Maratus gemmifer, Otto & Hill, 2017

Otto, Jürgen C. & Hill, David E., 2017, Five new peacock spiders from Western Australia (Araneae: Salticidae: Euophryini: Maratus Karsch 1878), Peckhamia 152 (1), pp. 1-97 : 49-56

Maratus gemmifer , new species

Type specimens. The holotype male (♂ #1), 3 paratype males (♂ #2-4), and 1 paratype female (♀ #1) were collected in Banksia woodland at Karnup Nature Reserve (32.371257°S, 115.827134°E, 8 SEP 2016, coll. D. Knowles). All types will be deposited in the Western Australian Museum, Perth .

Etymology. The species group name ( gemmifer, Latin , m., adjective, English translation bearing gems) refers to the presence of a bright, iridescent gem-like spot on each lateral flap of the male fan.

Diagnosis. Six other species in the mungaich group have a large central black patch on their fan: M. sarahae Waldock 2013 , M. karrie Waldock 2013 , M. mungaich Waldock 1995 , M. madelineae Waldock 2014 , M. melindae Waldock 2013 and M. hortorum Waldock 2014 . M. sarahae and M. karrie both have a wide central black patch on the fan with a blue transverse line at the center and a large black spot at the center of each flap, therefore cannot easily be confused with M. gemmifer . Maratus madelineae also can be easily distinguished from M. gemmifer by having the large unpaired black patch in a more posterior position. The differences between M. gemmifer and the remaining species are more subtle ( Figure 56 ). Maratus mungaich has a small black spot near the centre of each flap, bordered by another spot of bright, blue-white iridescent scales to the rear, whereas M. gemmifer lacks the small black spot and instead has a larger patch of blue-white iridescent scales in this position. Maratus melindae has no spots at all in that position. Maratus hortorum can be distinguished from M. gemmifer by having two blue spots within the central black patch, a feature that also distinguishes this species from all other species in the mungaich group. M. gemmifer may also be separated from M. melindae corus by its lack of a more pronounced dorsomedial white tract behind the eye region.

Description of male ( Figures 57-60 ). Males were 4.7-5.1 mm in length (n=4).

The clypeus is dark with long off-white setae projecting forward near the median over the black, glabrous chelicerae. The eye region has a uniform, dense cover of dark orange or red-brown scales. Behind this the carapace is mostly black and glabrous except for the presence of scattered white to off-white scales along a middorsal tract that may extend half-way from the eye region to the rear of the carapace. The sides of the carapace are black and glabrous except for a narrow marginal band of white scales along each side. The PME are closer to the PLE than to the ALE.

The pattern of scales that cover the dorsum of the large fan of M. gemmifer resembles that of other members of the mungaich group with respect to the presence of figures comprised of red or orange pigmented scales on a background of blue to blue-green iridescent scales, but also has distinctive features identified previously in the diagnosis ( Figure 56 ). Notably these include the presence of red scales that border the posterior and lateral margins of the central black area of the fan, a relatively large blue spot behind the center of that black area, and a small bright spot of blue-white iridescent scales at the center of each flap. The fan is moderately fringed with black setae, particularly along the anterior margin. The large flaps are black on the underside ( Figure 57 :6).

Below, the opisthosoma is light-brown to brown with a cover of many white to off-white setae ( Figure 57 :6, Figure 60 ). White setae surround the black spinnerets. The sternum and labium are black. The coxae and trochanters of the legs are grey or light brown and mostly translucent, covered with many scattered white setae. Legs I and II are shorter than legs III and IV, and legs III are by far the longest. Legs I, II, and IV are brown with a cover of white scales and other setae. Viewed from the front, legs III are decorated with long white setae along most of the length of each femur and off-white to orange or gold setae from the distal femur to the patella and proximal tibia. The posterior side of each femur III is black and glabrous. The tibia and metatarsus of leg III are dark brown and bear dorsal and ventral fringes of long black setae. Each tarsus III is covered with long white setae that extend over the grey setae of the foot pad.

The dorsum of each pedipalp has a dense cover of long white setae. Below, the pedipalps are brown or dark brown. The pedipalp resembles that of many other Maratus species, with a shorter pointed apex behind a larger and longer pointed apex of the embolus (Figure 59).

