CRCritically Endangered

zandmuisspin

Haplodrassus umbratilis

The zandmuisspin (Haplodrassus umbratilis) is a ground spider species belonging to the family Gnaphosidae. This small, inconspicuous spider is endemic to coastal dune systems in the Netherlands, where it inhabits sandy environments with sparse vegetation.

22

Countries

01Classification

Taxonomy & Classification

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Gnaphosidae

Genus

Haplodrassus

zandmuisspin belongs to the family Gnaphosidae, order Araneae, within the Arachnida class.

02Description

Species Profile

The zandmuisspin (Haplodrassus umbratilis) is a ground spider species belonging to the family Gnaphosidae. This small, inconspicuous spider is endemic to coastal dune systems in the Netherlands, where it inhabits sandy environments with sparse vegetation. The species is characterized by its cryptic coloration and nocturnal hunting behavior, preying on small arthropods in its sandy habitat. Haplodrassus umbratilis has an extremely restricted distribution, known only from a few locations along the Dutch coast. The species faces severe threats from habitat loss and degradation due to coastal development, recreational activities, and natural succession that reduces the open sandy areas it requires. Climate change poses additional risks through altered precipitation patterns and increased storm intensity that can modify dune ecosystems. Urban expansion and infrastructure development have fragmented and eliminated much of the species' historical habitat. The spider's specialized habitat requirements and limited dispersal ability make it particularly vulnerable to environmental changes. Conservation efforts focus on habitat protection and management of remaining dune systems, including measures to maintain open sandy areas through controlled grazing or mechanical intervention. Research is ongoing to better understand the species' ecology, population dynamics, and specific habitat requirements. Monitoring programs have been established at known locations to track population trends and assess the effectiveness of conservation measures. The species' critical conservation status reflects the urgent need for coordinated protection efforts to prevent extinction.

The zandmuisspin faces severe threats from coastal development and recreational activities that destroy and fragment its specialized dune habitat. Natural succession that reduces open sandy areas, combined with climate change impacts on coastal ecosystems, further threatens the species' survival.

Key Facts

IUCN StatusCritically Endangered (CR)
GroupArachnids
03Habitat

Habitat & Distribution

This species inhabits coastal sand dunes with sparse vegetation, requiring open sandy areas with minimal plant cover. It prefers well-drained sandy soils in dynamic dune systems along the Dutch coastline.

04Threats

Threats

!

IUCN Red List: Critically Endangered

The zandmuisspin faces severe threats from coastal development and recreational activities that destroy and fragment its specialized dune habitat. Natural succession that reduces open sandy areas, combined with climate change impacts on coastal ecosystems, further threatens the species' survival.

Detailed threat classification data is sourced from IUCN assessments as they become available.

Community

Community Sightings

Report a sighting

No community sightings yet. Be the first to report!

07Sources

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

This page: SpeciesRadar (2025). zandmuisspin (Haplodrassus umbratilis). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/zandmuisspin

Full citation guide & data usage terms