Maratus cinereus, Otto & Hill, 2017

Otto, Jürgen C. & Hill, David E., 2017, Five new peacock spiders from eastern Australia (Araneae: Salticidae: Euophryini: Maratus Karsch 1878 and Saratus, new genus), Peckhamia 147 (1), pp. 1-86 : 17-34

Maratus cinereus , new species

Type specimens. The holotype male (♂ #1), nine paratype males (♂ #2-10), one paratype male collected when penultimate and reared to maturity (♂ #11) and seven paratype females (♀ #1-7) were collected near Stanthorpe , Queensland (S28.75961°, E151.86272°, 16 SEP 2015, coll. M. Doe, M. Duncan, A. Fletcher). Three paratype females (♀ #8-10) were reared from eggs deposited by the paratype females collected near Stanthorpe . All types will be deposited in the Queensland Museum, Brisbane.

Etymology. The species group name ( cinereus, Latin , m., adjective, English translation ashen or like ashes) refers to the speckled, greyish colouration of the opisthosoma of the adult male.

Diagnosis. Male and female genitalia and other similarities mentioned earlier clearly place this species in the anomalus group of the genus Maratus . M. cinereus is very closely related to M. lentus . Both have similiar morphology, including distinctive "cuffs" of off-white setae around the proximal tarsi of legs I and II in the males. The colouration of the fan (dorsal opisthosomal plate of the male) of M. cinereus is generally grey to blue, green, or purple, corresponding to the grey colour of the eye region. Male M. lentus are mostly orange in colour, with a wide band comprised of grey scales or setae on the lateral margins of the fan. Courtship display by males of the two species is similar. Both species tend to kick with one raised and flexed leg III, but M. cinereus does this much more frequently. M. cinereus moves the fan sideways but does not tend to wave it or to extend the spinnerets during display as do the male M. lentus . Both species often move one pedipalp (ipsilateral to the flexed leg III) laterally during display, exposing the paturon of the ipsilateral chelicera to the female. Females of M. cinereus and M. lentus are virtually indistinguishable.

Description of male ( Figures 19-24 ). Males are 4.2-4.5 mm in length (n=10). The chelicerae are black and glabrous. Grey setae extend diagonally from the black clypeus toward the midline between the chelicerae. The eye region and the sides of the carapace just below the lateral eyes are covered with uniform brown to grey scales. The PME are slightly closer to the PLE than to the ALE.

The entire carapace is black and glabrous with two short but wide tracts of white scales on either side and a pair of wide, converging bands of white scales extending to the rear behind the posterior eye row. There is no marginal band and the lateral rims of the carapace are black but clearly visible.

The dorsal opisthosomal plate (fan) is covered with setae of variable colour that tend to be more iridescent or brighter in colour laterally. The colour of these setae varies from light brown (particularly near the midline) to light green, purple or blue. On this background are many black spots or speckles, and one pair of small but distinct black spots toward the rear ( Figures 19-20 ). The lateral margins of the fan are moderately fringed with either black or off-white setae. The underside of the opisthosoma is brown but covered with off-white to light brown setae, with a narrow black line separating the venter from the many off-white to grey setae of each margin ( Figure 21 ). The underside of the legs, sternum, labium, endites, and pedipalps is dark brown to black with few setae, except for the many longer, off-white setae beneath the coxae and femora of legs III and IV. The legs are relatively uniform in colouration, covered above with off-white scales. There is a distinct, thin black stripe running along the front of the femur, patella and tibia of each leg III. The scale cover of the front of each femur III tends to match that of the dorsal opisthosoma, but the scale cover of the distal segments of each leg III is more uniform off-white.

Dorsally (or oriented toward the front in live spiders) the pedipalps are covered with long setae, off-white on basal segments and much longer and darker or grey on the cymbium. The detailed structure of each pedipalp is similar to that of other members of the anomalus group, with a blunt or bifurcated apex of the outer ring of the embolus above the shorter and sharply pointed apex of the inner ring ( Figure 24 ).

in alcohol.

Description of female (Figures 25-30). Females are 4.4-5.3 mm in length (n=10). Cuticle of the eye region and upper carapace, and a wide median band extending behind the eye region, is dark brown. Otherwise the prosoma, chelicerae, pedipalps, and legs are light brown and translucent, or white in specimens fixed in alcohol. The chelicerae are glabrous, and the clypeus is mostly glabrous except for some longer white setae that originate just below the front eye row and extend forward toward the midline. The eye region and the upper part of the carapace beneath the eyes bears a cover of uniform off-white to brown scales or setae. The sides of the carapace are glabrous and there is no marginal band. The thick lateral rims of the carapace are exposed and glabrous. A wide band of off-white scales may be present (unless worn) on either side of the upper carapace, just behind the posterior eye row and separated by the wide median band of dark cuticle. The posterior carapace behind these bands is almost completely glabrous. The PME are about the same distance from the ALE as from the PLE.

