- Common name: White Velvetworm
- Location: Wynberg Cave, Table Mountain
- Reference: 2011105
- Photographer: G Giribret
REPRINT SASA Bulletin April 1957 CAVE FAUNA : NO. 3 by J.R. Grindley, B.Sc (Hons.)
"The White Peripatus - Peripatopsis alba Lawrence". The white Peripatus, (Peripatopsis alba), first described by Lawrence in 1931, is one of the rarest and most interesting creatures found in our caves. It was originally discovered in Wynberg Cave, but has since been located in Bats Cave and Smugglers Cave as well.
It is a pure white elongate creature in appearance somewhat like a caterpillar and about two inches long. It is blind and eyeless. There are eighteen pairs of legs, each with two minute claws. The last (genital) pair of legs are extremely short. In the male the 2nd last pair is very noticeably shorter than the preceding pair. The foot is much longer than in any other peripatus and the legs themselves are long and slender compared to the short stumpy legs of most Peripatus species. The skin appears velvety owing to being covered with minute papillae. Each of the segments of the body is divided into 8 or 9 annulations. There are no coxal organs.
Peripatus alba resembles the ordinary P. Balfouri in many features. It is however a clearly distinct species and not just a blind and unpigmented mutant. One of the most obvious of the many differences is that although they both have the same number of legs they are much longer in P. alba. The peculiar group of animals to which the Peripatus belongs is called the Onycophora which means nail-bearing and refers to the little claws on their feet. The group is intermediate between the worms and the arthropods. A study of their anatomy reveals some organs to be typically annelid and others typically arthropod. There is therefore perhaps some excuse for the confusion over their nature in the local press, where they have been described as "slimy horrors" and "slugs with legs".
Peripatis Alba is the only cave dwelling Onycophora in the world and Lawrence considers that it is "probably the most typical cavernicolous animal yet encountered in South Africa". The fact that there is absolutely no trace of pigment is particularly remarkable as most peripati are strongly coloured. The loss of pigmentation and eyes and the elongation of the legs is characteristic of cave animals. Peripatus alba probably feeds on worms and small soft-bodied arthropods like other peripati, but we have no actual observations to substantiate their diet to date.
The normal habitat of most Onycophora under damp logs and stones does not differ greatly from the cave habitat. The white peripatus is in fact protected from fires and drought and erosion which have so reduced the numbers of their outside relatives in the Cape Peninsula. If they are not destroyed by inquisitive visitors to caves they may far outlast their relatives, isolated as they are in their dark, damp dungeons.
Reference: Lawrence, R.F. (1931) "A New Peripatopsis from the Table Mountain Caves" Annual of the South African Museum 30, pp. 101 - 107.