Pink velvet worm  (Opisthopatus roseus)

Classified as Critically Endangered (CR B1ab(i,iii)) on the IUCN Red List 2006 (1).

Velvet worms belong to a phylum of their own, the Onychophora, meaning 'claw-bearers' (3), and are a fascinating group of ancient, caterpillar-like animals that have changed little over the last 400 million years (4). These small, delicate-looking animals have long fascinated scientists, being described as a ‘missing link’ between arthropods (a group that includes insects and spiders) and annelids (segmented worms) due to their unusual combination of features (3). Ringed antennae are positioned on top of the head, with eyes near the base (5), and there are 18 pairs of stumpy, un-jointed, clawed legs down the whole length of the body (3). Once thought to be extinct (6), the pink velvet worm is distinguished from other Onychophorans by its deep, dusky, rose-pink colouration (1) (2). The surface of velvet worms is covered with numerous papillae, comprised of delicate rows of overlapping scales that make it water repellent, which is useful in their moist habitats (3). Tiny hairs at the tip of the papillae are sensitive to touch and smell, and it is these scales and hairs that give these worms the velvety appearance that has earned their common name (3) (5).

Recorded only from the Ngele Forest in KwaZulu-Natal, South Africa (1).

Inhabits the forest floor of indigenous Afromontane forest, in rotting logs and amongst moist leaf litter (1) (2).

Velvet worms are voracious and active carnivores, feasting on other small invertebrates such as termites, woodlice, small spiders and small molluscs (3) (7). These animals are largely nocturnal and have an interesting and unusual hunting technique (5). To capture their prey, these worms squirt a sticky white liquid from their oral tubes, which entangles their quarry (3) (7). Digestive juices are then secreted into the prey’s body, and partially-digested tissue is sucked up (5). The sticky slime is also squirted at potential predators in self-defence, giving the velvet worm more time to escape (3) (7).

Female pink velvet worms give birth to live young, which are known to be carried and develop in a uterus for several months (2). Indeed, for other members of the family in South Africa, gestation is approximately 12 to 13 months (1). About 30 young are thought to be produced each year, which resemble adults (2). Although little is known of the life history of the pink velvet worm, other Peripatopsidae reach sexual maturity at 9 to 11 months and the life span is about six to seven years (1).

The Ngele Forest in which the pink velvet worm lives was heavily logged in the early 1900s, after a private sawmill was built nearby in 1891 (1). The remaining forest is patchy and continues to be destroyed as exotic plantations are planted around and right up to the edges of the indigenous forest, the harvesting of which is greatly disruptive to the forest (1). Timber plantations are also associated with a high level of invasion by alien plants. The construction of a national road through Ngele Forest has fragmented habitat and potentially populations of the pink velvet worm.

Although a permit is required to collect any animals from the province and some degree of habitat protection has been given by the State, access to the area where this species occurs remains relatively uncontrolled (1). Future conservation measures advocated include a publicity campaign to raise awareness of the species, and further research on population numbers, range and biology of the species (1). Fortunately, five specimens are currently thriving in captivity in Hamburg, providing the opportunity to study their life cycle, reproduction and feeding behaviour (6). Although this captive population safeguards the survival of the species for the time being, more needs to be done to protect the pink velvet worm’s diminishing, restricted habitat if this ancient, unusual and elusive species has any chance of surviving in the wild.

View information on this species at the UNEP World Conservation Monitoring Centre.

For more information on conservation in South Africa, see:

• WWF:
  http://www.wwf.org.za/
• Conservation International:
  http://www.conservation.org/explore/africa_madagascar/pages/overview.aspx
• African Conservation Forum:
  http://www.africanconservation.org/