Sahastata wesolowskae

Sahastata wesolowskae is a species of crevice weaver in the genus Sahastata that lives in Oman. It was first described in 2020 by Ivan Magalhaes, Mark Stockmann, Yuri Marusik and Sergei Zonstein. The spider is small, with a carapace that is between 1.67 and 3.36 mm long and an abdomen that is between 3.73 and 4.94 mm long. The female is larger than the male, darker in color and has a more rounded abdomen. Both have a V-shaped pattern towards the middle of the carapace, but it is clearer on the female. The male has a long and slightly bent embolus. The female has an endogyne with distinctive spermathecae. It is these copulatory organs that most clearly differentiate the species from other spiders in the genus.

Taxonomy
Sahastata wesolowskae was first described by Ivan Magalhaes, Mark Stockmann, Yuri Marusik and Sergei Zonstein in 2020. The species is named after the Polish arachnologist Wanda Wesołowska. It was placed in the genus Sahastata, raised by Pierre L.G. Benoit in 1968. The genus is a member of the subfamily Filistatinae in the family Filistatidae, which are known as crevice weaver spiders. The genus is related to Kukulcania, differing in details like the design of the second tarsal claw. The species is most related to Sahastata nigra, and then to Sahastata wunderlichi. DNA sequencing has also determined that it is closely related to Sahastata aravaensis.

Description
Sahastata wesolowskae is generally a medium to large spider, but examples vary greatly in size. The male has a total length that ranges between 3.32 and 5.98 mm while the female is larger between 8.17 and 15.3 mm long. The male is generally yellowish cream in color. The carapace, that is between 1.67 and 3.08 mm long and typically a 2.53 mm wide, is darker towards the eye field and has an indistinct V-shaped pattern towards the middle. The abdomen is typically 3.73 mm long and 1.87 mm wide. It is elongated, brown and hairy. The legs are brown and yellow. The chelicerae has a small front tooth. The palpal bulb has a femur that is about twice as long as the carapace and a cymbium twice as long as the palpal bulb. The embolus is long with a slightly bent end.

The female is generally light brown. The carapace, which has a clearer brown V-shaped pattern, is typically 3.36 mm long and 2.56 mm wide. The abdomen has a typical length of 4.94 mm long and 3.13 mm wide. The abdomen is larger and more rounded than the male, and has a pattern reminiscent of a river delta. The legs are generally brown with yellow ends. The endogyne has spermathecae that have an area shaped like a boomerang, surrounded by a long portion that has a membrane.

The spider can be distinguished from other spiders in the genus by its copulatory organs. The spider is similar to the related Sahastata nigra. The male differs in having a longer and more sinuous embolus that has distinctive ridges. The species can also be distinguished from Sahastata sinuspersica by the shape of the embolus. The structure of the epigyne differentiates the female from the other species.

Behaviour
As well as being resistant to extremes of temperature, Sahastata wesolowskae thrives in areas which lack water. The mainly get hydration via their prey. The females are less discriminatory on who they mate with than other species in the genus. They build their eggs three months after mating, each egg sac containing typically 169 juveniles. The juveniles are predominantly female, representing about 20 percent of the younger population. Although the males mature more quickly, the females also have a generally longer lifespan. After mating, the female will often eat the male in preference to other prey.

Distribution and habitat
The spider is endemic to Oman. The holotype was found near Salalah in the Dhofar Governorate in 2016. Other examples have been found in Al Wusta and near Thumrait. The examples are generally found in flat sandy environments that have limited vegetation. This is typical of the genus, which generally live far from human habitation. The spider can be negatively impacted by oil spills, its preferred habitats being particularly vulnerable to pollution.