Figure 26. Six different (1-3, 4-6, 7, 8-9, 10-11, 12) living female M. cinereus .

The dorsal opisthosoma is covered with a variegated pattern comprised of dark brown markings on a background of light brown scales or setae (Figures 25-26). When well-defined (Figure 26: 3, 12) one can observe a dark stripe on either side of the midline, flanked by about 10-12 more-or-less parallel and black lines running in an anterolateral direction from this stripe. On the sides and below, the opisthosoma is light brown with a uniform cover of white to off-white setae ( Figure 27 ). An indistinct pair of dark or black lines may be present on either side of the venter. Scattered white setae are present under the posterior sternum and under the coxae and femora of legs III and IV. Otherwise the underside of the sternum, labium, endites, pedipalps, and legs is light brown, translucent, and mostly glabrous. The legs are uniform in colouration with off-white setae above. Legs I and II are shorter, of about the same length, and mostly glabrous. Legs III and IV are longer with more scale cover, and leg III is the longest.

The epigynum is typical for females of the anomalus group, with darker or more sclerotized ducts visible externally at the rear of each fossa, on either side (Figure 30).

Immatures. Emergent (second instar) juveniles have dark pigment and a cover of off-white setae in the eye region ( Figure 31 : 1-3). Penultimate females ( Figure 31 : 4-8) and penultimate males ( Figure 31 : 9- 13) are similar to adult females in appearance.

Courtship display ( Figures 32-35 ). When they display to females, male Maratus cinereus crouch and raise their opisthosoma to display the fan without distinct waving but with frequent, shorter and faster sideways movements. Spinnerets are seldom extended during this display. The most active part of this display is the frequent, rapid extension of one leg III, and sometimes boths legs III. When close to a female, a male will often move one pedipalp to the side to exposed the underlying paturon of the ipsilateral chelicera, and this pedipalp may be moved slowly up and down in that position.

Habitat. Maratus cinereus was found on grasses in an open woodland near Stanthorpe, Queensland ( Figure 36 ).

by Michael Doe.

Figures

Figure 19. Living holotype (1-3) and six paratype (4-5, 6, 7-9, 10, 11, 12) male Maratus cinereus.

Figure 20. Four paratype (1-3, 4, 5, 6-9) male Maratus cinereus. The dorsal opisthosoma and anterior femora III tend to have setae of the same colour. Compare the dull green of one male (2-3) to the light blue of another (7-9).

Figure 21. Ventral views of the living holotype (1) and three paratype (2-4) male M. cinereus.

Figure 22. Holotype (1-3) and two paratype (4-6, 7-9) specimens of the male M. cinereus

Figure 23. Holotype (9) and seven paratype (1-3 & 11, 4, 5, 6, 7, 8, 10) specimens of the male M. cinereus in alcohol.

Figure 24. Medial to lateral views of the left pedipalp of the holotype (1-5) and two paratype (6-8, 9-12) male M. cinereus.

Figure 27. Ventral view of four living female M. cinereus.

Figure 31. Immature Maratus cinereus. 1-3, Emergent or second instars. 4-8, Penultimate females. 9-13, Penultimate males. In addition to their bulbous pedipalps, these males also have the vertical tracts of white setae on the sides of the carapace that are characteristic of the adult male.

Figure 32. Display positions of five different Maratus cinereus. 7-9, These sequential photographs show movement of the right pedipalp to the side to expose the chelicera behind it.

Figure 33. Display positions of five different Maratus cinereus. 1-3, Three sequential positions showing extension of leg LIII. 5-6, Two sequential positions showing extension of the spinnerets (6). The right pedipalp was held to the side to expose the right chelicera. 7-9, Here the fan was completely expanded as the opisthosoma was flattened. Compare this to the width of the partly retracted fan (5-6). Note the light-coloured setae of tarsi I and II, and their distinctive proximal "cuffs."

Figure 34. Sequential frames (0.04s/frame or 25fps) showing the courtship display of a male Maratus cinereus. Frequent, rapid kicks with the elevated leg R3 are indicated with arrows. Between kicks, this leg was held in an elevated but flexed position. There was little to no movement of the fan and spinnerets during this display.

Figure 35. Consecutive but not sequential frames selected from a 25fps video of the courtship display of a male Maratus cinereus, to illustrate successive positions. Leg movement is highlighted with arrows. There was some movement of the fan during this sequence but it was not waved. Even when both legs III were moved rapidly (10-21), their movement was not synchronized or bilaterally symmetrical.

Figure 36. Grassy habitat of M. cinereus near Stanthorpe, Queensland. Photograph