Maratus sylvestris, 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 : 53-69

Maratus sylvestris , new species

Type specimens. The holotype male (♂ #1), 1 paratype male (♂ #2), and 2 paratype females (♀ #1-2) were collected in wet sclerophyll forest at Macquarie Pass National Park near Mount Murray in New South Wales (S34.54718°, E150.65387°, coll. Thomas Sayers). 1 paratype male (♂ #3) and 1 paratype female (♀ #3) were collected at Lady Fuller Park in Thirroul in a mixture of rainforest and wet sclerophyll forest (S34.30791°, E150.91338°, 24 NOV 2016, coll. Richard Jones). 4 paratype males (♂ #4-7) were collected at Tuckers Knob , Bindarri National Park in New South Wales (S30.32669722°, E152.942094°, 600 m elevation, 29 OCT 2016, coll. Jonas Bellchambers and Charlotte Miller). All types will be deposited in the Australian Museum, Sydney .

Etymology. The species group name ( sylvestris, Latin , adjective, English translation of the forest) refers to the fact that this species lives in forested areas.

Diagnosis. Maratus sylvestris can be identified as a member of the pavonis group by its detailed genitalic structure as well as its general appearance and colouration. Compared to the most closely related species in that group ( Figure 31 ), M. sylvestris males have a distinctive pair of broad red stripes across the eye region on a background of lighter brown setae, light, translucent and unbanded legs, and relatively long legs III, but lack a distinct red-orange central figure ("butterfly") on the fan. Unlike some members of the group, M. sylvestris males lack opisthosomal flaps but nonetheless flatten and expand the fan when it is elevated during courtship display. There are number of local forms of the related M. pavonis that need study ( Figure 31 :2-4), but in the east these have distinctly banded legs quite unlike those of M. sylvestris .

Description of male ( Figures 31 :6, 32-35). Adult males are 3.7-4.3 mm in length (n=7). The chelicerae are black and glabrous. White setae extend medially from the clypeus over the proximal chelicerae. The eye region is covered with light brown scales, interrupted by a wide band of red scales behind each AME. The PME are closer to the PLE than to the ALE. To the sides and rear the carapace is mostly black and glabrous. If not rubbed off, a wide brown to white mediothoracic band may be present. There is a welldefined white marginal band on either side of the carapace.

The opisthosoma is ovate without flaps, with prominent red-orange parens bracketing the center which is mostly covered with light brown scales. Around the parens there is a background cover of iridescent blue-green scales. Some red-orange scale patches may be present near the centre of the fan. These can be seen in the southern males ( Figure 32 :1-25) but are absent in the northern males ( Figure 32 :26-36). In any case there is no distinct "butterfly" pattern at the centre. There is a small triangular tuft of white setae above the spinnerets. The underside of the opisthosoma is brown with darker mottling, but with relatively few setae. The coxae, sternum, labium and endites are brown to gray and mostly glabrous.

Legs I and II are shorter, legs IV longer, and legs III by far the longest. Legs I, II and IV are brown to dark brown and transparent with few setae and little banding. Legs III are darker with long fringes of dark setae on the dorsal and ventral sides of each tibia and metatarsus. The tarsi of legs III are covered with thick white setae, and the setae of the underlying footpads are grey. The pedipalps are covered with bright white setae above and in front. Three dark, sclerotized apices of each embolus may be visible in lateral views of the pedipalp. The outer two apices are close together and their separation may not be evident.

Description of females ( Figures 36-39 ). Adult females are 4.8-5.8 mm in length (n=3). The chelicerae are glabrous and brown. White to off-white setae extend medially from the clypeus and surround the lower half of each AME. Dull red-orange scales are present above the AME and extend around either side near the lateral eyes. Otherwise the eye region is dark brown and glabrous. The PME are closer to the PLE than to the ALE. A narrow off-white mediothoracic stripe is present. Otherwise the sides and rear of the carapace are dark brown, translucent and glabrous.

The dorsal opisthosoma is dark brown with a row of lighter spots on either side of the midline and around each lateral margin. In some individuals these spots merge to form a series of three forwardpointing chevrons toward the rear. The underside of the opisthosoma is also dark brown. The coxae, sternum, labium and endites are all lighter brown, translucent and glabrous.

Legs I and II are the shortest, legs III and IV longer. All legs and the pedipalps are uniform brown in color and translucent with some scattered, off-white setae. There is no banding. The epigynum ( Figure 39 ) is unremarkable, with a large posterior spermatheca behind each large fossa, and darker, sclerotized ducts visible behind the posterior part of each fossa.

