Maratus Fimbriatus Otto & Hill 2016

Otto, Ju. rgen C. & Hill, David E., 2022, Maratus ammophilus, a new peacock spider in the Fimbriatus group from Western Australia (Araneae: Salticidae: Euophryini), Peckhamia 273 (1), pp. 1-65 : 32-50

Maratus Fimbriatus Otto & Hill 2016

Maratus fimbriatus Otto & Hill 2016 , ♂ ♀

Maratus licunxini Baehr & Whyte 2016 , ♂ only, new synonym

Here we present a revised description of this species, as well as updated documentation of the male courtship display, including a comparison of populations in the interior of New South Wales and Queensland. Specimens collected in Queensland have previously been identified as Maratus licunxini . After a reexamination of the description and detailed photographs of type specimens for M. licunxini ( Figure 20 :1-7), as well as our study of a new male variety of this species from Queensland, we have determined that these forms all represent a single species, based in part on the variability of the scale patterns of the dorsal opisthosoma of the male ( Figures 20-21 ), but also on the close similarity of all other characters that we have examined.

The description of the male Maratus licunxini from Carnarvon QLD also included a chimney-like embolus opening at the prolateral part of the embolus as a diagnostic character for that species, with reference to an SEM image of the same (Baehr & Whyte 2016). However we consider this to represent a general feature for species in the fimbriatus group, and in all respects, including details of the colouration of setae, we can find no characters of the male pedipalp to distinguish M. licunxini from other forms of M. fimbriatus .

A single female paratype was also described for M. licunxini , based on collection at the type locality, with the qualification that conspecifity may be established when the courtship of this species is observed and the DNA is tested (Baehr & Whyte 2016, p. 508). The epigynum of this female is distinctly different from that of female M. fimbriatus from either New South Wales or Queensland, for which courtship and mating with males has been observed and documented. We consider this female specimen to represent an undetermined (or indeterminate) species .

New material examined. Two male (♂ #1-2) and one female (♀ #1) Maratus fimbriatus were collected about 75 km east of the type locality for M. licunxini , 14 km west of Rewan , Queensland (24.976330°S, 148.390200°E, 21 NOV 2021, coll. Donna and Laurence Sanders. All specimens will be deposited in the Queensland Museum, Brisbane.

Etymology. The species group name ( fimbriatus, Latin , m., adjective, English translation fringed) refers to the presence of a prominent fringe of long setae encircling the opisthosoma of the adult male (Otto & Hill 2016).

Diagnosis. The dorsal opisthosoma is encircled by a prominent fringe, and bears a variable series of white scale tracts in front, with the black, glabrous dorsal plate (scute) exposed to the rear. The inner and outer rings of the embolus of the male pedipalp are fused and shaped like a wheel rim, a characteristic shared with other members of the fimbriatus group. Legs I are elevated by the male, to display the dark brown or black/dark yellow-green anterior (prolateral) surface of each femur during courtship display. Unlike other members of the fimbriatus group, legs III are not extended laterally during that display.

Description of male (modified after Otto & Hill 2016; Figures 22-26 ). Males from New South Wales (N=26) ranged from 3.8 to 4.3 mm in length. New males from Queensland (N=2) ranged from 3.3 to 3.5 mm in length. The carapace is dark brown to black in life, fading to a lighter yellow-brown on the sides in preserved specimens. The carapace, including the clypeus, bears an incomplete and variable covering of off-white setae with more prominent off-white stripes extending to the rear behind the lateral eye row on either side. As in other Maratus , one or more stout setae may project forward at the median between the AME. Red-brown setae are scattered along the margins of the eye region. An indistinct middorsal or thoracic tract of off-white setae may extend to the rear behind the eye region, or it may be lacking. The margins of the carapace may be glabrous and dark brown, or a thin marginal line of white setae may be present. The proximal segments of the pedipalps, and the chelicerae are all dark brown to black and glabrous. The eyes do not have the blue or green colouration found in many other Maratus . The ALE are about 4/7 the diameter of the AME, separated from them by less than 1/5 the diameter of an AME. The small PME are nearly equidistant between the ALE and the PLE.

The anterior 2/3 of the dorsal plate of the opisthosoma is covered with a circular area of black scales, interrupted by variable tracts of white scales ( Figures 20-21 ). Behind this the dorsal plate is exposed, black, glabrous, and very shiny. Laterally the dorsal plate is flanked by a thick fringe of long, curved, bicoloured setae on either side. These appear bright white when folded against the opisthosoma where only the distal part of each seta is exposed, but project a brilliant blue, iridescent colour toward the front when the opisthosoma is flattened and these fringes are extended to expose the coloured, proximal part of each seta. From the rear, the proximal portion of each fringing setae is dark brown and not iridescent. The lateral fringes come together at an acute angle (point) toward the rear when retracted. The underside of the opisthosoma is covered with off-white setae but may bear a circular area of brown setae toward the rear, and the brown covers of the book lungs are exposed. The spinnerets are relatively small, brown, and unremarkable.

