Pachyballus castaneus

Pachyballus castaneus is a species of jumping spider that is native to South Africa and Zimbabwe. A member of the genus Pachyballus, the male of the species was first described in 1900 by Eugène Simon and the female in 2020 by Wanda Wesołowska, Galina Azarkina and Konrad Wiśniewski. The spider looks like a beetle, with a round cephalothorax that is between 0.9 and 1.4 mm (0.035 and 0.055 in) in length and a heart-shaped abdomen that is between 1.7 and 2.2 mm (0.067 and 0.087 in) in length. Externally, the spider is hard to distinguish from other spiders in the genus. It is generally dark brown on top while the abdomen is brownish-grey underneath with two scuta, the rear one shaped like a trapezium. Its copulatory organs are distinctive. The male has a thinner pedipalp and a more compact coiled embolus. The female has shorter insemination ducts that lack any loops.