First Atlas of the Spiders of South Africa (Arachnida: Araneae).South African National Survey of Arachnida Technical Report 2010 version 1

The South African National Survey of Arachnida (SANSA) was initiated in 1997, with the
main aim of documenting the arachnid fauna of South Africa at a national level. The South
African National Biodiversity Institute (SANBI) came on board for the project’s second
phase, called SANSA II, from 2006 to 2010, in partnership with the Agricultural Research
Council (ARC).
This four-year inventory and conservation assessment project was dedicated to unifying
and strengthening biodiversity research on spiders, and other arachnid fauna of South
Africa. SANSA’s aims are multiple, and include the collation of data, to determine the distribution
ranges of species in South Africa, for assessing their Red List status, using the
IUCN criteria.
All available data were collated into a relational database and to maximize benefits it was
important to determine the spatial coverage of the already available data, and determine
where the ‘gaps’ in this data lie. Thus, field collecting can be guided towards filling these
gaps. Data that was available electronically formed the basis of a GIS based gap analysis
that was done end of 2007 to identify these gaps in spatial coverage for South African
arachnids. Based on the GAP analysis areas were identified to undertake SANSA surveys.
Due to extensive field work by SANSA field work managers and by catches of other
research projects, student projects and public participation in collecting specimens, more
than 40 degree squares were sampled in areas previously poorly sampled, providing valuable
material that improved our knowledge of the distribution of species and provided
specimens for future taxonomic studies. All these data was used to compile this first atlas
of the spider species of South Africa. Data included in this atlas will be used to assess
their Red Listing status.
Some of the results are:
• 70 families, 463 genera and 2003 species are presently known from South Africa.
• This represent 4.8% of the world’s fauna.
• Of the 2003 species 1220 (61%) are endemic to the region.
• With 485 species having a restricted distribution, known only from few localities
• In South Africa Salticidae is the most diverse family with 240 species, followed by
the Gnaphosidae with 176 species and Thomisidae with 133.
• Two families Chummidae and Pentastomidae is endemic to South Africa.
• During SANSA II a total of 116 new species were discovered and described and
another 50 is in the process of being described
• Distribution ranges of more than 200 species known from the rest of Africa were
extended to include South Africa.
• Information on habitat requirements showed that the Savanna Biome is the most
diverse with 1207 species from 62 families, followed by the Grassland Biome with
245 from 56 families.