Asemonea stella

Asemonea stella is an African jumping spider that was first described by Fred Wanless in 1980.[1] He allocated the species to the genus Asemonea, first raised by Octavius Pickard-Cambridge in 1869.[2] The genus is related to Lyssomanes.[3] Molecular analysis demonstrates that the genus is similar to Goleba and Pandisus.[4] In Wayne Maddison's 2015 study of spider phylogenetic classification, the genus Asemonea was the type genus for the subfamily Asemoneinae.[5] A year later, in 2016, Jerzy Prószyński named it as the type genus for the Asemoneines group of genera, which was also named after the genus.[6]

The spider is small. The male is approximately 3.16 mm (0.124 in) long. It has a yellow carapace that is typically 1.44 mm (0.057 in) long and 1.13 mm (0.044 in) wide. It is pale to the back and tends to whitish-yellow near the eye field, which is black and a fringe of white hairs. The clypeus is pale yellow and shiny. The spider also has a pale yellow labium and sternum. The abdomen is also whitish yellow and shiny, but with a distinctive black star and two black patches on its back. The underside is whitish yellow with black patch near the epigyne. It has a length between 1.28 and 1.76 mm (0.050 and 0.069 in). The spinnerets are black with a fringe of dark brown hairs. It has an elongate posterior with a moderately long terminal article and a black anal tubercle. The legs are pale yellow with patches of black. The copulatory organs help differentiate the species, particularly from the related Asemonea pulchra. The palpal bulb has a furrow on the femoral apophysis and lacks the flange on the tegulum of other species.[7] Examples in South Africa have a pale green tint that enable them to blend into their habitat.[8]

The female is between 3.1 and 3.64 mm (0.122 and 0.143 in) long. It has a carapace that is between 1.28 and 1.46 mm (0.050 and 0.057 in) and between 0.85 and 1.1 mm (0.033 and 0.043 in) wide.[9][10] It is pear-shaped and light green with two parallel black lines. It has an eye field with four rows of eyes, as is typical for Lyssomaninae spiders, mounted on tubercles and surrounded by black rings. The middle eyes are relatively large. Its mouthparts and sternum are pale. It has chelicerae with three or five very small teeth at the front and four or seven to the back. The abdomen has a similar star-shaped pattern to the male, but black on a whitish background, and a light underside. It is typically 2.0 mm (0.079 in) long and 1.2 mm (0.047 in) wide; The spinnerets are white, The legs are long and thin, light with black spots and numerous long pale spines. The last pair of legs are the longest. The epigyne has small depression to the rear.[11] The seminal ducts are initially narrow, leading to spherical spermathecae. The spider has evident accessory glands.[12] As with the male, distinguishing the species from others in the genus relies on comparing the copulatory organs. The presence of a shallow depression in the middle of epigyne and the small chambers at the start of the seminal duct are distinctive for Asemonea stella.[10]

Despite being termed jumping spiders, Asemonea spiders rarely jump. Instead, they generally walk and run. They spin sheet webs on the underside of leaves, where they also lay their eggs.[13][14] Although predominantly a diurnal hunter, the spider is also likely to eat nectar if it is available.[15][16] It uses visual displays during courtship and transmits vibratory signals through silk to communicate to other spiders.[17]

Asemonea stella can be found in Kenya, South Africa and Tanzania, as well as Australia where it has been introduced.[1] The male holotype was found in a garden in the Kenyan coastal town of Kilifi in 1977. A female paratype was discovered close by in 1974, in hedge in open farmland about 200 m (660 ft) from the sea.[9] The first examples from Tanzania were a female first found in 1995 in a pitfall trap in scrub of Dichrostachys plants and a male discovered amongst grass in Senegalia senegal woodland in 1996.[18] The spider was first identified in South Africa based on a specimen from the eastern shore of Shokwe Pan in the Ndumo Game Reserve collected in 2000, which demonstrated that the species thrives amongst semiaquatic vegetation.[11]

Spiders, like Asemonea stella, can be transported by global trade networks over vast distances. As they are smaller than vertebrates, the spiders are less likely to be intentional travellers, usually travel as hitchhikers as part of the global trade in goods.[19] As global trade has increased, so the number of introduced species has increased, not just in numbers but in distance travelled.[20] Asemonea stella is one of those that has expanded beyond its natural habitat. The spider was found near Darwin, Australia, in 1965, the first example found in the country and the first time this spider has been found outside Africa.[10]