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Carnarvon and Murchison Fairy Shrimp (Branchinella wellardi)

Branchinella wellardi is an Australian fairy shrimp known from Western Australia and some inland areas of eastern Australia. Its WA distribution and ecology are poorly documented, so works near suitable water bodies should include a precautionary assessment. It is listed as Priority 3 on the DBCA Threatened and Priority Fauna List, a DBCA priority category rather than a listing under the Biodiversity Conservation Act 2016.

Conservation status

Western Australia, WA Threatened and Priority Fauna List: Priority 3.

Seasonal considerations

No species-specific activity or breeding months are known. The row below is a planning prompt only, not a known seasonal pattern.

Known timing: Activity, breeding and movement months have not been documented.

The timing of activity or detectability for B. wellardi is not known.

  • Survey planning: Planning window only. No species-specific seasonal window is known; assess site conditions and water availability at the time of survey.

Identification: Appearance and size

Species-level identification relies on small anatomical features described from specimens. Body measurements and a complete field description are not available.

The species is a fairy shrimp in the crustacean genus Branchinella. Its overall appearance and body length have not been documented.

The male frontal appendage has a short trunk and two branches. The male fifth thoracopod has distinctive knobs on the medial surface of its endopod, reported as unique to B. wellardi among the species discussed.

Identification: Similar species

Branchinella herrodi is identified as a closely related species. The reported knobs on the medial endopod of the fifth thoracopod distinguish B. wellardi from B. herrodi.

A practical comparison with all other fairy shrimp that may occur at a site is not available.

Identification: Field signs

Species-specific field signs, such as eggs, resting stages or visible habitat indicators, have not been described.

Treat a field identification as provisional unless diagnostic features are confirmed by a suitably experienced invertebrate taxonomist.

Distribution: Known range

Records are sparse, and the species has been encountered only a few times. The exact locations of most Western Australian records are not known.

The species was first discovered in the Murchison district of Western Australia. It has since been recorded a few more times in mid Western Australia, and from a few sites in the Paroo, north-western New South Wales and south-western Queensland.

A 2010 specimen record is from Muella Station in New South Wales. The species is endemic to Australia.

Distribution: Western Australian records

Atlas of Living Australia records show three WA records at three distinct 0.1-degree locations, between latitude -28.3 and -27 and longitude 116.6 and 120.5. Records outside WA in that summary were excluded as likely errors.

The DBCA list flags the Midwest region. The common-name area is Carnarvon and Murchison, but precise WA collection sites are not identified.

Distribution: Listing

In WA, B. wellardi is Priority 3, described as poorly known, known from several locations and not under imminent threat.

There is no national listing.

Habitat: Recorded setting

Habitat information is limited. One collection record is associated with a temporary lake outside WA, while habitat details for WA records are not documented.

A specimen was collected at a temporary lake on Muella Station in New South Wales. This setting may not be representative of all occupied sites.

Habitat: Information gaps

The water chemistry, depth, vegetation, substrate, catchment and hydroperiod of WA sites are not documented.

Do not assume that every temporary water body, or every site within the recorded regions, is occupied.

Foraging habitat: Diet and feeding

The species’ diet and feeding behaviour have not been documented.

Diet, feeding method and food resources are not known.

Foraging habitat: Site assessment

Do not use the presence or absence of a particular food resource as an indicator of whether B. wellardi is present.

For general site assessment, record water and habitat conditions without treating them as species-specific feeding requirements.

Breeding habitat: Known information

Breeding habitat and reproductive timing are poorly known.

Adult male and female specimens have been described, but breeding dates, egg numbers, development time and specific breeding-site conditions are not known.

Breeding habitat: Precaution

If suitable water bodies are present within a works area, assess them before disturbance rather than relying on an assumed breeding season.

Do not infer that a dry site is unoccupied or that a wet site is a confirmed breeding site.

Sheltering habitat: Known information

Sheltering sites and resting stages have not been documented.

