Maratus cuspis, Otto & Hill, 2019

Otto, Jürgen C. & Hill, David E., 2019, Three new peacock spiders from the southeast and southwest of Australia (Araneae: Salticidae: Euophryini: Maratus), Peckhamia 189 (1), pp. 1-77 : 2-29

Maratus cuspis , new species

Type specimens. The holotype male (♂ #1), 15 paratype males (♂ #2-16), and 7 paratype females (♀ #1- 7) were collected at Mount Frankland National Park, approximately 28 km NE of Walpole in Western Australia (S34.824326°, E116.969961°, 7 NOV 2018, coll. Jürgen C. Otto). All types will be deposited in the Western Australian Museum , Perth .

Etymology. The species group name ( cuspis, Latin , f., noun, English translation spear, is a reference to the outline of a spear point on the dorsal opisthosoma of the adult male.

Diagnosis. Maratus cuspis resembles the other two species of the linnaei group, all from the southwestern corner of Australia ( Figure 2 ). Although dark and lower in contrast, males have a middorsal figure comprised of branching lines ("evergreen tree pattern") like that of M. linnaei Waldock 2008 . The male opisthosoma is more tapered than in that species, sharply truncated rather than rounded at the rear. The opisthosoma of M. electricus Otto & Hill 2017a is cylindrical and not tapered, lacking a middorsal figure.

Description of male ( Figures 2 :1, 3-6). Adult males are 3.8-4.3 mm in length (n=16). The chelicerae are black and glabrous. The carapace is black, with a band of white to off-white or light brown setae covering the clypeus and extending under each AME and then between the AME and ALE on each side to form a distinct line extending across the eye region to the rear. Other than these two light bands, the eye region is covered with orange scales. On each side the carapace is covered with many irregular off-white setae, and a distinct lateral marginal band of white or off-white setae is present. To the rear of the eye region the carapace is mostly black to dark brown and glabrous. A thin middorsal line of white scales may be present in the thoracic region.

The opisthosoma (fan) is rounded or ovate anteriorly, tapering rapidly toward the rear where it is sharply truncated. The fan is decorated at the median with a dark, spear-shaped area pointed toward the rear, and within this area a less distinct outline of a dark "tree" pattern can be seen. On each side the fan is decorated with a series of curved bands of red to red-orange scales, separated by iridescent blue to bluegreen scales. Below the fan and above the spinnerets a small triangular tuft of white setae is present. The spinnerets are grey. Below, the opisthosoma is covered with off-white setae.

Legs I and II are shorter, legs IV longer, and legs III by far the longest. All legs are covered with long offwhite to light orange setae. Legs I and II may be indistinctly banded, legs IV more distinctly banded. Very long setae project ventrally from the patella to metatarsus of each leg III. Long and darker, dark orange to black setae project dorsally from the tibia to metatarsus of each leg III. There are scattered off-white setae on the tarsus of leg III, but these are not brightly coloured as in many other Maratus species.

The pedipalps are covered dorsally with long off-white or light brown setae. When extended to the front each pedipalp extends the line of light-coloured setae that crosses the respective side of the eye region ( Figure 3 :1). The RTA, tegulum and embolus (Figure 6) are unremarkable and compare closely with those of other species in the linnaei , vespa and other Maratus groups in southwestern Australia. Both outer and inner apices of the embolus are heavy and black, and as in related species there is a distinct projection near the distal end of the outer apex (Figure 6:28).

Description of female ( Figures 7-10 ). Adult females are 4.7-5.4 mm in length (n=7). The chelicerae are brown, translucent and glabrous. Long off-white setae extend from the clypeus over the proximal end of each paturon. The carapace is generally dark brown. There is a cover of off-white to brown setae over much of the carapace, including the eye region and the sides. The PME are closer to the PLE than to the ALE. There may be scattered off-white setae along each lateral margin of the carapace.

