Maratus albus, 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 : 2-16

Maratus albus , new species

Type specimens. The holotype male (♂ #1), six paratype males (♂ #3-6, 8-9), and four paratype females (♀ #2, 4, 6-7) were collected at Eyre Bird Observatory, Nuytsland Nature Reserve, WA (32.24788 °S, 126.30167 °E, 2 OCT 2013, coll. J. Otto, coastal sand dune vegetation). Three paratype males (♂ #K5, K6, and one unnumbered) and two paratype females (♀ #K1, K3) were collected at Flinders Chase National

Park, Kangaroo Island, SA [either Cape Du Couedic at 36.0599 °S, 136.70585 °E, 24 OCT 2015, coll. J. Otto, coastal heath, or Weirs Cove at 36.0546 °S, 136.71752 °E, 28 OCT 2015, coll. J. Otto, coastal heath]. One paratype male (♂ #K8) was collected at D'Estrees Bay, Kangaroo Island, SA (35.939679 °S, 137.59777 °E, 25 OCT 2015, coll. J. Otto, 'pig face' [ Carpobrotus sp.] and other beach vegetation). One paratype male was collected at Port Lincoln, SA (34.7325 °S, 135.88333 °E, 12-13 NOV 2014, coll. A. Fletcher and M. Doe). The WA specimens will be deposited in the Western Australian Museum, Perth, and the SA specimens will be deposited in the South Australian Museum, Adelaide.

Etymology. The species group name ( albus, Latin , m., adjective, English translation white) refers to the many prominent white setae of the adult male.

Diagnosis. The adult male has a distinctive cover of long white setae on the legs, pedipalps, lower half of the carapace including the clypeus, and the dorsal opisthosoma ( Figures 2-3 ). The dorsal opisthosoma is marked with a dark 'V' shape, pointed toward the front. The colouration of females varies greatly, from mostly white to white and black or brown. We place M. albus in the anomalus group within the genus

Maratus , along with M. anomalus and M. vultus . In all three species the apex of the outer ring of the embolus of the male pedipalp is blunt and bifurcated.

Description of male ( Figures 2-6 ). Males from Eyre Bird Observatory (N=7) ranged from 3.32 to 4.18 mm in length. Males from Kangaroo Island (N=3) ranged from 3.73 to 4.20 mm in length. One male from Port Lincoln was 3.56 mm in length. The chelicerae are black and glabrous. Long, dense white setae extend from the lower sides of the carapace to cover the clypeus, where they extend over the proximal part of

each chelicera. In front, this field of white setae extends from the AME to the chelicerae. In front, the pedipalps are also covered with these long white setae. On the sides of the carapace, the white setae are oriented upward, separate from a relatively narrow marginal band of shorter white setae. The top half of the carapace, including the eye region and areas surrounding the eyes, has a uniform cover of brown to red-brown setae. A more or less distinct lateral band of white scales extends behind each PLE, in some cases extending to the rear margin of the carapace. The PME are closer to the PLE than to the ALE.

The dorsal plate of the opisthosoma is also covered with long, white setae, except for dark areas at the center that tend to take the form of a 'V' pointed to the front. Some males from Kangaroo Island had brown scales in these dark areas ( Figure 3 :7-12). Long, stout white setae extend forward from the anterior margin of the opisthosoma, and long white setae also cover the sides of the opisthosoma. The

underside of the opisthosoma is brown with black lateral stripes ( Figure 6 :3). The sternum bears long white setae to the rear, but is otherwise dark and glabrous. The endites are dark and glabrous. The legs are generally brown with many long white setae. Legs I and II are shorter than legs III and IV, and legs III are by far the longest. As viewed from the front the distal patella and femur of each leg III is black with a prominent ventral fringe of black setae. The proximal femur, and the metatarsus and tarsus are covered and fringed with long white setae. In many males the cover of long white setae on legs I, II, and IV, as well as the fringe of white setae of the anterior femur III, is very well developed ( Figure 2 :11). The pedipalps ( Figure 5 ) are typical for Maratus in most respects. The two apices of the embolus are well-developed. The inner apex is shorter, thinner, and pointed. The outer apex is longer and thicker, and is bifurcated and flattened at the tip.

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Description of female ( Figures 7-10 ). Females from Eyre Bird Observatory (N=3) ranged from 4.39 to 4.53 mm in length. Females from Kangaroo Island (N=2) ranged from 4.83 to 5.86 mm in length. Adult females are highly variable in appearance, from white to white and black to brown, but share many features with adult males. They have many long, white setae covering the lower sides of the carapace and

the clypeus. Their chelicerae are dark brown and glabrous but not black as in the males. They also have wide lateral bands of white setae extending to the rear behind the PLE. In some individuals off-white or brown setae are mixed with the white setae, and as with the males the females from Kangaroo Island ( Figure 8 ) tend to have many more brown setae. The eye region has a covering of white (Eyre Bird Observatory) to brown (Kangaroo Island) setae. The PME are almost equidistant between the ALE and the PLE. Directly behind the eye region, between the lateral bands, the carapace is dark brown or black. Although the long white scales that cover the sides of the carapace extend almost to the margin, there is no distinct marginal band as in the males. The dorsal opisthosoma has a covering of white or brown setae and often (but not always) has a prominent, dark central figure that varies greatly in shape and appearance ( Figures 7-8 ). Several pairs of white or brown spots may be present along the margins of this dark region, or embedded in a uniform cover of brown setae. The ventral opisthosoma is covered with shorter white or brown setae, and a pair of indistinct, dark lateral stripes may be present. The coxae, sternum, and endites are translucent white or brown, with a fringe of white setae around the margins of the sternum.