Courtship ( Figures 40-46 ). The courtship display of male Maratus sylvestris is very much like that of other members of the pavonis group, including M. pavonis and M. splendens ( Hill & Otto 2011) . For the present study we have been able to resolve respective movements at a much higher rate of speed (180 FPS). These spiders frequently wave one or two legs III as an apparent advertisement to draw the attention of females in the vicinity. There are three distinct modes of courtship display. Only the first of these (fan dance, Figures 41-42 ) includes display of the elevated fan between the fully extended legs III, held in a Vshape. In this display the fan is bobbed up and down through a small amplitude in a partly elevated position at a variable speed, observed at 16-66 cycles/s. This low amplitude movement includes slow side-stepping and waving of legs III at the tibiometatarsal joint, with the pedipalps held in position in front, concealing the chelicerae. In the second display mode (semaphore, Figures 43-44 ), usually seen just before the third display mode begins, extended legs III are brought rapidly to a vertical position and then bilaterally lowered to a horizontal position at the sides over the course of about 0.4-0.5s. The third mode of display (lunge, Figures 45-46 ) includes very rapid (observed at 23-28 cycles/s) and almost continuous back-and-forth movement of the entire body and legs III. Each cycle of this display is interrupted briefly at each front (advance) and rear (retreat) position. This is the final phase of approach before mating.

. Habitat and distribution ( Figures 1 , 47 ). The occurrence of Maratus sylvestris in rainforest and wet sclerophyll forest is unusual for the genus. In addition to the type localities of record, this species has also been observed at Oakes State Forest in New South Wales in a similar habitat (pers. comm., Jonas Bellchambers & Charlotte Miller), and it should be found at other wet forest locations along the southeastern coast of Australia in the future .

Figures

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

Figure 31. Comparison of (6) Maratus sylvestris to related species in the pavonis group. These include (1) M. literatus Otto & Hill 2014, (2-4) M. pavonis (Dunn 1947) and (5) M. splendens (Rainbow 1896).

Figure 32 (continued on next page). Male types for Maratus sylvestris.

Figure 36 (continued on next page). Living female types for Maratus sylvestris.

Figure 38 (continued on next page). Female type specimens for Maratus sylvestris in ethanol.

Figure 39. Epigynum of three female type specimens for Maratus sylvestris in ethanol.

Figure 40 (continued on next page). Display by male types for Maratus sylvestris in the laboratory. 3-4, Note movement of pedipalps as legs III were lowered in this intermediate fan dance/semaphore display. 8-9, Unilateral leg wave (advertisement).

Figure 41. Sequential high speed (180 FPS) video frames showing the fan dance of a male Maratus sylvestris. Arrows identify low amplitude movement of the fan, legs III and the entire side-stepping spider during this almost continuous movement. Movement was interrupted between frames (15) and (16). The opisthosoma was bobbed at ~16 cycles/s.

Figure 42. Sequential high speed (180 FPS) video frames showing the fan dance of a male Maratus sylvestris. Here the opisthosoma was bobbed up at down at a high speed (~66 cycles/s). 19-25, Flexion of the RIII metatarsus.

Figure 43. Three high speed video frames (180 FPS) showing steady, bilaterally symmetrical lowering of extended legs III over 0.422s during semaphore display by a male Maratus sylvestris.

Figure 44. Selected high speed video frames (180 FPS) showing rapid elevated of legs III to a vertical position followed by slower movement down to a horizontal position during the semaphore display of a male Maratus sylvestris. 4-15, Note intermittent low amplitude movement of the extended legs III (arrows).

Figure 45 (continued on next page). Selected video frames (180 FPS) showing alternating forward and rearward positions (~28 cycles/s) of a lunging male Maratus sylvestris in front of a female.

Figure 46 (continued on next page). Selected video frames (180 FPS) showing alternating forward and rearward positions (~23 cycles/s) of a lunging male Maratus sylvestris in front of a female.

Figure 47. Habitat of Maratus sylvestris. 1-2, Mixture of rainforest and wet sclerophyll forst at Lady Fuller Park in Thirroul. Photographs by Richard Jones. 3-5, Wet sclerophyll forest at Macquarie Pass National Park near Mount Murray in New South Wales. This is the designated type locality. Photographs by Thomas Sayers.