The opisthosoma, like the carapace, is generally dark brown with a cover of off-white to brown setae. Distinguishing patterns are present on the dorsal opisthosoma, but these are subtle and specimens should be compared closely with the photographs shown here. These include a small central white to offwhite spot behind two brown chevrons. Some individuals have distinct, broad marginal bands of offwhite to light brown setae. A small triangular tuft of white setae is present above the grey spinnerets. The underside of the opisthosoma is covered with off-white setae and irregular rows of small brown spots (mottling). The coxae, sternum, labium and endites are all translucent brown, with longer off-white setae projecting from the rear margin of the sternum.

Legs and pedipalps are uniform brown with regular to irregular segmental bands of off-white setae. Legs I and II are the shortest, legs IV longer, and legs III longest but close to legs IV in length. The epigynum ( Figure 10 ) is typical for the group and of little use for identification, with a large posterior spermatheca behind each fossa, and darker, sclerotized ducts visible through the posterior part of each fossa.

Courtship ( Figures 11-14 ). As with other members of the linnaei and vespa groups, females faced and approached courting males to closely observe each of their movements at a distance of only 2-4 millimeters ( Figure 11 ). The male display included two different stages. In the first stage ( Figure 13 :1- 17) the male centered his elevated fan in a symmetrical position behind legs III, with fully extended legs III in a vertical position with the tarsi in contact at the median. This transitioned to a second stage in which legs III were moved into a bracketing position to reveal more of the fan at the center, and the fan was moved from left to right or vice versa ( Figure 13 :18-50). Each time that the fan was rotated up toward a centered position it was moved very slowly but steadily through each of a series of very low amplitude (several degrees) increments. A change in the direction of fan rotation was initiated with a very rapid (<0.04s, blurred in a single frame at 25 FPS) lateral kick and partial return to center of one leg III in the new direction (indicated by arrow in Figures 13 :18,33). When the fan was lowered toward one side or the other, however, movement was more complicated, combining incremental movement toward that side with low amplitude up and down bobbing of the opisthosoma at ~9 cycles/s ( Figure 14 ).

Habitat and distribution. The types for this species were found at Mount Frankland National Park ( Figures 1 , 15 ). One male of this species was photographed but not collected near the Denmark-Mount Barker Road at Mount Lindesay National Park in Western Australia (15 OCT 2018, Jim Murray; Murray 2018) .

Figures

Figure 1. Localities associated with three new species of Maratus in Australia.

Figure 2. Adult males representing the three Maratus species placed in the linnaei group. Note the dark middorsal figure and posterior truncation of the tapered opisthosoma (fan) of M. cuspis (1).

Figure 3 (continued on next page). Living adult male types for Maratus cuspis.

Figure 7 (continued on next page). Living adult female types for Maratus cuspis.

Figure 8. Ventral views of living adult female types for Maratus cuspis.

Figure 9 (continued from previous page). Adult female type specimens for Maratus cuspis in ethanol.

Figure 10. Ventral views of the epigynum of adult female type specimens for Maratus cuspis in ethanol.

Figure 11. Selected frames from a 25 FPS video showing a female Maratus cuspis (at left) advancing toward a displaying male. The small white square is a reference position to show forward movement of this female as the male retreated to the rear.

Figure 12 (continued on next page). Positions assumed during courtship display by living male types for Maratus cuspis.

Figure 13 (continued on next page). Selected frames from a 25 FPS video of courtship display by a male Maratus cuspis directly in front of a female. Except for indicated stops, and rapid kicks to the side at the onset of fan rotation (18, 33) movement was continuous but only smooth when the fan was rotated toward a center position.

Figure 14. Video analysis of sequential frames during rotation of the fan to one side (25 FPS). The position of the fan in individual frames between positions (47) and (48) as shown in Figure 13 is shown here. In 39 frames (1.56s) there were 14 lo amplitude up/down cycles (bobs) of the opisthosoma, a rate of 9/s. This bobbing was superimposed on a slow and discontinuous rotation of the fan toward the spider's right side (red circles), and low-amplitude twisting of the fan. Toward the end of this sequence the twisting movement synchronized and alternated with each cycle of up/down bobbing, at 9/s. In contrast each increment of rotation of the fan back toward a vertical position was slow but continuous without low-amplitude bobbing or twisting.

Figure 15. Habitat of Maratus cuspis at Mount Frankland National Park in Western Australia.