Saratus, Otto & Hill, 2017

Otto, Jürgen C. & Hill, David E., 2017, Five new peacock spiders from eastern Australia (Araneae: Salticidae: Euophryini: Maratus Karsch 1878 and Saratus, new genus), Peckhamia 147 (1), pp. 1-86 : 70

Saratus , new genus

Type species. Saratus hesperus , new species

Etymology. Saratus (noun, m.) is a modification of the genus name Maratus , selected to reflect similarities between the two genera.

Description. This is a monotypic genus. Saratus is small (3-4 mm) and very similar to Maratus species with respect to the morphology, colouration and display behaviour of both males and females. Saratus , like Maratus , have shorter legs I and II and longer legs III and IV, with legs III the longest. However, male and female genitalia of Saratus are distinctly different from those of Maratus or related genera such as Jotus ( Otto & Hill 2016a) . The embolus of the pedipalp of each Maratus species is comprised of a relatively large and almost complete outer ring and usually a shorter ring segment that appears beneath this near the apex (e.g. M. neptunus , Figure 62 ). The visible embolus of Saratus is quite small in comparison, comprised of only a short, curved spike on top of a small sclerotized process ( Figure 84 ). Whereas the epigynum of Maratus species has a large and distinct fossa (window or fenestra) anterior to each large posterior spermatheca ( M. neptunus , Figure 68), the fossa of the Saratus epigynum, if visible, is just below or only slightly anterior to the large posterior spermatheca ( Figure 88 ). Because S. hesperus is so similar to Maratus in other respects, these differences in genitalia are surprising, particularly since little interspecific variation of the genitalia of Maratus is the norm. Comparison of DNA sequences may at some time suggest that Saratus should be treated as an aberrant Maratus , or at least a close relative of that genus. Emergent (second instar) Saratus have a distinctive pattern of eight black spots on the dorsal opisthosoma that disappear as they mature ( Figure 90 ), a feature that we have not seen in any Maratus .

Figures

Figure 62. Medial to lateral views of the left pedipalp of the holotype (1-4) and four paratype (5-8, 9-11, 12-15, 16-20) male Maratus neptunus.

Figure 84. Holotype (1-4 & 14) and three (5-8 & 15, 9-12 & 16, 13 & 17) paratype male Saratus hesperus fixed in alcohol.

Figure 88. Ventral view of three living female Saratus hesperus.

Figure 90. Three female Saratus hesperus fixed in alcohol (1-2 & 9, 3-4 & 11, 5-8 & 10).