Sicarius (six-eyed crab spiders, six-eyed sand spiders)
(animals) > Bilateria > Ecdysozoa > Panarthropoda > Tritocerebra >
Arthropoda > Arachnomorpha > Cheliceriformes > Chelicerata > Euchelicerata
> Arachnida > Araneae
> Araneomorpha > Family: Sicariidae
Sicarius, like Loxosceles (also in the Sicariidae), has 6 eyes arranged in 3 diads that are widely spaced in a recurved
row. The cuticle is leathery (coriaceous) with curved setae and is usually maroon or
yellow in colour. It is a robust, flattened spider, 9 - 19 mm long and a legspan of about
50 mm. The legs are laterally placed, resembling a crab, hence the common name.
Sicarius is a living fossil that pre-dates the Gondwanaland drift some 100
million years ago and also occurs in South America. There are 6 species distributed in the
Western Cape, Namibia and Northern Province. They occur in sand, on sand dunes, under
rocks and rock overhangs and generally in the vicinity of antlion pits. Sicarius
catches prey by hiding under the sand. It raises its body, digs a depession, drops
into it and then covers itself with sand using the front legs. The prey is caught using
the front legs when the prey runs over the concealed spider. If a Sicarius spider
is uncovered it will be covered with fine sand particles that adhere to cuticle acting as
an effective camouflage.
Silk is used only to make the cup-shaped egg sac that is constructed using a combination
of sand and silk. The egg sac remains buried and spiderlings develop slowly. Adults can
live as long as 15 years which is unusual as most aranaemorph spiders live for 1 to 3
years. Furthermore, a well nourished spider can live for a year without food or water.
Sicarius hahnii from the Northern Cape and Namibia is possibly the most lethal
spider in the world. Fortunately, due to its habitat, it is rarely encountered and appears
reluctant to bite. I have often scooped up a Sicarius by hand while looking for
reptiles. This spider should not be handled, as there is no effective treatment.