Stephanopis altifrons
Knobbly Crab Spider Identification in Australia
Camouflaged Australian bark crab spider with a knobbly brown-black body, often sitting still on bark, leaves or a folded-leaf retreat.
Usually low riskThe Knobbly crab spider is Stephanopis altifrons, a cryptic bark crab spider that relies on camouflage and ambush rather than a capture web. It is useful to compare when a lumpy brown or grey spider appears flattened against bark, leaves or a sheltered garden surface with the front legs held crab-style. The current taxonomic revision also absorbs several former Stephanopis names into S. altifrons, so older labels may look more species-specific than the evidence allows.
Quick identification
- Small bark-crab body with front legs held out to the sides
- Knobbly or irregular outline that can look like bark, lichen or debris
- Brown, grey, black or pale markings that blend with bark and leaf litter
- Usually sits still on bark, leaves or a folded-leaf retreat rather than in a capture web
What to check next
Check for the crab-like stance, lumpy bark camouflage and a still ambush posture. A folded leaf with silk or a spider guarding an egg sac supports the behaviour, not the exact species. Compare with other Stephanopis, Sidymella and flower crab spiders when the body outline or locality is uncertain.
When to seek medical help
This spider is not usually considered dangerous. Avoid handling it and seek medical advice for severe pain, allergic symptoms, infection signs, spreading symptoms or uncertainty after any bite.
Where it is usually seen
Tree bark, leaves, shrubs, garden plants, bushland edges and sheltered outdoor surfaces in Queensland, New South Wales and Tasmania, where camouflage helps it ambush small prey.