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Caviphantes saxetorum

Unknown

Overview

The elvebreddvergedderkopp (Caviphantes saxetorum) is a small sheet weaver spider endemic to rocky crevices and cliff faces in Scandinavian regions. This diminutive arachnid constructs delicate horizontal webs between rock formations and displays a distinctive pale coloration with darker markings that provide excellent camouflage against lichen-covered stone surfaces. As a specialized predator of small flying insects in alpine and subalpine environments, it plays a crucial role in controlling midge and small fly populations in these harsh ecosystems.

Climate change poses the primary threat to this species as warming temperatures alter the microclimate conditions within its specialized rocky habitat refugia. Additionally, increased recreational climbing and tourism in Scandinavian mountain regions leads to direct disturbance of web structures and potential trampling of critical breeding sites in accessible cliff areas.

Threat summary

Habitat

This species exclusively inhabits narrow crevices and overhanging ledges on limestone and granite cliff faces at elevations between 800-1,400 meters in Norway and Sweden. The spiders require specific microclimatic conditions found in partially shaded rock fissures that maintain consistent humidity levels and protection from extreme weather while providing adequate prey corridors.

Frequently asked questions

Why is Caviphantes saxetorum classified as Endangered?
Caviphantes saxetorum is classified as Endangered — facing a very high risk of extinction in the wild — because population numbers are declining steeply and key habitats are under sustained pressure. Climate change poses the primary threat to this species as warming temperatures alter the microclimate conditions within its specialized rocky habitat refugia. Additionally, increased recreational climbing and tourism in Scandinavian mountain regions leads to direct disturbance of web structures and potential trampling of critical breeding sites in accessible cliff areas.
Where does Caviphantes saxetorum live?
Caviphantes saxetorum occurs in Austria, Belgium, Canada, France, Germany, and Norway (plus 3 other countries). Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to Caviphantes saxetorum?
The main threats to Caviphantes saxetorum are habitat loss and human disturbance. The full IUCN-classified threat record for this species is detailed on the species page.

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