Maratus sarahae Waldock 2013

Jürgen C. Otto & David E. Hill, 2014, Spiders of the mungaich group from Western Australia (Araneae: Salticidae: Euophryinae: Maratus), with one new species from Cape Arid, Peckhamia 112 (1), pp. 1-35 : 18-28

Maratus sarahae Waldock 2013

Maratus sarahae was first collected by David Knowles at Bluff Knoll in the Stirling Range National Park in 1988 ( Waldock 2013). The M. sarahae figured in this paper were found more recently by Jürgen Otto at Bluff Knoll (SEP-OCT 2011, S 34° 22' 35.5'', E 118° 15' 14.8'', elevation ~1036 m; Figures 12 :2, 15: locality 4). Preserved specimens drawn from this group are presently in the collection of Jürgen Otto.

Male features ( Figures 24-30 , Table 2 ). See Waldock (2013) for a description of the holotype male (WAM T125614). Here we illustrate characters of a male Maratus sarahae (♂#5) from Bluff Knoll, and compare these to corresponding characters of a male M. mungaich ( Table 2 ). The eye region of M. sarahae is dark, with three indistinct longitudinal tracts of dark red-brown scales. Except for scattered white scales, particularly around the front eyes, the carapace is dark, but like M. mungaich has a bright white marginal band. The fan ( Figure 25 , Table 2 ) has a similar pattern with respect to the presence of a dark central figure and a dark spot on each flap, but differs significantly with respect to details of its pattern of scales. The femur III of M. sarahae bears dorsal and ventral fringes of long white setae, much more pronounced than that seen in M. mungaich . The tibia III has both white and black setae, with a fringe of long setae beneath. The metatarsus and proximal tarsus III of M. sarahae is covered with many white scales, including a prominent fringe of white setae beneath. The distal tarsus III also bears a prominent cover of long black setae, not seen in M. mungaich . As in M. mungaich , tenent setae of the foot pads are grey.

As shown in Figure 30 , the male pedipalp resembles that of other Maratus , and is considered to be of limited use for identification. The appearance of the terminal portion of the coiled embolus in published drawings of Maratus and related euophryines varies greatly depending on the style of the artist, and the exact angle of the view that is drawn. The terminal part of this coil in M. sarahae has a longer, outer projection, and a shorter, inner projection. This is similar to that described for the related M. mungaich ( Figure 4 in Waldock 1995), but it is also very similar to the embolus of the more distantly related M. anomalus ( Karsch 1878) from eastern Australia ( Prószyński 1984, Żabka 1987, Otto & Hill 2012c, 2012e).

Female features ( Figures 31-33 ). The females of M. sarahae , like those of other Maratu s, are relatively nondescript with cryptic colouration and subtle features.

Relative to the spermatheca, the windows (or fossae) of M. sarahae are relatively smaller than are those of M. mungaich . This is expressed in the ratio [b/c] ( Figure 33 :1) which is about 0.5 in M. sarahae , and 0.8- 0.9 in M. mungaich . The width of both windows relative to the epigynum [d/e] is about 0.6-0.7 in M. sarahae , and 0.8-0.9 in M. mungaich . The relative width of the septum [a/b] varies greatly, from about 0.4-0.7 in our examples of M. sarahae , to about 0.3-0.4 in M. mungaich . These differences in proportion may relate to differences in overall body size of the two species, or of the respective specimens.

5

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4

3

2

1

0

Male courtship display ( Figures 34-35 ). In general, Maratus sarahae appeared to move its legs III, and flex these legs at the tibio-metatarsal joint, frequently during display, whereas M. mungaich appeared to rely more on side-stepping with legs III extended and held in a relatively static position. Male M. sarahae may also side-step in front of a female, but appeared to do this much less than did male M. mungaich . Videos depicting the display of M. sarahae ( Otto 2012) and M. mungaich ( Otto 2013) have been posted recently and provide a good introduction to the temporal sequence of these movements. Only the 'fan dance' of the male is depicted here. Like M. mungaich , males have many other signals in their courtship repertoire, including single leg waving at a distance, and semaphore movements of legs III with the fan lowered as the female is approached.

