Menemerus minshullae

Menemerus minshullae is a species of jumping spider in the genus Menemerus that lives in South Africa, Malawi and Zimbabwe. The species was first described in 1999 by Wanda Wesołowska, one of over 500 descriptions she has completed during her lifetime. She originally identified the male as a different species, named Menemerus manicus, but merged the two in 2007. It is small to medium-sized spider with a cephalothorax that is between 1.9 and 2.2 mm long and an abdomen between 2.1 and 3.3 mm long. The female is larger than the male and lighter, with a dark brown rather than black carapace and lighter brown abdomen. The abdomen has a large, leaf-shaped, pattern. It lives on Vachellia xanthophloea trees, using its flattened shape to hide under flakes of bark. The copulatory organs distinguish the species from others in the genus. The male has a very short embolus with a larger accompanying conductor. The female epigyne has two pockets that have strongly sclerotized edges.

Taxonomy
Menemerus minshullae is a species of jumping spider that was first described by the Polish arachnologist Wanda Wesołowska in 1999. She described two species, one named Menemerus minshullae and the other Menemerus manicus, but further discoveries led to the realisation that the two were simply the female and male respectively of the same species and so the two were combined under the current name. It is one of over 500 species identified by during her career, making her one of the most prolific in the field. She allocated the spider to the genus Menemerus. The genus was first described in 1868 by Eugène Simon and contains over 60 species. The genus name derives from two Greek words, meaning certainly and diurnal. The genus shares some characteristics with the genera Hypaeus and Pellenes.

Genetic analysis has shown that the genus is related to the genera Helvetia and Phintella. It was placed in the tribe Heliophaninae and then, when that tribe was renamed by Wayne Maddison in 2015, Chrysillini. The tribe is ubiquitous across most of the continents of the world. It is allocated to the subclade Saltafresia in the clade Salticoida. In 2016, Prószyński created a group of genera named Menemerines after the genus. The vast majority of the species in Menemerines are members of the genus, with additional examples from Kima and Leptorchestes. The species is named in honour of Jacqui Minshull, a curator of spiders at the Natural History Museum of Zimbabwe.

Description
Menemerus minshullae is a small to medium-sized spider. The male has a cephalothorax that is between 1.9 and 2.1 mm long while the female cephalothorax is between 2.0 and 2.2 mm long. Both are between 1.5 and 1.6 mm wide. The female has a dark brown carapace that is between 1.6 and 2.1 mm long and between 1.4 and 1.6 mm wide with white stripes formed of hairs on its edges. In some examples, there are four white patches on the thorax. The eye field is black, sometime with a metallic sheen, with occasional white hairs amongst the long brown hairs and brown bristles. The spider has a low clypeus that also has white hairs. The chelicerae, labium and sternum are dark brown;the maxilae are lighter, with white tips. The brownish or light brown abdomen is between 2.1 and 3.3 mm in length and between 1.5 and 2.4 mm in width. It has a large, leaf-shaped, lighter patch covering much of the topside and a pale underside that occasionally has a wide stripe down the middle. It has greyish-yellow spinnerets. The front legs are sometimes light brown, the remainder yellow, with thin brown hairs and spines visible on all of them. The epigyne is oval and strongly sclerotized with a single large pocket and two oval depressions. The copulatory openings lead to simple insemination ducts with accessory glands and small spermathecae.

The male's carapace is low and black with white lines formed of hairs on the edges. There is a light patch on the head that blends into a streak on the main body. There are white hairs on the eye field and brown bristles near the eyes. The spider has a very low clypeus that also has white hairs. The chelicerae are dark brown; the labium, maxilae and sternum are lighter. The elongated dark brown abdomen is between 2.2 and 2.5 mm long and 1.4 and 1.5 mm wide. It is covered in thin, translucent hairs with a similar large, leaf-shaped, fawn patch to the female. The underside is brown. It has greyish-brown spinnerets. The front legs are dark brown, the remainder lighter with dark stripes. They are covered in dense brown hairs. The pedipalp is brown with white hairs. There are also hairs on the base of the cymbium. The palpal bulb is oval with a wide furrow evident down the centre and a short embolus and a larger accompanying conductor that almost dominates it. The bulb has short bloated femur and a wide tibial apophysis, or appendage, which has a distinctive valley-like morphology.

Spiders of the Menemerus genus are difficult to distinguish. The copulatory organs help to identify Menemerus minshullae, particularly the strongly sclerotized edges to the two large oval depressions in the female epigyne. The male can be differentiated from other related spiders by its small embolus and conductor, and particularly its sclerotized end.

Distribution and habitat
Menemerus spiders are found throughout Africa and Asia, and have been identified as far as Latin America. Menemerus minshullae is found in South Africa, Malawi and Zimbabwe. The female holotype was found near Mutare, then called Umtali, in 1979. Other examples were found in Bulawayo in 1983 and 1989. It was subsequently also seen in the Sengwa Wildlife Research Area in 2001 and 2002. The first to be found in Malawi was collected in 1976 near Chintheche. The species range was expanded to South Africa when examples were identified in Ndumo Game Reserve between 2005 and 2007. The spider thrives in arboreal environments. It seems to be particularly fond of living on Vachellia xanthophloea, with the flattened shape of its body enabling it to hide under shards of bark that become loosened from the tree.