Velvetworms
Peter Swart, April 2026
Velvetworms found during the Cave Invertebrate Atlas Project. The list is not exhaustive.
Velvetworms of the phylum Onychophora have been found in caves of the Cape Peninsula, but are rare. The Phylum is represented by 2 species. Peripatopsis alba is troglobitic and is only known from caves, where as Peripatopsis balfouri sometimes uses cave environments, but is not tied to caves.
| Species | Observations | Image |
|---|---|---|
| Peripatopsis alba | 1 Observation |  |
| Peripatopsis balfouri | 2 observations |  |
Area of Observations
During the course of this project, only 3 velvet worms have been observed. One Peripatopsis alba in Inukshuk Cave and two small Peripatopsis balfouri in Boomslang Cave. One of the Peripatopsis balfouri was found dead, floating on the surface of a highly contaminated pool of water. The water had an oily slick floating on the surface, and a plastic jar of what looked like aqueous cream next to the pool. I appears that someone had washed their hands in the water. Apart from the dead peripatus, there were at least 3 dead centipedes in the water.
Habitat and Distribution
Peripatopsis alba is only known from the Wynberg Cave system and surrounds, including Smugglers Cave and Vivarium Cave. This animal has a very limited range, probably no more than 1km long by 100m wide. Within this limited range it is extremely rare. Although Peripatopsis alba is sometimes found in shallow caves close to the surface, it is also found deep into the dark zone of the bigger system like Wynberg Cave and at the bottom of Bats Cave.
Peripatopsis balfouri has been found in Blue Peripatus Cave on Table Mountain, in Boomlslang Cave on Kalk Bay Mountain, and is known from Newlands forest, on the slopes of Table Mountain. Both specimens from Boomslang Cave were in the dark sections of the cave, but were within approximately 50m of a known entrance.
Description
Peripatopsis alba
- Length: 32mm-48mm
- Legs: 18 pairs of clawed legs, last pair reduced
- Colour: pure white
- Ref: Peripatopsis alba
Peripatopsis balfouri
- Length: 9mm-22mm
- Legs: 17 to 19 pairs
- Colour: blue/grey, sometimes with a white head
- Ref: Peripatopsis balfouri
Behaviour
One Peripatopsis alba was found on a rocky wall while the other was found on the cave floor. The wall on which the specimen was hunting was covered in a layer of fine roots. It hunts by spraying a sticky slime at its prey. It has also been known to spray the slime at a photographer.
One Peripatopsis balfouri was found dead, floating on a pool. This specimen was blue in colour. The other was found on a rock wall in Boomslang Cave, and dropped off the wall and curled up to escape the photographer. This specimen was grey. It stayed curled up for at least 5 minutes.