Euophrys maseruensis

Euophrys maseruensis is a very small spider with a body divided into two main parts: a broad cephalothorax and an oval abdomen.^[13] The male has a cephalothorax that is typically 1.1 mm (0.04 in) long and 0.8 mm (0.03 in) wide, The carapace, the hard upper part of the cephalothorax, is dark brown with a very subtle, poorly-developed depression, or fovea in the middle. The eye field is black. The underside of the cephalothorax, or sternum, is brown. The spider's face, or clypeus, is low and dark with some white hairs visible on its surface. The mouthparts are brown and the chelicerae has two teeth at the front and one behind.^[5]

The spider's abdomen is an oval that is longer than its carapace, with a length of 1.2 mm (0.05 in), but has a similar width. The top is hairless and covered with a shiny brown scutum and the underside is dark. The spider has greyish spinnerets, while its legs and pedipalps are generally brown. The legs have fine hairs that are colourless.^[5]

The spider has distinctive copulatory organs. Only the male has been described, but this is sufficient to be able to show how the species differs from other Euophrys spiders.^[1] The palpal bulb is brown and bulbous, with a bulge to its base and a thin embolus that loops around as it emanates from its top. The palpal tibia has a very narrow, but not needle-shaped, protrusion, or tibial apophysis.^[14][15] The narrow tibial apophysis and large embolic disk are key to distinguishing the spider from related species like Euophrys recta.^[16] It is otherwise similar to other species in the genus, particularly the type species Euophrys frontalis, but differs in its shorter tibial apophysis and broader embolus, and particularly the way that the embolus loops on a slight angle rather than running straight up.^[5][17]

Euophrys spiders live across the world, although those found in North America may be accidental migrants and those in Central and South America misidentifications.^[18][19] In Africa, they are mainly found in the southern part of the continent.^[20] Euophrys maseruensis is endemic to Lesotho.^[1][21] Restricted to a very limited area of the country, the spider thrives in the forests of the afromontane.^[16][22] The holotype has been discovered in 1977 near Molimo-Nthuse living on a boulder in the middle of a stream.^[5]