The faunistic diversity of spiders (Arachnida: Araneae) of the South African Cape Floristic Kingdom

Abstract

Spider species distribution in the Cape Floristic Kingdom (CFK) was compiled as part of the South African National Survey of Arachnida (SANSA), whose main aim was to create a relational database for the country’s arachnid fauna. Data from the CFK was extracted from taxonomic and faunistic published papers, as well as unpublished faunistic survey data in national collections. A total of 11 500 records from 130 localities were recorded in the CFK until the end of 2023, representing 62 families, 334 genera and 960 species, with two further families (Synotaxidae and Theridiosomatidae) only known from undescribed species. This represents 42.4% of the total spider fauna of South Africa. For each species, the global and CFK distribution, as well as the level of endemicity and a conservation assessment using the IUCN Red List criteria, are provided. A total of 269 spp. (28.0%) are endemic to the CFK, 49 spp. (5.1%) are of special concern, and 229 spp. (23.9%) are Data Deficient. However, most of the species (682 spp., 71.0%) have a wide distribution with no known threats and are categorised as Least Concern. Salticidae is the most species-rich family (128 spp.), with 30 spp. endemic to the CFK, followed by the Gnaphosidae (107 spp.), Thomisidae (86 spp.) and Lycosidae (49 spp.), while six families are represented by a single species. The last decade has seen an exponential growth in the knowledge of spiders in South Africa, and there are certainly many more species that must still be discovered and described.

Keywords:

• abundance
• conservation status
• endemicity
• Fynbos Biome
• global distribution
• South African National Survey of Arachnida

ACKNOWLEDGEMENTS

This paper is dedicated to the memory of our late colleague and co-author, Stefan Foord, whose incredible contribution to the success of SANSA as an ecologist, data analyst and taxonomist will be sorely missed in the years to come. The authors would like to thank the Agricultural Research Council (ARC) and the South African National Biodiversity Institute (SANBI), Threatened Species Programme for funding the South African National Survey of Arachnida (SANSA) phase 2. CapeNature and SANParks are thanked for permits and facilitating projects to collect in the reserves and national parks. We acknowledge support from the DST-NRF Centre for Invasion Biology and the National Research Foundation of South Africa. The staff of the Arachnology section of the ARC –National Collection of Arachnida and the National Museum, Bloemfontein are thanked for their assistance with processing and databasing the material collected during SANSA. Members of the Spider Club and the SANSA volunteers (Linda Wiese, Helen Lieben, Victor Hamilton-Attwell, Elton le Roux, Walter Jubber, Renata Kruyswijk and the late Zanie van der Walt), reserve managers, and all the students from the universities of Stellenbosch, Rhodes, Cape Town, the Free State and Venda are thanked for their assistance with surveys and providing material. The contribution of photographers submitting images to the virtual museums is also acknowledged.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

 NOTES ON CONTRIBUTORS

A.S.D. identified specimens, processed species records and data, and wrote part of the manuscript; C.R.H. identified specimens, prepared figure plates, analysed data and wrote part of the manuscript; S.H.F. analysed data and prepared the map; L.N.L. identified specimens and helped with data analysis. All authors assisted with the conservation assessments and editing the final manuscript.