Maratus lobatus, Jürgen C. Otto & David E. Hill, 2016

Jürgen C. Otto & David E. Hill, 2016, Seven new peacock spiders from Western Australia and South Australia (Araneae: Salticidae: Euophryini: Maratus), Peckhamia 141 (1), pp. 1-101 : 41-49

Maratus lobatus , new species

Type specimens. Five paratype females (♀ #1-3, 5-6) were collected at Helms Arboretum, 15 km NNW of Esperance (33.72556 °S, 121.84250 °E, 15-17 NOV 2014, coll. A. Fletcher and M. Doe). The holotype male (♂ #1), two paratype males (♂ #2-3), and one paratype female (♀ #4) were raised from eggs produced by one of these females. These will be deposited in the Western Australian Museum, Perth.

Etymology. The species group name ( lobatus, Latin , m., adjective, English translation lobed or having lobes) refers to the lobate shape of the lateral flaps of the dorsal opisthosomal plate of the male.

Diagnosis. This species closely resembles the eastern Maratus harrisi Otto & Hill 2011 , and we place both in a harrisi group within the genus Maratus . The fan of the male M. harrisi has a single pair of white spots associated with the central figure, whereas M. lobatus has one pair of straight lines and one pair of curved white lines, also comprised of white scales, in this position ( Figure 47 ). The male M. harrisi that we have

examined have two contiguous apices of the embolus of each pedipalp, and these are separate in M. lobatus . The female M. lobatus resembles many other species of Maratus , and cannot be compared here with the female M. harrisi which has not been described. The epigynum of female M. lobatus that we have examined varies greatly between individuals.

Description of male ( Figures 48-52 ).

Males (N=2) ranged from 4.92 to 5.07 mm in length.

The clypeus is black, almost devoid of setae. The carapace is almost entirely black, with dark red and grey setae around the eyes or the anterior and lateral margins of the eye region. The sides of the carapace are black and glabrous, but there is a prominent marginal band comprised of bright white setae. Behind the posterior eye row a narrow median and two wider lateral tracts of off-white setae extend less than half-

way to the posterior margin of the carapace, merging anteriorly. These may be more distinct in recently molted individuals ( Figure 48 :10). The PME are clearly closer to the PLE than to the ALE.

The fan bears a distinctive pattern of black to red-brown and white scales on a light blue (toward the rear) or grey (toward the front) background comprised of densely packed scales. On this background lies a large 'V' figure pointed toward the front, flanked by a smaller pair of 'U' figures, open toward the front. These figures are dark red-brown and surrounded by white setae toward the front. There is a transverse

line of bright white scales extending laterally from each side of the large 'V' figure, and two curved lines of bright white scales surround the posterior ends of this figure ( Figures 47 :4-5, 49). The anterior margin of the opisthosoma is black or dark grey, with many long black setae projecting anteriorly. The rear margin of the fan is defined by a broad black band interrupted by a tract of white setae on either side. Black areas of the fan may be outlined with dark red-orange scales. The lateral margins of the dorsal plate are lobate

flaps that are normally wrapped around the opisthosoma, but extended during courtship display. The dorsal surface of these flaps is dark anteriorly and dull blue-green posteriorly, fringed with bright white setae. To the rear of and beneath the dorsal plate the opisthosoma is black with a cover of black setae ( Figure 49 :2, 5). A small white triangle of colular setae is present above the black spinnerets. From

below, the opisthosoma, coxae, sternum, labium, and endites are mostly grey and glabrous, except for a cover of short setae toward the front of the opisthosoma, and a group of setae originating with the posterior sternum.

Legs I and II are shorter and of similar length. Legs III and IV are longer, and legs III are by far the longest. Legs I, II, and IV are dark with irregular rings comprised of white or off-white setae. Legs III are dark brown with scattered setae, but the metatarsi are completely black and the tarsi are bright white. From the front ( Figure 50 :1) the pedipalps are covered with long white setae. The embolus of the pedipalp is

typical for Maratus , with two distinct and sharply pointed apices, the outer one larger ( Figure 52 ).

Description of female ( Figures 53-56 ). Females (N=3) ranged from 6.16 to 6.46 mm in length. The chelicerae and lower part of the clypeus are dark, almost black, and glabrous, but long white setae project forward from the upper clypeus beneath the anterior eye row. The carapace is also dark, with regular brown setae in the eye region and fewer setae to the sides and rear. The margin of the carapace is black

and glabrous and a regular marginal band is not present. The PME are midway between the ALE and PLE. The dorsal opisthosoma is covered with dark brown setae and an indistinct pattern of several paired spots, but is flanked at the posterolateral margins by a wide and distinctive marginal band of light brown ot off-white setae. There is a small white, triangular colular patch of setae, and the spinnerets are grey or light brown. The underside of the opisthosoma is almost uniform light brown. The coxae, sternum, labium, and endites are light grey with scattered setae.