Habitat. Maratus sarahae has only been found on or near the ground in the eastern part of Stirling Range National Park in southwestern Western Australia ( Figures 12 :2, 15, 36).

Size of Maratus sarahae . Relative size is only useful within limits. In addition to intraspecific genetic variation, this may vary from year to year, or from place to place, solely as the result of environmental conditions including relative abundance of prey. Overall measurements of body length may not be reliable, due to changes in the relative position of prosoma and opisthosoma, as well as shrinkage, of preserved specimens. For spiders like Maratus , with a large and flexible pedicel related to the great extent to which these spiders can rotate the opisthosoma, 'body length' is thus an even less precise measurement. Nonetheless, the Maratus sarahae adults that have been measured are among the largest known Maratus ( Otto & Hill 2011b, Waldock 2013), considerably larger than the related M. mungaich ( Table 3 , Figure 37 ). Waldock's M. sarahae types were much larger than any that we have observed (male length of 7.4 mm compared with our average of only 5.6 mm), but her drawing of the male ( Waldock 2013, Fig. 3 ) depicts a length of only ~4.5mm.

Figures

Figure 3. Paratype male (♂#2) M. avibus. The scale cover of the dorsal opisthosoma of this individual was more grey, contrasting with the bright band of iridescent blue-purple scales at the rear. 1-2, This spider displayed at a distance by extending and flexing a leg III at the femuro-patellar joint.

Figure 4. Views of the fan or dorsal opisthosomal plate of M. avibus. 1, Extended fan of the holotype (♂#1). Note the hyperextension of femuro-patellar and patello-tibial joints of leg LIII, at right. 2, Right posterior margin of folded fan of the holotype (♂#1), showing the tightly packed arrays of iridescent and orange or red-orange pigmented scales that give the fan its colour. 3, Extended fan of paratype (♂#2). 4, Top of folded fan of a paratype specimen in alcohol (♂#3). The orange scales of the posterior band of this spider are not visible and may have worn off. 5, Ventral view of living paratype (♂#2). Note how the folded flaps of the fan meet at the venter. 6, Detail of scales covering the left side of the folded fan of a paratype (♂#3).

Figure 12. Localities where spiders of the mungaich group have been reported, all in Western Australia. 1, Radar topography map of Australia, based on data collected by the NASA Shuttle Radar Topography Mission. 2, Area of interest in the southern part of Western Australia, corresponding to the inset rectangle in (1). Numbers (encircled) correspond to spiders that we have examined, and are described under each of our species accounts. Outlined distributions are based on localities described by Waldock (2013). To date, all species described in this group have an allopatric distribution. Collection from more sites within this area should contribute to our understanding of relationships between the isolated populations represented by these species.

Figure 17. Detailed appearance of the very wide fan of male M mungaich. 1, Expanded fan of a male M. mungaich from Mt. Dale. 2, Retracted or folded fan of a male M. mungaich from the Talbot Road Nature Reserve (photograph © Jean and Fred Hort, used with permission). Specimens recently observed by both Bokhari (2012) and Hort & Hort (2012) from this area showed this pattern with two small blue spots at the center of the black central shield, with a more extensive group of redorange scales bordering that shield toward the rear. Numbered features (1-12) are described and compared with corresponding features of M. sarahae in the next section.

Figure 24. Front views of a male M. sarahae (♂#5), displaying with elevated fan and extended legs III. 1, The dark carapace contrasts with the cover of long white setae covering the pedipalps and legs (except for the darker patella-tibia III). 2, Detail of extended leg LIII, showing fringes of long setae above the femur, and beneath the femur, patella, tibia, and metatarsus. Long black setae are mixed with white setae under the patella and tibia. The distal tarsus also has a thick brush of black setae, not to be confused with the grey tenent setae of the claw tufts that are not visible in this view.

