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Ammonite Pinwheel Snail (Ammoniropa vigens)

The Ammonite Pinwheel Snail is a tiny land snail known from Tasmania, mainly in the Greater Hobart region, with a live record also reported outside Hobart. Wet forest remnants on dolerite, particularly those with mossy rocks, are important habitat to consider during works.

Conservation status

Commonwealth, EPBC Act 1999: Critically endangered.

Tasmania, Threatened Species Protection Act 1995: Endangered.

Seasonal planning

No species-specific activity or breeding months were found in the published sources used. Use the following as a works-planning prompt, not as seasonal biology.

Seasonal knowledge: Not documented in the sources used.

The month values are a general planning prompt only and do not represent known activity or breeding months for Ammoniropa vigens.

  • Plan checks before disturbance: General planning window only. Check the work area before disturbance whenever works are scheduled.

Identification: Appearance

This cryptic snail is about 3 mm wide. It can be difficult to locate because it occurs in small, localised clusters.

This cryptic snail is about 3 mm wide. It can be difficult to locate because it occurs in small, localised clusters.

Identification: Confirming identity

Confirm the identity of any suspected record with a specialist and a photograph or voucher, as required by the relevant permit.

Distribution: Known range

The species is endemic to Tasmania and is known mostly from a handful of sites in the Greater Hobart region. A juvenile live record has also been reported outside Hobart.

The species is endemic to Tasmania and is known mostly from a handful of sites in the Greater Hobart region. A juvenile live record has also been reported outside Hobart.

Distribution: National mapping

The Commonwealth species distribution model (SNES) maps where the species or its habitat is known, likely or may occur. Use it with local records and site inspection.

Habitat: Habitat

It occurs in forest remnants, often in dark, wet gullies and on steep slopes with dolerite rock. A dry site at Grass Tree Hill and a historic record from the Domain are noted exceptions.

It occurs in forest remnants, often in dark, wet gullies and on steep slopes with dolerite rock. A dry site at Grass Tree Hill and a historic record from the Domain are noted exceptions.

Foraging habitat: Diet

Not documented in the published sources used for this profile.

Not documented in the published sources used for this profile.

Breeding habitat: Breeding

Not documented in the published sources used for this profile.

Not documented in the published sources used for this profile.

Sheltering habitat: Shelter

The snail lives under mossy rocks in wet forests on dolerite rock.

The snail lives under mossy rocks in wet forests on dolerite rock.

Threats: Threats

Housing and urban development have reduced suitable habitat. In remaining areas, threats include predatory exotic molluscs, fire, land degradation and extreme weather.

Housing and urban development have reduced suitable habitat. In remaining areas, threats include predatory exotic molluscs, fire, land degradation and extreme weather.

Threats: Works risk

Land clearance and urban development can remove suitable habitat, while fire may affect remaining sites. Works near forest remnants should account for the risk of disturbance to these small, localised colonies.

Survey methodology: 1. Species-specific methods

Use methods consistent with the Commonwealth survey guidelines and engage a specialist with the right permits.

Surveys involve searching suitable forest and rocky habitats for snails. They can be time-consuming because the snails occur in small, localised clusters and may be absent from nearby suitable habitat.

Survey methodology: 2. Commonwealth guidance

For EPBC Act referrals, survey effort and methods should be consistent with the on-ground surveys and data for referred actions under the EPBC Act, read with the Significant impact guidelines 1.1.

Survey methodology: 3. Limits

A non-detection is not proof of absence. Match survey timing to the species and season, and record effort.

Vegetation associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific vegetation association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Ecosystem associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific ecosystem association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Soil and substrate associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific soil association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Water and wetland associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific water association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Fauna records and mapped habitat: Not yet analysed

Record locations can be overlaid with mapping, but record frequency alone does not measure habitat preference. No species is excluded from desktop assessments by this analysis.

No quality-controlled record-to-map analysis has been completed for this species. The existing generalised distribution dots and indicative range polygons have not been treated as precise occurrence coordinates.

A defensible run needs dated, independently attributable records, coordinate uncertainty, duplicate and captive-record checks, layer versions and regional scope. Preference and absence require additional survey-effort and detection evidence.

Habitat limitations and contrary evidence: No supported exclusion recorded

Not recorded is not the same as cannot occur. Low suitability, resident habitat, breeding habitat and occasional movement are different conclusions.

This library has not established a vegetation, ecosystem or soil-type exclusion for this species. This does not mean all habitat is suitable; the evidence needed to justify an exclusion has not been assembled.

Habitat limitations and contrary evidence: Before using a negative association

  • Confirm the taxon, geographic region, life stage and habitat function covered by the evidence.
  • Check survey methods, season, repeated effort and detectability before interpreting non-detection.
  • Investigate credible contradictory records and microhabitats absent from broad mapping.
  • Do not convert a missing map class, low record count or failed data request into species absence.

Before disturbance: 1. Desktop and approvals

Confirm whether the project could affect the species before works begin.

Check national mapping, state records and recent surveys for the site. An action likely to have a significant impact on this nationally listed species needs EPBC Act referral, and state permits apply where it is state listed.

Before disturbance: 2. Plan to avoid

Design the footprint, timing and access to avoid known or likely habitat, and brief crews on what to look for and who to call.

During disturbance: 1. Controls

Keep works inside the approved footprint and conditions.

Fence or mark habitat to be retained and keep machinery, stockpiles and spoil out of it.

During disturbance: 2. Stop and report

If the species is found unexpectedly, stop work at that spot and contact the project ecologist and the relevant agency.

After disturbance: 1. Records

Record outcomes.

Record sightings, habitat lost or retained and any injury or death, and report them under the approval conditions.

Rehabilitation: 1. Restore

Restore disturbed habitat where possible.

Reinstate disturbed ground with local species, return logs, rocks and litter, and control weeds and erosion until the site is stable.

Sources