Black-legged Burrowing Scorpion (Opistophthalmus fuscipes)

Mohamed bin Zayed Species project number 11252329

The southern African burrowing scorpion genus Opistophthalmus includes the world’s most threatened scorpions. Five species from the Western Cape Province of South Africa (Opistophthalmus fuscipes, O. intermedius, O. latro, O. leipoldti and O. capensis) are particularly at risk. Between 65% and 85% of the estimated extent of occurrence of these very range-restricted, habitat-specific scorpions has been transformed by agriculture (farming and afforestation), urbanization, mining and the creation of artificial waterbodies (dams and reservoirs). A continuing decline is observed, inferred and projected in the extent of occurrence, area of occupancy, the area, extent and quality of habitat, and the number of localities. A population size reduction of at least 80% is estimated, inferred and projected within the next three generations, based on a decline in the extent of occurrence, the area of occupancy and the quality of habitat, the causes of which (agriculture, urbanization, afforestation, and mining) have not ceased.

The conservation status of the five target species has not been formally established, because the number of existing populations remains to be ground-truthed. However, based on the limited distributional data available for the species, and the known extent of transformation of their habitat, three are probably Critically Endangered (O. fuscipes, O. intermedius and O. latro), one Endangered (O. leipoldti), and one Vulnerable or Endangered (O. capensis).

All five scorpion species are endemic to the Fynbos Biome, also known as the Cape Floral Kingdom, the smallest but richest, for its size, of the world’s six floral kingdoms. These scorpions are restricted to Renosterveld, Sand Plain Fynbos and Strandveld vegetation types, less than 2 % of which are conserved. They could serve as charismatic flagship invertebrate species to advertise the plight of South Africa’s Fynbos habitats in the international media. Their protection and continued existence will also provide shelter for other endangered plants and animals.

The project has the following objectives. The project will survey the historical distribution of these scorpions, identify where the remaining viable populations occur, and assess whether any fall within protected areas, using GIS-based analysis of the remaining patches of potentially suitable habitat (using existing spatial datasets of vegetation types), overlain by known distribution records for the species. This will be followed by ground-truthing: a field survey during which all potentially suitable habitat patches identified by GIS, especially those coinciding with historical records of these scorpions, will be visited. After the field survey is completed, the coordinate data for all known, remaining populations of these scorpions will be overlain with a spatial dataset of protected areas, again using GIS, and a gap analysis conducted to assess whether any populations are protected.

The third objective is to assess the population structure of these scorpions, in order to inform on decisions that are essential to their management and long-term survival. The genetic diversity among and within the remaining populations will be assessed, using DNA sequences from two variable mitochondrial gene loci and a variable nuclear gene locus. A nondestructive haemolymph (blood) sample will be taken from several individuals at each population.  A phylogeographic analysis of the sequences of generated from these samples will be used to determine the current genetic structure and the phylogeographic history of the species.

This study will be used to examine how many evolutionarily significant units exist within the remaining populations, which will assist future conservation efforts to save these species from impending extinction, by informing on conservation management decisions vital for any translocation attempts.

The final objective is to assess the conservation status of the five species by applying IUCN criteria using the data obtained and make recommendations to the provincial conservation authority. The combination of a field survey to identify the remaining populations of scorpions, the GIS gap analysis to assess if any populations are protected, and the genetic analysis of population structure will allow recommendations to be made regarding which species and population/s to prioritise for conservation.

For more details, visit http://scorpion.amnh.org