Genus: Hadogenes (flat rock scorpions)

Life > Eukaryotes > Opisthokonta > Metazoa (animals) > Bilateria > Ecdysozoa > Panarthropoda > Tritocerebra > Arthropoda > Arachnomorpha > Cheliceriformes > Chelicerata > Euchelicerata > Arachnida > Scorpiones (scorpions) > Superfamily: Scorpionoidea > Family: Liochelidae 

Hadogenes is a southern African endemic (occurs nowhere else) with species occurring in South Africa, Namibia, Botswana, Zimbabwe and Mozambique. There are currently 18 described species with more in preparation.

Hadogenes is lithophilous occurring in rocky habitats, retreating into rock crevices or under exfoliated rock. Their feet are adapted with special claws on the tarsus to enable it to grip and climb over its rocky habitat. Hadogenes is very habitat specific occurring in hot arid rock outcrops and, being unable to navigate over open stretches of sand, tends to speciate. Different species can often be found on different outcrops within 2 kilometres of each other. Experiments have illustrated that if a Hadogenes is moved more than 10 metres from its habitat it takes a few days to return. If the translocation is less than 7,5 metres it will return that same night. If the sand to be crossed is too extensive it will perish in the heat.

Hadogenes is dark brown and the legs are lighter in colour. The body and chelae are extremely flattened dorsoventrally and the legs and very thin tail are flattened laterally The tail and legs are of a similar thickness, the legs being weak and rarely used. The tail length is 60% to 200% of the trunk (combined prosoma and mesosoma). They vary in size from the small Hadogenes lawrenci (50 mm) to Hadogenes troglodytes, the world’s longest scorpion that attains a body length of 210 mm, and weighing up to 32 grams.

Hadogenes is threatened in certain areas due to habitat destruction for the quarry stone industry, urban development and the collection for the international pet trade. Two species, H. troglodytes and H. granulatus, are currently available in the pet trade. Fortunately those species occurring in conservation areas are offered greater protection.

Species indigenous to southern Africa

Two of the 15 species are featured below plus one unidentified species.

Hadogenes minor The only species in the Western Cape occurring in the Cedarberg. This scorpions future is secure as most of the greater Cedarberg will soon be protected in a very extensive conservancy streatching from the west coast to the Tankwa National Park in the east and northwards to Oorlogskloof Nature Reserve at Nieuwoudtville in the Northern Cape.
Hadogenes gracilis This scorpion has a very restricted range among some rocky outcrops in Mapumalanga and is threatened with extinction because of mining destroying its habitat.
Hadogenes sp.

Text by Norman Larsen ©