Dun Sentinel
Assiminea grayana
Assiminea grayana, common name the "dun sentinel", is a species of very small (4–6 mm.) salt marsh snail, a terrestrial (or marine gastropod mollusk in the family Assimineidae.
12
Countries
Photo: iNaturalist: (c) nevermetsnails, some rights reserved (CC BY-NC), uploaded by nevermetsnails
Taxonomy & Classification
Kingdom
Animalia
Phylum
Mollusca
Class
Gastropoda
Order
Littorinimorpha
Family
Assimineidae
Genus
Assiminea
Dun Sentinel belongs to the family Assimineidae, order Littorinimorpha, within the Gastropoda class.
Species Profile
Assiminea grayana, common name the "dun sentinel", is a species of very small (4–6 mm.) salt marsh snail, a terrestrial (or marine gastropod mollusk in the family Assimineidae.
The Dun Sentinel (Assiminea grayana) is declining primarily due to habitat loss and degradation of its specialized saltmarsh and estuarine environments. Coastal development, pollution, and sea-level rise associated with climate change are reducing the availability of suitable intertidal habitats where this small gastropod can survive.
Key Facts
Habitat & Distribution
This species lives in habitats that are intermediate between land and saltwater: in estuaries and salt marshes, at, or right above, the high tide level.
Threats
IUCN Red List: Endangered
The Dun Sentinel (Assiminea grayana) is declining primarily due to habitat loss and degradation of its specialized saltmarsh and estuarine environments. Coastal development, pollution, and sea-level rise associated with climate change are reducing the availability of suitable intertidal habitats where this small gastropod can survive.
Coastal development and urbanization
Habitat degradation from pollution
Alteration of tidal regimes
Sea-level rise and climate change
Found in 12 Countries
National vs Global Threat Status
How this species is assessed at the national level compared to its IUCN global status (EN).
| Country | National Status | Global Status | Comparison |
|---|---|---|---|
| EU | LCLeast Concern | ENEndangered | Lower local risk |
| EU | LCLeast Concern | ENEndangered | Lower local risk |
| EU | LCLeast Concern | ENEndangered | Lower local risk |
| EU | LCLeast Concern | ENEndangered | Lower local risk |
National Red List data sourced from the National Red List Project (nationalredlist.org, ZSL) and country-specific Red List authorities.
Community Sightings
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Sources & Attribution
How to Cite
IUCN: IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-1. Available at: https://www.iucnredlist.org. doi:10.2305/IUCN.UK.2025-1.RLTS
GBIF: GBIF.org (2025). GBIF Home Page. Available at: https://www.gbif.org
National Red Lists: ZSL (2025). National Red List. Zoological Society of London. Available at: https://www.nationalredlist.org
This page: SpeciesRadar (2025). Dun Sentinel (Assiminea grayana). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/dun-sentinel