Where B. wellardi shelters, persists between wet periods or deposits resting stages is not known.

Sheltering habitat: Works precautions

Do not assume that only visible animals or visibly wet areas are relevant. Where a water body or its margins may be affected, seek ecological advice before ground or water disturbance.

Threats: Known pressures

No species-specific threats have been identified. Its WA priority status reflects that it is poorly known, rather than a particular documented impact.

Threats to B. wellardi and observed impacts at its recorded sites have not been reported.

Threats: Risk management

As a general precaution for works near water bodies, avoid unassessed changes to water levels, water quality or the physical footprint of a site where the species could occur.

Record potential impacts and refer uncertain identifications or habitat decisions to the project ecologist.

Survey methodology: 1. Desktop assessment

No species-specific survey method or detectability information is known. Survey design should be precautionary and documented as an assessment approach, not a validated protocol for this species.

Check current fauna records, project-area information and the DBCA priority fauna listing. Give particular attention to the Midwest and to the broader Carnarvon and Murchison area.

Do not assume the species is absent because no records are mapped.

Survey methodology: 2. Site inspection

Inspect water bodies and their margins where these occur within or near the works footprint. Record whether water is present and describe site conditions, survey dates and access limitations.

Because one record is from a temporary lake, consider whether water availability may affect the opportunity to detect fairy shrimp. A suitable survey season or reliable detection window for B. wellardi is not known.

Survey methodology: 3. Identification and records

For general fairy shrimp survey practice, use appropriate aquatic sampling methods only where authorised and suitable for the site, and minimise disturbance to the water body.

Record specimens or images and obtain expert confirmation where possible. The diagnostic anatomical characters described for B. wellardi may require examination beyond a casual field observation.

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 habitat disturbance: 1. Review records and design

Plan works around the limited distribution and habitat information, and check for water bodies before clearing or earthworks begin.

Have the project ecologist review available records and the proposed disturbance footprint, including access routes and drainage works.

Where practicable, avoid or reduce disturbance to water bodies and their margins until their ecological value has been assessed.

Before habitat disturbance: 2. Brief the work team

Brief spotter catchers, ecologists and clearing crews that B. wellardi is poorly known and that absence from a brief inspection does not confirm absence from a site.

Set out a clear stop-work and escalation process for unexpected aquatic fauna or previously unassessed water bodies.

During habitat disturbance: 1. Maintain controls

Use precautionary controls if works approach a water body that has not been assessed or where aquatic fauna are encountered.

Keep clearing and vehicle movements within the approved footprint. Avoid unnecessary entry into water bodies and their margins.

Prevent avoidable sediment, contaminants or debris from entering water. These are general site precautions, not documented species-specific threat pathways.

During habitat disturbance: 2. Respond to finds

If fairy shrimp or other unexpected aquatic fauna are found, pause the affected activity where safe to do so and notify the project ecologist.

Do not handle or relocate animals unless this is authorised and directed by a suitably qualified person.

After habitat disturbance: 1. Record and review

After works, document what was affected and check that agreed controls remain in place.

Document any fauna observations, changes to water bodies, control measures and incidents. Pass relevant records to the project ecologist for review.

Update the site assessment if the works reveal water bodies or conditions not considered before disturbance.

After habitat disturbance: 2. Monitor controls

Check that disturbed areas and any retained water bodies are managed in line with project requirements. Do not interpret a lack of later observations as proof that the species is absent.

Rehabilitation actions: 1. Restore affected areas

No species-specific rehabilitation methods are known. Rehabilitation should be guided by the site assessment and project approvals.

Rehabilitate disturbed ground and drainage features in accordance with the approved design, taking care not to create unassessed changes to nearby water bodies.

Use site-appropriate methods determined by the project ecologist. Vegetation, substrate and water conditions required by B. wellardi are not known.

Rehabilitation actions: 2. Follow up

Record rehabilitation outcomes and any fauna observations. Review the approach if monitoring identifies unexpected changes to water bodies or aquatic fauna.

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