Five species of velvet worms were discovered in and around the Garden Route National Park (GRNP) by independent researchers from the University of Stellenbosch, Aaron Barnes, Till Reiss and Savel Daniels.
Vuyiswa Thabethe, General Manager of the Garden Route National Park (GRNP) indicated that the Park has received the news with excitement and that “not only are we in the midst of age-old wonder creatures dating back as far as 5 million years ago, velvet worms thrive in pristine conditions only. Their existence in the forest point to how well the forests are managed under the GRNP. The forests are healthy and thriving.”
Areas of study by Barnes, Reiss and Daniels are mostly situated in the GRNP and surrounds, including Diepwalle, Goudveld, Groeneweide, Garden of Eden (Harkerville), Wilderness (Brown Hooded Kingfisher trail, Beervlei, Half Collared Kingfisher Trail, Woodville Big tree). Areas outside the Park include the Robinson’s pass, Witfontein, Jonkersberg, Homtini, Tulbagh.
Velvet worm movement is highly restricted, explains Barnes. “They can only occur and move between pristine forest habitats, living within dead and rotting logs in Afrotemperate forests.”
The purpose of the study was to revise information previously collected through sampling efforts on the Cape species of velvet worms (Peripatopsis clavigera). A study in 2009 collected 8 samples only. The recently completed study in 2019 by Barnes, Reiss and Daniels sustainably collected some 110 odd samples focussing on large forest complex patches and surrounding farms.
Another reason for the study was to understand the evolution of the species.
The indigenous forests of the Garden Route National Park (GRNP) presents a unique system for research. The Park, being made up of scattered patches of protected areas comprising Afrotemperate forests and fynbos areas are mosaicked between commercial plantations, farmlands and private lands all having different land-use practices. This continuously changing open system creates a unique “playground” attracting numerous researchers and for discovering new species.
The most recent discovery is that of five new velvet worm species found in the Afrotemperate forests of the Garden Route. During an extensive fine-scale study of the Peripatopsis clavigera species complex, Stellenbosch University researchers Aaron Barnes, Savel Daniels and Till Reiss found that this species, formerly grouped as the Knysna velvet worm, actually comprises five different species that separated during the Plio–Pleistocene over 5 million years ago.
Researchers expected to find three (3) isolated species at the most, in geographically discrete areas. Instead, velvet worms were found distributed among many forest patches, sometimes with different species in the same log.
The fragmented Afrotemperate Southern Cape forests were shaped by ancient climatic conditions, characterised by alternate wet and dry conditions. This had an impact on the distribution of the species as forests expanded and contracted in response. “That is how they speciated” explains Barnes. “Populations were likely widely distributed across expansive forests during wet conditions and confined to smaller forest fragments under dry conditions. Being unable to move between these smaller patches of forest, they speciated. The unusual distribution of species that we see today is most likely due to repeated cycles of this process over millions of years.”
South Africa has two genera, namely, Peripatopsis and Opisthopatus. Peripatopsis occurs majorly in the Cape and Opisthopatus in the North-Eastern areas of the country such as KwaZulu Natal and Mpumalanga.
The Knysna velvet worm known as the Peripatopsis clavigera is part of the Peripatopsis genus. The additional species discovered forming part of Peripatopsis include P. ferox, P. mellaria, P. edenensis, P. mira and P. tulbaghensis.