Table Of Content

A new turreted spider of the genus Arkys (Araneae: Arkyidae) from Tasmania John C Douglas Queen Victoria Museum and Art Gallery, 2 Invermay Road, Invermay, Launceston Tasmania 7248 A new turreted spider of the genus Arkys (Araneae: Arkyidae) from Tasmania. Record of the Queen Victoria Museum and Art Gallery No. 118. Abstract The specimen described below is not just a new species (Arkys enigma sp. nov.) but mixes the characters of Arkys Walckenaer, 1837 and the presumed sister genus Demadiana Strand, 1929; thus, it is thought to be the sister group of all other Arkys species and challenges the separation of Arkys and Demadiana. Several characters in the female support this challenge. The overall shape of the epigyne of Demadiana is trapezoidal whereas it is triangular in all known Arkys; and in Arkys enigma sp. nov., it is trapezoidal. The anterior margin of the carapace on Demadiana is convex or straight whereas in Arkys enigma sp. nov., the anterior edge is concave as for most Arkys species which are either concave or straight. Finally, Arkys enigma features leaf-shaped setae on the carapace. These setae are on a globular socket on the surface but unlike Demadiana setae, which have a globular socket within a setal pit. The abdominal setae are also in surface globular sockets, but are attenuate. 3 Introduction An image of an unidentified spider of the it was clear that the photograph and specimen Arkyinae (Fig. 1) was sent to me some years were the same species. The biggest difference ago by a British naturalist travelling through between the two spiders was the location. the Tarkine region of north-west Tasmania. The preserved specimen was collected from All attempts to identify the species from the east coast of Tasmania, diametrically published descriptions were thwarted and it opposite to the photographed specimen. became an item in my wish list. After many In the photograph, there is a prominent medial months, I was examining spiders in the process on the dorsal surface of the abdomen QVMAG collection and discovered a which is not as well formed on the preserved specimen which closely resembled the spider specimen. in the photograph. On closer inspection, . Figure 1 Arkys enigma, sp. nov., (a and b) habitus. Photographs by Jonathan McGowan (used with permission) from the Julius River reserve, Arthur River, West Tasmania; (c) Arkys enigma, sp. nov., female from Douglas River, eastern Tasmania, dorsal view; (d) ventral view, epigyne removed. Scale bars: 1.0 mm. 4 Arkys has had a diverse history. The genus Archemorus multituberculatus, Archemorus was raised by Walckenaer in 1837 with occidentalis, Archemorus roosdorpi, Archemorus the description of A. lancearius. The genus semicirculatus, Archemorus sibil, Archemorus Arcys was placed in the family Araneidae soosi, Archemorus transversus, Archemorus and remained there until Heimer (1984) tuberculotus and Archemorus vicarius; placed the genus in Mimetidae. Subsequently Chrysanthus (1971) as Archemorus roosdorpi Davies (1988) transferred the genus to and Archemorus sibil; Mascord (1968) as Tetragnathidae. Scharff and Coddington Neoarchemorus speechleyi; Rainbow (1920) (1997) then transferred the genus to as Archemorus cicatricosus; Reimoser (1936) Araneidae, where it remained until Dimitrov as Archemorus toxopeusi and Archemorus et al. (2017) elevated the group to family occidentalis; Simon (1893) as Archemorus rank of Arkyidae. Several species were simsoni, Arkys perl at us and Archemorus originally described by Balogh (1978) curtulus; Urquhart (1891) as Aerea alticephal. as Archemorus coronatus, Archemorus dilatatus, These