Mysterious Calommata Purse-Web Spiders Rediscovered in Africa

Posted on May 17, 2011

Researchers have rediscovered very poorly known purse-web spiders of the genus Calommata in Africa. Four of the species described are new to science.

Purse-web spiders construct a purse-shaped web of dense silk that covers a chamber. The spider waits in the chamber for wandering prey to step on the web. Then the spider impales its prey from beneath with its exceptionally long fangs. This diagram gives you a good idea of how purse-web spiders catch prey.

Little is known about the African purse-web spiders because they are extremely difficult to locate in nature. The burrows of the African species have never been photographed, and the first ever photograph of a live African Calommata male, captured in a pitfall trap, was taken only last year by Ian Engelbrecht. The spider shown on the photo (Calommata transvaalica male) is only 6.3 mm in length.

The researchers are from the University of the Free State in South Africa (Rene Fourie and Charles Haddad) and the Royal Museum for Central Africa in Belgium (Rudy Jocque). The study was published in the open access journal ZooKeys.

Study author Charles Haddad says, "While Calommata spiders have been collected elsewhere in Africa throughout the last century, albeit on rare occasions, our study was prompted by the recent rediscovery of these spiders in South Africa, nearly eight decades since the last specimen was collected here in 1923. Currently six African species are recognised, with an additional six species from East Asia and Israel."

SPIDERS