Description of female ( Figures 61-62 ). The female paratype is 5.1 mm in length and quite unremarkable without obvious field marks to enable identification to species. The clypeus is light brown and translucent, bearing many long white to off-white setae directed ventromedially over the brown and mostly glabrous chelicerae. The eye region is covered almost uniformly with brown scales except for a dark brown line extending from the middle of the eye region to the rear. Behind the eye region the carapace is black and glabrous on either side of a central tract of off-white scales extending at least halfway to the rear margin. On each side of the carapace a wide band of brown to off-white scales and setae extends from the front to rear below the eyes, but below this the carapace is brown, glabrous, and translucent with no marginal band. The PME are slightly closer to the PLE than to the ALE.

The dorsum of the opisthosoma is dark brown with a cover of shorter brown to off-white scales, bordered by an indistinct black line on either side that separates this dark area from the off-white lateral margins and venter. The spinnerets are brown. Legs I and II are shorter and legs III are IV are longer, with legs III slightly longer than legs IV. Legs and pedipalps are brown and covered with scattered white to off-white scales and setae. The epigynum ( Figure 62 :6) is unremarkable, comprised of a pair of large nearly circular fossae anterior to a pair of large posterior spermathecae. Sclerotized ducts anterior to each spermatheca can be seen behind the posterior part of each fossa.

Female display. As previously reported for other Maratus species, this female reared her opisthosoma and extended her legs III in a display that appeared to represent rejection of a male in the vicinity ( Figure 61 :6-11).

Courtship display ( Figures 63-66 ). The display of Maratus gemmifer males is relatively simple but spectacular because of the large size of the fully extended fan. In a fixed position the male will face the female with legs III extended and partly flexed to cradle the elevated and expanded fan. In this position the fan is rotated quickly to one side through ~20°, then returned to a center position about 0.08s later ( Figures 65-66 ). About one second later the fan may be rotated quickly to the opposite side and then returned to the center in the same manner. When stepping from side to side in front of a female, a male may either hold the fan in place, or rotate it from left to right more quickly through a smaller amplitude (amplitude ~10°, rate 8-12/s). When side-stepping the leading leg is generally raised and the trailing leg is lowered. During this display the pedipalps are held in place in front of the chelicerae, and movement of the extended legs III is minimal.

Figures

Figure 56. Comparison of the extended fan of M. gemmifer with related members of the mungaich group. 1-3, M. gemmifer from the type locality at Karnup Nature Reserve. 4, M. melindae corus from the type locality for this subspecies at the Banksia Reserve (Verne Hill). 5, M. mungaich from Mt. Dale, 46 km ESE of Perth. 6, M. hortorum from Bungendore Park, 30 km SE of Perth.

Figure 57. Three adult male Maratus gemmifer. 1, 5, 7, Facing female with elevated and extended fan during courtship display. 6, Rear view of male with elevated fan showing extension of the pedicel.

Figure 58. Two adult male Maratus gemmifer preserved in alcohol.

Figure 60. Ventral view of three adult male Maratus gemmifer. The long flaps of the fan overlap when completely folded around the opisthosoma (1, 3).

Figure 61. Adult female Maratus gemmifer. 6-11, Elevation of opisthosoma and extension of legs III during display.

Figure 62. Adult female Maratus gemmifer preserved in alcohol.

Figure 63. Courtship display by two male Maratus gemmifer facing a female. Note the small spot of very bright, iridescent blue-white setae at the center of each lateral flap of the fan. Legs III are held in place to frame this display and all movement is associated with side to side rotation of the fan or side-stepping in front of a female.

Figure 64. Courtship display by a male Maratus gemmifer facing a female.

Figure 65. Sequential but not consecutive frames from a video (25 FPS) of courtship display by a male Maratus gemmifer facing a female. Arrows indicate rotation of the fan or side-stepping (16 only) relative to the preceding frame. Note rotation of the fan to one side (10) and return to a centered position (11), followed by rotation to the other side (13) and return to a centered position (14).

Figure 66. Sequential but not consecutive frames from a video (25 FPS) of courtship display by a male Maratus gemmifer facing a female. Arrows indicate rotation of the fan, movement of the extended legs III, or side-stepping relative to the preceding frame. When the male side-stepped in front of a female, the leading leg III was raised and the trailing leg III lowered as shown here (18-20).