genera are all in synonymy with Arkys Archemorus furcatus, Archemorus grandis (Framenau. et al., 2010). Archemorus latissimus, Archemorus montanus, Method Digital photographs of living specimen were Drawings of setae and spination are by the taken with a Sony DSC-H20 camera. Other author. All measurements are in millimetres. digital images were taken with a Nikon D750 Abbreviations used in the text are as follows: camera mounted on a Nikon SMZ 1000 ALE anterior lateral eye; AME anterior median microscope. Image stacking was produced eye; PLE posterior lateral eye; PME posterior using Photoshop software. median eye; MOQ median ocular quadrangle. Arkys Enigma, sp. nov. MATERIAL EXAMINED Australia. Holotype Unlike all other Arkys and Demadiana species, Female, Douglas River, eastern Tasmania, which have similar setae and the setae on the (41° 47' S, 148° 15' E). T. McManus, 4 May dorsal abdomen are normal, hair-like setae, 1992, QVM:13:6000. A. enigma features leaf-shaped setae which lie parallel to the surface of the carapace. The ETYMOLOGY The species epithet is a noun male is unknown. The epigyne shows similarity in apposition from the problem it caused, an to Demadiana simplex Framenau et al., 2010, enigma. The spider has been recorded from but has no similarities to any Arkys species opposite sides of Tasmania, the epigyne has shown in Balogh (1978) or Heimer (1984a). similarities to Demadiana, but the eyes are DESCRIPTION Holotype Female, QVM:13:6000 similar to Arkys and the setae on the carapace Dimensions: (mm): Total length (excluding are dissimilar to any other setae. chelicerae) 12.9. Carapace length 4.2, width 4.1. Abdomen length 8.7, width 9.9. DIAGNOSIS Closely related to A. coronatus Pedipalp: femur 1.20, patella 0.38, tibia 0.57, (Balogh, 1978) (known only from a juvenile metatarsus 0.57, tarsus 0.48, total 3.20. from Papua New Guinea) in the abdominal Leg I: femur 2.75, patella 1.82, tibia 3.04, shape and pattern; however, it differs in the metatarsus 2.07, tarsus 1.28, total 10.96. very low caput and that the posterior median Leg II: femur 3.02, patella 1.50, tibia 2.49, eyes are not on tubercles. It also has metatarsus 1.86, tarsus 1.10, total 9.97. similarities in shape to A. multituberculatus Leg III: femur 2.28, patella .79, tibia 1.31, (Balogh, 1982). A. enigma has pronounced metatarsus 0.68, tarsus 0.90, total 5.96. tubercles which accommodate the lateral Leg IV: femur 4.01, patella 1.58, tibia 2.57, eyes as with other Arkys species by comparison metatarsus 2.04, tarsus 0.85, total 11.05. 5 Figure 2. Arkys enigma, sp. nov., (a) carapace; (b) eyes and chelicerae; (c) sternum; (d) spinnerets. Scale bars: 1.0 mm. CARAPACE (Fig. 2a) EYES (Fig. 2b) Reddish brown. Leaf-shaped setae in globular Sizes: AME, 0.25; ALE, 0.24; PME, 0.40; sockets densely clustered laterally, reducing PLE, 0.24. centrally and missing along distal margin. Interspaces: AME-AME, 0.40; AME-ALE, 1.40; PME-PME, 0.69; CHELICERAE (Fig. 2b) PME-PLE, 1.49; PLE-ALE, 0.24. MOQ Light brown. width front 0.62; MOQ width back, 1.04; STERNUM (Fig. 2c) MOQ length, 1.15; eye group width 3.62. Light brown; as long as wide, with narrow Both ALE and PLE on extended tubercles distal protrusion. curving forward from centre line of carapace. 6 Figure 3. Arkys enigma, sp. nov., (a) abdomen, dorsal view; (b) oblique view of abdomen showing central turret; (c) epigyne, ventral view; (d) epigyne, dorsal view. ABDOMEN EPIGYNE (Fig. 3c and 3d) (Fig. 3a) Heart-shaped, maroon with yellow Ventral view: trapezoidal. Dorsal view: margins, except anteriorly. Centrally domed transversely wide rectangular in overall shape; (Fig. 3b); margins with five serrations plus median scape inverted T-shaped with broad posterior protrusions. Attenuate setae lateral furrows flanked by rounded ridge. anteriorly on globular sockets not pitted. (Fig. 5b and 5d) Spinnerets (Fig. 2d) with cylindrical spigots as shown in Murphy and Roberts (2015: pi. 107). 