Sahastata wesolowskae

Sahastata wesolowskae was first described by Ivan Magalhaes, Mark Stockmann, Yuri Marusik and Sergei Zonstein in 2020.[1] The species is named after the Polish arachnologist Wanda Wesołowska.[2] It was placed in the genus Sahastata, raised by Pierre L.G. Benoit in 1968.[3] 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.[4] The species is most related to Sahastata nigra, and then to Sahastata wunderlichi.[5] DNA sequencing has also determined that it is closely related to Sahastata aravaensis.[6]

Sahastata wesolowskae is generally a medium to large spider,[4] but examples vary greatly in size. The male has a total length that ranges between 3.32 and 5.98 mm (0.131 and 0.235 in) while the female is larger between 8.17 and 15.3 mm (0.322 and 0.602 in) long. The male is generally yellowish cream in color. The carapace, that is between 1.67 and 3.08 mm (0.066 and 0.121 in) long and typically a 2.53 mm (0.100 in) wide, is darker towards the eye field and has an indistinct V-shaped pattern towards the middle. The abdomen is typically 3.73 mm (0.147 in) long and 1.87 mm (0.074 in) wide.[7] It is elongated, brown and hairy. The legs are brown and yellow.[8] The chelicerae has a small front tooth.[4] 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.[7]

The female is generally light brown. The carapace, which has a clearer brown V-shaped pattern, is typically 3.36 mm (0.132 in) long and 2.56 mm (0.101 in) wide. The abdomen has a typical length of 4.94 mm (0.194 in) long and 3.13 mm (0.123 in) wide.[7] The abdomen is larger and more rounded than the male, and has a pattern reminiscent of a river delta.[9] 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.[7]

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.[7]

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.[5] They build their eggs three months after mating, each egg sac containing typically 169 juveniles.[10] 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.[10]

The spider is endemic to Oman.[1] 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.[8] This is typical of the genus, which generally live far from human habitation.[3] The spider can be negatively impacted by oil spills, its preferred habitats being particularly vulnerable to pollution.[11]