Stenaelurillus mirabilis

Stenaelurillus mirabilis was first described by Wanda Wesołowska and Anthony Russell-Smith in 2000.[1] It is one of over 500 species identified by the Polish arachnologist Wesołowska.[2] It was placed in the genus Stenaelurillus, first raised by Eugène Simon in 1885.[3] The name relates to the genus name Aelurillus, which itself derives from the Greek word for cat, with the addition of a prefix meaning narrow.[4] The species name is a Latin word that can be translated wonderful.[5] In 2015, the genus was placed in the subtribe Aelurillina in the tribe Aelurillini in the clade Saltafresia by Wayne Maddison.[6] Two years later, it was grouped with nine other genera of jumping spiders under the name Aelurillines.[7]

The spider is medium-sized. The male has a dark brown pear-shaped carapace that measures between 1.75 and 1.9 mm (0.069 and 0.075 in) in length and between 1.33 and 1.4 mm (0.052 and 0.055 in) in width, with two long white stripes on the thorax and one wide white stripe along each edge. The abdomen is black and hairy, between 1.9 and 2.0 mm (0.075 and 0.079 in) long and 1.2 and 1.23 mm (0.047 and 0.048 in) wide, with a cross-shape formed of five white spots.The eye field is dark, nearly black, and has short protruding bristles. The spinnerets are long and white, and the legs are brown and yellow. The pedipalps are also brown and hairy.[8][5] It can be distinguished from other members of the genus by its long thin palpal bulb, which has a tubercle at the very end, and short embolus.[9]

The female is very similar to the male in colouration and shape, but is larger. The carapace is between 2.0 and 2.7 mm (0.079 and 0.106 in) long and 1.6 and 1.7 mm (0.063 and 0.067 in) wide and the abdomen between 2.3 and 2.8 in (58 and 71 mm) long and 1.7 and 1.9 mm (0.067 and 0.075 in) wide.[10] The carapace is also pear-shaped and dark brown, and has two white stripes on the thorax. The abdomen has a white stripe in the middle which stretches from the front to back, interrupted by two white marks in the middle and ends. The edges of the abdomen are orange and the lighter parts have an orange shine.[11] The spinnerets are yellow. The epigyne is small with a flat plate and the rear sclerotized, with widely separated copulatory openings. The insemination ducts are short and slightly bent toward each other and the spermathecae are round.[12] The conformation of both the epigyne and the spermathecae are particularly distinguishing for the species.[13] The lack of gonopores in the epigyne particularly distinguishes the species from the otherwise similar Stenaelurillus ignobilis.[14]

The holotype was found near the Ibaya camp in the Mkomazi National Park in 1993. Many other examples were found across the reserve, in a range of habitats including Acacia senegal woodland, Combretum bushland and grassland. [15] At the time, it was the most abundant ground-active salticid in the reserve.[16] It was also subsequently found in the forests of the Tsavo East National Park in the coastal regions of Kenya.[17]