Maratus sapphirus, Otto & Hill, 2017

Otto, Jürgen C. & Hill, David E., 2017, Two new peacock spiders from southeastern Australia (Araneae: Salticidae: Euophryini: Maratus Karsch 1878), Peckhamia 153 (1), pp. 1-34 : 17-30

Maratus sapphirus , new species

Type specimens. The holotype male (♂ #1), 2 paratype males (♂ #2-3), and 1 paratype female (♀ #1) were collected near Bermagui, New South Wales at the edge of Murrah Flora Reserves and the Four Winds Music Centre at Barraga Bay (36.502472°S, 150.041944°E, 11:00, 12 NOV 2016, coll. H. Ransom, S. Harris, J. Morgan and D. Deans). All types will be deposited in the Australian Museum, Sydney .

Etymology. The species group name ( sapphirus , m., noun in apposition, English translation sapphire) refers to the sapphire-like appearance of the scale tract that decorates each lateral flap of the male fan, as well as the type locality on what is known as the Sapphire Coast of New South Wales.

Diagnosis. Male Maratus sapphirus most closely resemble M. vespertilio (Simon 1901; see also Otto & Hill 2011a, 2011b), and we place both species in a clade that we call the vespertilio group. However, there are distinct differences between the two species including the more distinct pattern of lines across the fan of M. sapphirus and the ornamentation of legs III in M. vespertilio ( Figure 19 ). The female of M. vespertilio has not been described, but like the female M. sapphirus has adjacent dark and off-white bands at the posterior opisthosoma.

Description of male ( Figures 20 -24). Males are 4.7-5.0 mm in length (n=3).

The carapace including clypeus, and the chelicerae, are generally black. Long white setae extend below the anterior eye row in a ventromedial direction. The eye region is partly covered with scattered offwhite to light brown scales, interrupted by an indistinct black figure where these scales are absent ( Figure 22 :2). Behind the eye region is a broad band comprised of off-white to light brown scales, projecting rearward to a point at the midline. Behind this and on the sides the carapace is mostly black and glabrous, except for scattered white to off-white setae and a well-defined but narrow off-white to white marginal band on either side. The PME are closer to the PLE than to the ALE.

The dorsal opisthosomal plate (fan) has well-defined lobate flaps that are usually wrapped around the sides of the opisthosoma, but can be extended during display ( Figure 21 :6,11-12). When these flaps are extended the fan is much wider than long. A wide marginal band of off-white or light brown scales is present at the front of the fan, interrupted by a black line at the midline. Behind this the central part of the fan is traversed by three black chevrons and a wide black area behind these, on a background of mostly iridescent blue-grey scales mixed with scattered off-white or red-brown pigmented scales. The anterior chevron is outlined by off-white scales. A narrow band of off-white setae occupies the rear margin of the fan. Each lateral flap is covered with a tightly-packed and very regular array of iridescent blue scales, and a large black spot occupies the front half of each flap. A small colular tuft of white setae is present above the grey spinnerets. The underside of the opisthosoma is generally brown with a cover of off-white setae. From below the legs and sternum are generally dark brown or black with scattered offwhite setae, and the labium, endites and pedipalps are brown ( Figure 20 ).

From above the legs are dark brown or black and indistinctly banded with a cover of off-white to brown setae interrupted by segmental rings of exposed black cuticle. Legs I and II are shorter, legs III and IV longer, and legs III are the longest.

The pedipalps are brown but covered dorsally (in front) with long off-white to white setae ( Figure 22 :5). Unlike most Maratus species where these are contiguous, the larger and longer outer apex is distinctly separated from the smaller and shorter inner apex of the embolus (Figure 24).

Description of female ( Figures 25-26 ). The paratype female is 5.7 mm in length.

The clypeus and chelicerae are mostly black and glabrous, except for long off-white setae extending ventromedially below the anterior eyes and scattered white setae on the medial side of each paturon ( Figure 25 :2). As in the male, the cuticle of the carapace is black. The eye region is covered with off-white or light brown scales or setae and this cover extends behind the PLE. Behind this there is a short median tract of light brown scales, but the posterior declivity of the carapace is black and glabrous.

The sides of the carapace are covered with scattered off-white to light brown scales. Unlike most female Maratus , a distinct marginal band comprised of off-white scales is present. The PME are closer to the PLE than to the ALE.

