
Ash-black Slug
Limax cinereoniger
The Ash-black Slug (Limax cinereoniger) is one of Europe's largest terrestrial gastropods, reaching lengths of up to 20 centimeters. This distinctive mollusk is characterized by its dark gray to black coloration and prominent keel running along its back.
Photo: Wikimedia Commons (CC) via https://en.wikipedia.org/wiki/Limax_cinereoniger
Taxonomy & Classification
Kingdom
Animalia
Phylum
Mollusca
Class
Gastropoda
Order
Stylommatophora
Family
Limacidae
Genus
Limax
Ash-black Slug belongs to the family Limacidae, order Stylommatophora, within the Gastropoda class.
Species Profile
The Ash-black Slug (Limax cinereoniger) is one of Europe's largest terrestrial gastropods, reaching lengths of up to 20 centimeters. This distinctive mollusk is characterized by its dark gray to black coloration and prominent keel running along its back. Historically distributed across parts of central and western Europe, the species has experienced severe population declines and range contractions over recent decades. The Ash-black Slug inhabits mature deciduous and mixed forests, particularly favoring beech and oak woodlands with rich leaf litter and high humidity levels. It requires undisturbed forest environments with stable microclimatic conditions and abundant organic matter for feeding. The species faces multiple threats that have contributed to its critically endangered status. Habitat destruction and fragmentation through deforestation, urban development, and intensive forestry practices have eliminated much of its suitable habitat. Climate change poses additional challenges by altering temperature and moisture regimes essential for the species' survival. Air pollution, particularly acid rain, has degraded forest ecosystems and may directly impact slug populations. The species' limited dispersal ability and specific habitat requirements make it particularly vulnerable to environmental changes. Conservation efforts focus on protecting remaining old-growth forest habitats and implementing sustainable forest management practices. Some European countries have established monitoring programs to track remaining populations, though comprehensive surveys remain limited. Habitat restoration projects in former range areas show promise, but recovery efforts are complicated by the species' slow reproduction rate and sensitivity to environmental disturbance.
The Ash-black Slug faces severe threats from habitat destruction through deforestation and urban development, which has fragmented and eliminated much of its required old-growth forest habitat. Climate change and air pollution further degrade the stable, humid forest conditions essential for the species' survival.
Key Facts
Habitat & Distribution
The species inhabits mature deciduous and mixed forests, particularly beech and oak woodlands with rich leaf litter layers. It requires undisturbed forest environments with high humidity, stable temperatures, and abundant organic matter.
Threats
IUCN Red List: Critically Endangered
The Ash-black Slug faces severe threats from habitat destruction through deforestation and urban development, which has fragmented and eliminated much of its required old-growth forest habitat. Climate change and air pollution further degrade the stable, humid forest conditions essential for the species' survival.
Detailed threat classification data is sourced from IUCN assessments as they become available.
National vs Global Threat Status
How this species is assessed at the national level compared to its IUCN global status (CR).
| Country | National Status | Global Status | Comparison |
|---|---|---|---|
| EU | LCLeast Concern | CRCritically Endangered | Lower local risk |
| EU | LCLeast Concern | CRCritically Endangered | 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). Ash-black Slug (Limax cinereoniger). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/ash-black-slug