened Species Protection Act 1995 to 'take' (which includes kill, injure, catch, damage, destroy and collect), keep, trade in or process any specimen or products of a listed species. Additional permits may also be required under other Acts or regulations to take, disturb or interfere with any form of wildlife or its products, (e.g. dens, nests, bones). This may also depend on the tenure of the land and other agreements relating to its management. ​​​​​