All four legs, and the pedipalps as viewed from the front, are covered with white or light brown setae, interrupted by a dark, more or less distinct ring at each joint. Legs I and II are shorter than legs III and IV, and leg III is the longest. The epigynum ( Figure 9 : 13-16) varies greatly with respect to the relative size of the fossae (fenestrae) and posterior spermathecae, and the separation of the fossae (wide to very narrow

septum). Between each fossa and each spermatheca a pair (lateral and medial) of heavily sclerotized ducts of variable width can be seen.

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Immatures ( Figures 11-12 ). Immature Maratus albus , like adult females, have many long white setae on the legs and sides of the carapace, with no marginal band, and with red-brown to black markings on the dorsum and around the eyes. Even the second (emergent) instars have these setae ( Figure 11 :1-3).

Courtship display ( Figures 13-15 ). The display of a male Maratus albus in front of a sighted female was observed in a simulated natural setting in the laboratory. This display is relatively simple, consisting of assymetric semaphore signalling with extended legs III, slightly flexed at the patellar-tibial joint. From a symmetrical position with both legs held upright, the leg III of one side is first lowered to a horizontal

position in several discrete steps, then returned to an upright position in several discrete steps. Then the opposite leg III is moved in the same manner, lowered and then raised in several discrete steps. This alternating leg III semaphore may be continued through a series of cycles (one cycle: left down, left up, right down, right up) of 2-3s duration. The opisthosoma is not raised or displayed to the female during this display.

As noted for other Maratus , a female may indicate rejection of a male by rearing and waving her abdomen. Two females that engaged in this behaviour mated with males in subsequent encounters.

Jumping. As do other Maratus , M. albus power their jumps primarily through extension of their legs III ( Figure 16 ).

Habitat and distribution. Localities where Maratus albus was found are shown in Table 1 and on the map ( Figure 1 ). These spiders were found on low coastal vegetation, along beach paths running through sand dunes (Eyre Bird Observatory, Figure 17 :1), on a sandy beach (D’Estrees Bay, Kangaroo Island), or on rocky terrain (Flinders Chase NP, Kangaroo Island, Figure 17 :2).

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 2. Four adult male Maratus albus types from Eyre Bird Observatory. 1 - 4, Holotype.

Figure 3. Nine adult male Maratus albus from Eyre Bird Observatory (1 - 6) and Kangaroo Island (7 - 12).

Figure 4. Four adult male Maratus albus from Eyre Bird Observatory in alcohol. 1 - 4, Holotype.

Figure 5. Medial to lateral views of the left pedipalp of five adult male Maratus albus from Eyre Bird Observatory, all types. 1 - 5, Holotype.

Figure 6. Frontal views of two adult male Maratus albus from Eyre Bird Observatory in alcohol (1 - 2), and ventral view of living male M. albus (3).

Figure 7. Six female Maratus albus from Eyre Bird Observatory.

Figure 8. Four female Maratus albus from Kangaroo Island. Observatory (Figure 7), these had many more brown setae.

Figure 9. Female Maratus albus in alcohol. 13 - 16, Epigyna of four females.

Figure 10. Ventral views of three female Maratus albus. 3, This female had a deformed right rear leg.

Figure 11. Immature Maratus albus, offspring of spiders collected at Kangaroo Island. 1 - 2, Second or emergent instar. 3, Different second instar with more red-brown colouration of the legs and dorsal markings. 4 - 6, Three views of an older immature M. albus.

Figure 12. Views of three different immature Maratus albus, offspring of spiders collected at Kangaroo Island.

Figure 13. Series of positions assumed by the holotype male Maratus albus (♂ # 1) during courtship of a female.

Figure 14. Courtship display positions of five different male Maratus albus from Eyre Bird Observatory.

Figure 15. Selected frames from a 25 fps video showing sequential positions held during the display of a male Maratus albus.

Figure 16. Three different male Maratus albus preparing to jump (1 - 2), or just after take-off (3). 1 - 2, Note the elevation of legs I and II and the flexion of legs III in preparation for a jump. 3, In this more vertical jump, legs III are shown in a completely extended position just after take-off.

Figure 17. Coastal vegetation at Eyre Bird Observatory (1) and Flinders Chase NP, Kangaroo Island (2).