The coxae and trochanters of all legs are dark with a cover of off-white setae. The sternum is dark brown to black with off-white setae around the margins. Like the chelicerae, the labium and proximal segments of the pedipalps including the endites are dark brown to black and glabrous. Legs I and II are about the same length, much shorter than legs III and IV. Legs III and IV are about the same length. All legs are indistinctly marked and covered with off-white to light-brown setae, with more white on the dorsal femora. Legs I have special markings used in display, however, to include glabrous dark brown or black to dark yellow-green surfaces of the anterior femora, with all segments distal to the femora dark brown on the underside with few setae.

As viewed from below the pedipalps resemble those of other Maratus . The circular embolus has the appearance of a wheel rim, darker or more sclerotized at each rim margin, with a terminal projection bearing a seminal pore at the prolateral side of the rim. The long, bright white to off-white setae of each dorsal tibia and cymbium resembles a 'pom pom', offset by the dark, glabrous proximal segments of each pedipalp. These figure prominently in the male display, when the pedipalps are held in a lower position to display the dark brown, glabrous paturon of each chelicera.

Description of female (modified after Otto & Hill 2016; Figures 27 -28). The two paratype females and five females from the collection of the Australian Museum (N=7) ranged from 3.6 to 4.9 mm in length. One additional female from 14 km west of Rewan, Queensland, illustrated here, was 3.7 mm in length. In all details our female from Queensland closely resembles females collected previously in New South Wales.

The body, legs, and pedipalps of females are covered with a salt and pepper pattern of light to dark grey or brown setae with many light or dark brown spots. Many long white setae project anteromedially from the clypeus, with the appearance of a distinct median tuft above the chelicerae. As in other Maratus , one to several small, stout setae may extend toward the front from the median of the clypeus, just below the AME row. The sides of the carapace bear a covering of long off-white setae. Above each lateral margin of the carapace, closely placed white scales or setae are aligned vertically. The chelicerae are dark brown and glabrous. The ALE are about 1/2 the diameter of the AME. The small PME are almost equidistant from the ALE and the PLE.

The anterodorsal midline of the opisthosoma may bear a black figure in the shape of a double-headed arrow, but otherwise the overall salt and pepper pattern of scales covering the opisthosoma is fairly uniform, with lighter and less patterned setae around the margins. Usually a pair of lighter, but otherwise indistinct, spots, each appearing as a small triangle, can be seen about 2/3 of the distance to the rear from the front of the opisthosoma. The spinnerets are relatively small and brown. The underside of more distal leg segments are more glabrous and brown. The sternum is brown and glabrous but fringed with off-white setae as in the male. Legs I and II are nearly equal in length, much shorter than legs III and IV which are also nearly equal in length.

The paired 'windows' (fenestrae or fossae) of the epigynum are large as is typical in Maratus . The paired posterior spermathecae are prominent but relatively small, somewhat separated from the fenestrae. Prominent ducts with a variable degree of sclerotization can be seen anterior to the large posterior spermathecae.

Immatures ( Figure 29 ). Immature Maratus fimbriatus have not been described previously. The pattern of pigmentation of the first emergent instars (instar II, Figure 29 :1-4), with two dark spots toward the rear, resembles that of older instars ( Figure 29 :5-13).

Courtship display ( Figures 30-34 ). This is an update to our earlier description of the courtship display of male Maratus fimbriatus . As the male moves in a series of discreet steps (5.3-7.4 Hz) in front of a courted female, the expanded and elevated fan, with fringes extended, is first rotated slightly in a direction opposite to the direction of stepping, then quickly rotated back in the direction of stepping. We have observed the same behaviour in males from both New South Wales and Queensland populations, but similar movement does not appear to be a feature of the display of other members of the fimbriatus group. During display, the bright white pedipalps are held in lower position that exposes the dark and glabrous surface of each paturon.

the male was displaying from a horizontal surface. Note the change of direction (11).

the extended fringe is directed toward the front, on either side of the fan.

Habitat and distribution ( Figures 2 , 35-36 ). Like most other Maratus , M. fimbriatus has generally been found on or near the ground. In interior Queensland, this species was found on gravel and on an embankment at the side of a rural road.