The dorsal opisthosoma has many long off-white or light brown setae extending forward from the anterior margin, but as in the male this is interrupted by a black median line, narrowing toward the rear. The front 2/3 of the opisthosoma is black but uniformly covered with off-white to light brown scales or setae. Behind this is a wide black transverse band, and behind this is a wide band comprised of more densely packed, uniform off-white to light brown setae that is relatively light in colour ( Figure 25 :3). At the rear is a small tuft of off-white colular setae. The ventral opisthosoma is light brown interrupted by a series of parallel, indistinct grey or black lines where the cuticle is exposed ( Figure 26 :7). The underside of the legs and sternum is black with scattered white or off-white setae, and the labium and endites are dark brown.

The legs and pedipalps are dark brown with a cover of off-white or light brown setae, interrupted and indistinctly banded by segmental rings of dark, exposed cuticle. Legs I and II are shorter, legs III and IV are longer, and legs III are the longest. The fossae of the epigynum are large and kidney-shaped, in front of the much larger posterior spermathecae. Prominent sclerotized (darker) ducts extend anterolaterally from each spermatheca to occupy the posterior half of each fossa in a ventral view ( Figure 26 :6).

Immatures. Immature Maratus sapphirus resemble the adult female ( Figure 27 ). Courtship display ( Figures 28-30 ). Males made rapid but low amplitude (~1-8°/cycle) rotations of the elevated and expanded fan at variable intervals (from <0.5 to ~6 cycles/s) as they side-stepped in front of the female. Legs III were not elevated or waved during this display, and the pedipalps were not moved but held in place to the side of each exposed paturon.

Habitat ( Figure 31 ). Maratus sapphirus was found on or near the ground at a density of 1-2/m 2, in a Spotted Gum ( Corymbia maculata ) woodland with coastal understory at the edge of the Murrah Flora Reserves near the Four Winds Music Centre at Barraga Bay, New South Wales. This is an area of thick leaf litter that was last burned more than 10 years previously and shows minimal human impact, with abundant dappled light below ~60-70% canopy cover (S. Harris, pers. comm.).

Figures

Figure 19. Comparison of male Maratus sapphirus (1, 3, 4) with M. vespertilio (2, 5-8). The fan of M. sapphirus is decorated with more distinct transverse lines and the legs are uniform in colour. Legs III of M. vespertilio have dark brown femora that contrast with the off-white or light yellow distal segments that bear a heavy fringe of long white setae, a wider and more lobate fan, and distinct dark brown stripes across the eye region.

Figure 20. Ventral view of three living adult male Maratus sapphirus.

Figure 21. Two adult male Maratus sapphirus. 6, Elevated and expanded fan during courtship display. 11-12, Posterolateral views of the opisthosoma showing the folded right flap of the fan (dorsal opisthosomal plate) in front of the exposed brown, soft cuticle of the opisthosoma.

Figure 22. Two adult male Maratus sapphirus.

Figure 25. Paratype adult female (♀ #1) Maratus sapphirus.

Figure 26. Paratype adult female (♀ #1) Maratus sapphirus. 1-5, In alcohol showing loss of much of the pigment of the living animal. 6, Ventral view of epigynum. 7, Ventral view before preservation in alcohol.

Figure 27. Four immature Maratus sapphirus. Except for size, these closely resemble the adult female and have the same characteristic black and off-white bands at the rear of the opisthosoma.

Figure 28. Courtship display by two adult male Maratus sapphirus.

Figure 29. Sequential but not consecutive video frames (25 FPS) showing courtship display by a male Maratus sapphirus. Only frames that show movement relative to the preceding frame are included in this sequence. Arrows indicate low amplitude (~1-2°), rotation of the fan and side-stepping relative to each preceding frame.

Figure 30. Sequential but not consecutive video frames (25 FPS) showing courtship display by a male Maratus sapphirus. Only frames that show movement relative to the preceding frame are included in this sequence. Arrows indicate relatively low amplitude (~1-6°) rotation of the fan and side-stepping relative to each preceding frame. 19-22, These consecutive frames show rapid rotation of the fan to the left by 3-4° (19), followed by rotation to the right by ~8° (20-22), corresponding to a rate of ~6 cycles/s. However this movement was not regular and the interval between successive movements of the fan could exceed 1s (e.g., 1.4s elapsed between frames 11 and 12). As in the sequence shown in Figure 29, elevation of legs III and movement of the pedipalps were not observed in this display.

Figure 31. Understory habitat of Maratus sapphirus at the Murrah Flora Reserves at Barraga Bay, New South Wales (courtesy Stuart Harris).