Centromerus semiater
Key Details
| Taxonomic Groups: | Invertebrate > spider (Araneae) > Spider |
| Red List Status: | Endangered (Not Relevant) [EN(nr)] |
| D5 Status: | Included in the baseline Red List Index for England (Wilkins, Wilson & Brown, 2022) |
| Section 41 Status: | (not listed) |
| Taxa Included Synonym: | (none) |
| UKSI Recommended Name: | Centromerus semiater |
| UKSI Recommended Authority: | (L. Koch, 1879) |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | Harvey et al., 2017 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | EN, criteria: B2ab(ii): recorded in only 2 GB hectads (/5, all in E Anglia) since 2000. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Much more restricted than its E. Anglian fen litter habitat |
| Question 3: | At a landscape scale, would the species benefit from untargeted habitat management to increase habitat mosaics, structural diversity, or particular successional stages? |
| Response: | No |
| Justification: | This species would not benefit from untargeted management |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Low - Relict or natural rarity |
| National Monitoring Resource: | Combination - insufficient |
| Species Comments: | Found in fen and open fen carr litter and moss. Recorded in numbers at some sites. |
Key Actions
Key Action 1
Proposed Action: Targeted re-survey of recorded and nearby sites, using standardised methodology to assess current status (and establish baseline for national monitoring programme)
Action targets: 2. Biological status assessment exists
Action type: Status survey/review
Duration: 2 years
Scale of Implementation: ≤ 5 sites
High priority sites: Sutton and Catfield Fens, Woodbastwick Marshes and Wheatfen, Norfolk; Wicken Fen, Cambs.
Comments: Prioritise re-survey of Wicken Fen (last record there 1928)
Key Action 2
Proposed Action: Autecological research to better characterise habitat requirements and inform management
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: 1 site
High priority sites: Sutton Fen, Norfolk
Comments: Use most reliable recent site
Key Action 3
Proposed Action: Ensure site managers are aware of species past/recent presence and vulnerability on their sites. Update them with Action 1 and 2 results to provide any resulting guidance on locations/management and inform commissioning of invertebrate survey work (methods likely to detect/damage species, need for retention and examination of spider by-catch when not a survey target)
Action targets: 5. Remedial action identified
Action type: Advice & support
Duration: >10 years
Scale of Implementation: ≤ 5 sites
High priority sites: Sutton and Catfield Fens, Woodbastwick Marshes and Wheatfen, Norfolk; Wicken Fen, Cambs.
Comments: Ensure species is notified to the Broads Authority biodiversity staff, plus assemble mailing list and update site managers directly, at species-appropriate intervals; most easily delivered by BAS/SRS.
Acknowledgment:
Data used on this website are adapted from Threatened species recovery actions 2025 baseline (JP065): Technical report and spreadsheet user guide (Natural England, 2025). Available here.