Figure 25. Dorsal opisthosoma of a male M. sarahae (♂#5), with fan extended (1) and retracted or folded around the lateral margins (2). Numbers 1-12 identify features that are compared with corresponding features of M. mungaich in Table 2. As in M. mungaich, the fan of M. sarahae is very wide.

Figure 26. Expanded fan of six different male M. sarahae, showing variation in the general pattern. Pigmented red to redorange scales comprise distinct figures on a background of iridescent scales. Although there are individual differences in the colouration of the iridescent scales, this colour also varies greatly as a function of illumination and humidity.

Figure 27. Fan of a male (♂#5) Maratus sarahae. 1, Black or bright red-orange scales form figures on a background of blue-green iridescent scales. 2, Mating pair. The flaps of the male opisthosomal fan are folded unless the spider is displaying to a female.

Figure 28. Changes in appearance of the opisthosomal fan of a male (♂#5) Maratus sarahae. 1-2, As the male displayed to a female, the orientation of the fan relative to incident and reflected light changed its brightness considerably. 3-4, Another example of a change in brightness related to the orientation of the fan. 5-6, Spider showing colour change related to humidity, ~40 s after removal from a vial containing moist cotton (~100% humidity, 5), and three minutes later after drying (6).

Figure 29. Dorsal and ventral views of a male (♂#5) Maratus sarahae. 1, Dorsal view of living spider. 2, Dorsal view of specimen, in preservative. 3, Ventral view of living spider. 4, Ventral view of specimen in preservative. Note the change of colouration of the normally blue-green iridescent fan scales when submerged in an aqueous solution. The many long white setae that cover the legs of this spider are also much less apparent when preserved. The carapace, with a marginal white band, is mostly dark and glabrous, with some dark brown to red brown scales. The generally grey colour of the cuticle of the living spider also differs from the yellowish colouration of the preserved specimen.

Figure 30. Left pedipalp of a male (♂#5) Maratus sarahae. 1-2, Lateral views. 3, Drawing of lateral view. 4, Drawing of ventral view. 5, Medial view. 6-8, Ventral views.

Figure 31. Six different female Maratus sarahae. 1-2, Detailed view of one female (♀#5), showing mixture of white and darker red-brown scales on both carapace and dorsal opisthosoma. This contrasts (1, arrow) with a lateral opisthosomal band of white scales, a feature that is more prominent in the other females spiders shown here (3-8). Some of these females have a more or less indistinct median figure on the dorsal opisthosoma (4, arrow), and most have a dark band (7, arrow) separating the dorsal area of the opisthosoma from a lateral marginal band comprised of lighter-coloured scales.

Figure 32. Ventral views of a female M. sarahae (♀#5). 1, Underside of living spider. 2, Underside of preserved specimen. 3, Ventral view of anterior opisthosoma, showing epigynum. 4, Detail of epigynum, at high contrast.

Figure 33. External view of epigynum of two other M. sarahae females. The septum of each was somewhat wider than that of the female shown in Figure 31. 1, Measurements corresponding to letters (a-e) were used in the evaluation of proportions of respective structures.

Figure 34. Front view of four different Maratus sarahae males as they displayed ('fan dance') to females. Each spider had three irregular longitudinal bands of dark red scales on the optic quadrangle; the carapace was otherwise quite dark. Note the black setae covering the distal tarsus III of each spider, and the prominent fringe of long setae on the underside of tibia III (white and black setae) and metatarsus III (white setae only). Flexion of legs III at the tibio-metatarsal joint (1, arrow) was observed frequently in this species. As with M. mungaich, a series of intermittent and sudden lateral rotations of the extended and elevated fan, to either side, was an important part of this display.