7 Figure 4. Arkys enigma, sp. nov., (a) Tibia and metatarsus I: (b) tibia and metatarsus II. Scale bars: 1.0 mm. LEGS (Fig 4) Yellow, leg I banded red on femur and tibia Spination: I: tibia, 9; metatarsus 7. II: tibia, 9; metatarsus, 6. Figure 5. Arkys enigma, sp. nov., (a and c) setae on carapace set on globular sockets; (b and d) attenuate setae on abdomen set on globular sockets. 8 Distribution Arkys enigma is known from the holotype and photographic evidence of it from from Douglas River, eastern Tasmania western Tasmania. Acknowledgements I am grateful to Dr Robert Raven for his The support and encouragement given by mentoring through the process of describing David Maynard, Curator, Natural Sciences a spider. The photographs of the live spider and Simon Fearn, Collections Officer, Natural were taken by Jonathan McGowan and used Sciences at the Queen Victoria Museum, here with his permission. Launceston, is much appreciated. References Balogh, P 1978, 'New Archemorus species Mascord, RE 1968, 'A new genus and species (Araneae: Argyopidae)', Acta Zoologica of spider (Araneida: Argiopidae)', Journal Hungarica, vol. 24, no. 1, pp. 25. of the Entomological Society of Australia, New South Wales, vol. 4, pp. 10-14. Chrysanthus, P 1971, 'Further notes on the spiders of New Guinea I (Argyopidae)', Murphy, JA and Roberts, MJ 2015, 'Spider Zoologische Verhandelingen, vol. 113, no. 1, families of the world and their spinnerets', pp. 52. British Arachnological Society, York, vol. 1 and 2, pp. i-xii, 1-189; xiii-xvi, 191-353. Davies, VT 1988b, 'An illustrated guide to the genera of orb-weaving spiders in Rainbow, WJ 1920b, 'Arachnida from Lord Australia', Memoirs of the Queensland Howe and Norfolk Islands', Records of the Museum, vol. 25, pp. 273-332. South Australian Museum, vol. 1, pp. 229-272. Dimitrov, D, Benavides, LR, Arnedo, MA, Reimoser, E 1936, 'Fauna Buruana. Giribet, G, Griswold, CE, Scharff, N and Arachnoidea', Treubia, vol. 7 (Suppl.), Hormiga, G 2017, 'Rounding up the usual pp. 405-413. suspects: a standard target-gene approach Scharff, N and Coddington, JA 1997, for resolving the interfamilial phylogenetic 'A phylogenetic analysis of the orb-weaving relationships of ecribellate orb-weaving spider family Araneidae (Arachnida, spiders with a new family-rank classification Araneae)', Zoological Journal of the Linnean (Araneae, Araneoidea)', Cladistics, vol. 33, Society, vol. 120, pp. 355-434. no. 3, pp. 221-250 and Suppl. Simon, E 1889, 'Etudes arachnologiques. Framenau, V, Scharff, N and Flarvey, MS 21e Memoire. XXXII. Descriptions d'especes 2010, 'Systematics of the Australian et the genres nouveaux de Nouvelle orb-weaving spider genus Demadiana with Caledonie', Annales de la Societe comments on the generic classification of the Entomologique de France, vol. 6, no. 8, Arkyinae (Araneae : Araneidae)', Invertebrate pp. 237-247. Systematics, vol. 24, pp. 139-171. Simon, E1895, 'Histoire naturelle des Heimer, S 1984, 'Remarks on the Spider araignees', Paris, vol. 1, pp. 761-1084. Genus Arcys Walckenaer, 1837, with Description of New Species (Araneae, Simon, E1903, 'Descriptions Mimetidae)', Entomologische Abhandlungen, d’arachnides nouveaux', Annales de la Societe Staatliches Museum fur Tierkunde Dresden, Entomologique de Belgique vol. 47, pp. 21-39. vol. 47, pp. 155-178. 9