Figures

Figure 2. Known distribution of species in the fimbriatus group of the genus Maratus. M. fimbriatus was previously divided into two allopatric species groups, one in the interior of New South Wales (described as M. fimbriatus), and the second in the interior of Queensland (described as M. licunxini). New records of this species that have been posted and documented with reliable photographs in iNaturalist by Stuart Harris, Laurence Sanders and Wayne Winnington-Martin are included here. We have examined a specimen in the Australian Museum from the Pilbara (7) that has been identified as M.?fimbriatus and recorded in the Atlas of Living Australia, and have determined that this represents a new, undescribed species with a much smaller fringe around the opisthosoma. In some cases more than one locality is marked by one circle. The known distribution of M. ammophilus is parapatric to the closely-related M. speculifer, with both species found on sands near the Indian Ocean coast of Western Australia. Other members of the group are known only from isolated sites in the interior of South Australia.

Figure 20. Comparison of male types for Maratus licunxini with other variants of M. fimbriatus. 1-2, Two versions of the same image depicting the holotype for M. licunxini, Carnarvon QLD. The description of that species (Baehr & Whyte 2016) referred to the presence of an inverted Y-shaped patch of dense white setae at the anterior edge of the opisthosoma, visible in (1). However (2) reveals the presence of an additional, curved tract of white setae on either side of this Y-shaped tract, not mentioned in that description. 3-4, Paratype 1 for M. licunxini is clearly rubbed and the pattern of setae is not clear. 5-7, Setation of paratype 2 for M. licunxini is intact and reveals a more complex pattern. 8, M. fimbriatus, Coolatai NSW. 9, M. fimbriatus, northwest of Wyuna QLD. 10, M. fimbriatus, west of Rewan QLD. Photo credits: 1-7, Owen Seeman, Queensland Museum, used with permission; 8, Stuart Harris and 9, Laurence Sanders each used under a CC BY-NC 3.0 AU license.

Figure 21. Schematic drawings depicting variation in the placement of white scale tracts on the dorsal opisthosoma of male Maratus fimbriatus. 1, Typical form that has been found in New South Wales. 2, Holotype male for M. licunxini, Carnarvon QLD (Figure 20:1-2). 3, Paratype 2 for M. licunxini (Figure 20:5-7). 4, Holotype male for M. licunxini according to published description (Baehr & Whyte 2016). 5, M. fimbriatus, northwest of Wyuna QLD (Figure 20:9), with medial white tracts similar in shape to those found in specimens from New South Wales but otherwise similar to the holotype for M. licunxini (2). 6, M. fimbriatus, west of Rewan QLD, with all four white tracts converging toward the rear, and five pairs of black spots near the median (Figure 20:10).

Figure 22. Male Maratus fimbriatus from the type locality near Nyngan, New South Wales.

Figure 23. Two male Maratus fimbriatus from 14 km west of Rewan, Queensland. Note the complex pattern of white scales on the anterior 2/3 of the dorsal opisthosoma. 11-12, Depending on the relative angle of illumination, the reflectance of the glabrous posterior 1/3 of the dorsal opisthosoma varies.

Figure 24. Two male Maratus fimbriatus from 14 km west of Rewan, Queensland, in alcohol.

Figure 25. Medial to lateral views of the left pedipalp of two male Maratus fimbriatus from 14 km west of Rewan, Queensland, in alcohol.

Figure 26. Ventral views of two male Maratus fimbriatus from 14 km west of Rewan, Queensland.

Figure 27. Female Maratus fimbriatus from 14 km west of Rewan, Queensland.

Figure 29. Two immature male Maratus fimbriatus from 14 km west of Rewan, Queensland. 1-4, Second instar of the first male. Note the distinct pair of dark spots toward the rear of the opisthosoma.

Figure 30 (continued on next page). Sequential frames from a 25 fps video of courtship display by a male Maratus fimbriatus from 14 km west of Rewan, Queensland (5.3 Hz steps). Rotation of the fan in a direction opposite to the stepping direction in followed by rotation of the fan in the direction of each step.

Figure 32. Sequential frames from a 25 fps video of courtship display by a male Maratus fimbriatus from the type locality near Nyngan, New South Wales (6.3 Hz steps), showing rotation of the fan in two stages with each step. Note the change of direction (19).

Figure 33. Sequential frames from a 25 fps video of courtship display by a male Maratus fimbriatus from the type locality near Nyngan, New South Wales (7.4 Hz steps), showing rotation of the fan in two stages with each step. Here

Figure 34. Courtship display by two male Maratus fimbriatus from 14 km west of Rewan, Queensland. 12, Note how

Figure 35. Male Maratus fimbriatus on or near the ground west of Rewan, Queensland (24.97704°S, 148.3904°E). Photo credits: 1-6, © Wayne Winnington-Martin, used with permission.

Figure 36. Habitat of Maratus fimbriatus 14 km west of Rewan, Queensland (24.976330°S, 148.390200°E). These spiders were collected in gravel and on the embankment below a tree. 1-4, © Donna and Lawrence Sanders, used with permission.