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Legs I and II are shorter and similar in length and legs III and IV are longer. The legs and pedipalps are dark brown. The legs and pedipalps bear scattered patches of light brown setae and are dark at the joints. The pedipalps are fringed along their length with longer, light brown setae, with distal grey setae ( Figure 56 :2). The epigynum ( Figure 55 :9-13) is variable with respect to the width of the septum

separating the fenestrae, and the extent of sclerotization of the ducts visible as dark objects beneath the posterior fenestrae.

Immatures. Penultimate male and female Maratus lobatus are shown in Figure 57 . These are similar in general appearance and closely resemble the adult female, except for the narrow marginal band and the inflated and light-coloured developing pedipalps of the male. At this stage the two-tone pattern of the dorsal opisthosoma of both sexes includes elements that appear in colour on the fan of the adult male.

Courtship display ( Figures 58-59 ). Courtship was observed indoors in a naturalistic setting. Although rapid waving of legs III is an important part of the courtship display of Maratus harrisi (unpublished observation), this appears to play no part in the display of M. lobatus . M. lobatus simply raise and extend the fan, and then intermittently (at irregular intervals from about 0.15 to 2.5 s) vibrate the fan by moving

it from side to side. This vibration is so rapid that it occurs within a single frame of a 25fps video ( Figure 59 ). The pedipalps are also vibrated at a similar, irregular frequency, but this is not always synchronous with fan vibration.

Distribution.

( Figure 1 ).

Localities where Maratus lobatus has been found are shown in Table 2 and in the map

Figures

Figure 1. Localities for seven new Maratus species from the southern coast of Western Australia and South Australia. Maratus albus and M. lobatus are widely distributed. M. australis and M. vultus are each known from two localities near the southern coast of Western Australia. Each of the other three species (M. bubo, M. tessellatus, and M. vespa) has been found at a single locality in the southwestern corner of Australia, south of Perth.

Figure 47. Comparison of a male Maratus lobatus from Port Lincoln, South Australia (4 - 5) with three male M. harrisi from New South Wales (1), Tasmania (2), and Victoria (3). Photographs (4) © Michael Doe, (5) © Adam Fletcher, both used by permission.

Figure 48. Holotype (1 - 3) and two paratype (4 - 12) male Maratus lobatus reared from eggs deposited by a female collected at the type locality (Helms Arboretum NNW of Esperance).

Figure 49. Details of dorsal opisthosoma of the three male Maratus lobatus types. 3, 6, Fan expanded and raised during courtship to reveal the flaps (lobes, or extensions of the dorsal opisthosomal plate) that are otherwise folded under the opisthosoma.

Figure 50. Male Maratus lobatus. 1, Detail of face, showing black clypeus, chelicerae, and sides of carapace. 2 - 3, Two ventral views, showing flaps folded under the opisthosoma.

Figure 51. Two male Maratus lobatus in alcohol.

Figure 52. Medial to lateral views of the left pedipalp of two male Maratus lobatus in alcohol. Insets (5, 10) and one lateral view (1) show the clear separation of the larger outer and the smaller inner apices of the embolus, both sharply pointed.

Figure 53. Four different female Maratus lobatus. Note the wide bands of light-coloured (light brown to off-white) setae on the posterior margins of the opisthosoma, in some cases offset from the dark brown dorsum by a black line (9).

Figure 55. Female Maratus lobatus in alcohol. 9 - 13, Detail of epigynum of five different females. Note variability in width of septum and sclerotization of ducts visible behind the posterior portion of each fenestra.

Figure 56. Female Maratus lobatus. 2, Detail of face. 3, Ventral view.

Figure 57. Views of two penultimate male (1 - 6) and three penultimate female (7 - 12) Maratus lobatus. The pattern of four light-brown areas across the dorsal opisthosoma of both males and females corresponds to the position of the four patches of white scales on the fan of the adult male (Figure 49).

Figure 58. Display positions of two different male Maratus lobatus facing a female.

Figure 59. Sequential frames from a 25 fps video showing the display of a male Maratus lobatus in front of a female. Omitted frames represent intervals when the male did not move. Vibration of the fan and pedipalps is indicated with arrows.