Figure 35. Sequential (1-9), but not consecutive, frames from a video recording of a male (♂#110) Maratus sarahae as it displayed to a female ('fan dance'). In each frame, arrows indicate prior movement that led to each observed position. 1, Pedipalps lowered. 2-3, Pedipalps raised and fan rotated to the (spider's) right. 4, Pedipalps lowered and fan rotated to the left. 5, Left pedipalp lowered, fan rotated to the left, and left leg III rotated to the left. 6, Right pedipalp lowered, fan rotated to the right, and left leg III flexed. 7, Left leg III extended. 8, Pedipalps lowered, fan rotated to the left, and left leg III rotated to the left. 9, Pedipalps lowered, fan rotated to the left, and left leg III rotated to the right. This species typically combined rapid pedipalp, fan, and leg movements while displaying in place as shown here.

Figure 37. Comparison of an adult male Maratus sarahae from Bluff Knoll with an adult male M. mungaich from Mt. Dale. The larger M. sarahae is much heavier bodied, with prominent fringes of long white setae under legs III.

Tables

Table 2. Comparison of the dorsal opisthosoma of male Maratus sarahae with that of male M. mungaich, based on features identified and enumerated in Figures 17 and 25.

feature	description	♂ M. sarahae	♂ M. mungaich
1	anterior marginal band	lateral orange to red tracts separated medially by white or black scales
2	transverse band	two broad orange to red tracts extending more than	narrower orange to red tracts extending about 1/2 of
		3/4 of distance from median to lateral margin on	distance from median to lateral margin on each side,
		each side, separated medially by a large chevron-	either joined or separated at median by the background
		shaped black area pointed forward	field of iridescent scales
3	transverse band	orange to red tracts extending laterally on each side	shorter diagonal orange to red tracts each attached to
		from anterior part of central dark figure (9), broken	ipsilateral tract of transverse band 2 antero-medially,
		up into smaller patches laterally	and separated from the central dark figure (9) by
			iridescent background scales
4	transverse band	orange to red tracts extending laterally on each side	orange to red tracts extending laterally on each side
		from posterior part of central dark figure (9), more	from central part of central dark figure (9) toward the
		solid than band (3), may be interrupted	lateral dark spot, may be interrupted
5	transverse band	uniform narrow band with red to orange scales	broken into variable series of small tracts curving to the
		laterally, joined across median by tract of black	rear on either side, or indistinct
		scales with width equal to that of the central dark
		figure (9)
6	transverse band	uniform narrow band (wider than 5) with red to	absent or indistinct, may be represented by a line of
		orange scales laterally, joined across the median by a	small red to orange spots
		wider group of black scales
7	lateral red tract	with (8) in a posterior position, comprise a larger,	with (8) in a posterior position, comprise a smaller band
		oval patch or red to orange scales on each side,	or red to orange scales on either side, appearing as an
		appearing as an extension of both bands (3) and (4)	extension of band (4) only
8	lateral dark spot	relatively large, bounded by tract (7) anteriorly for a	relatively small, bounded by only a narrow span of tract
		distance equal to its diameter	(7) scales anteriorly
9	cental dark figure	wide field of dark scales separated into anterior and	much narrower, shield-shaped area of black scales with
		posterior areas by a thin medial, transverse tract of	one or two small, ovoid blue spots aligned on the
		blue scales, the anterior area joining the lateral	midline, joining the lateral tracts of band (4) only, at the
		tracts of band (3), and the posterior area joining the	center
		lateral tracts of band (4)
10	antero-lateral iridescent tract	behind anterior margin (1), anterior band of	distinctive wide area (patch) of background iridescent
	(10)	iridescent (background) scales fairly uniform with	scales at antero-lateral margin of fan, usually appears
		no wide antero-lateral area	green to drab or olive-green from the front, extending
			from anterior margin (1) to the curved anterior limit of
			tract (7), approaching close to the lateral dark spot (8)
11	setation of spinnerets	grey to black setae
12	setation of anal tubercle	group or patch of uniform bright white setae, converging distally