Cybaeota wesolowskae, Marusik & Omelko & Koponen, 2020

Marusik, Yuri M., Omelko, Mikhail M. & Koponen, Seppo, 2020, On two enigmatic spiders (Araneae: Cybaeidae & Phrurolithidae) from the Russian Far East, Zootaxa 4899 (1), pp. 247-258 : 248-253

Cybaeota wesolowskae sp. nov.

Figures 1 A–G, 2A–H, 3A–H, 4A–B, 5A–E

Etymology. This species is named after Wanda Wesołowska, honouring her great contribution to arachnology and to the taxonomy of Salticidae in particular, and on the occasion of her 70 th birthday.

Diagnosis. The male of the new species is most similar to those of C. calcarata (Emerton, 1911) by having a meandering sperm duct on the embolic base and by the shape of the anterior arm of the conductor, but differs from it by having a claw-like posterior arm of the conductor (vs. square), and a square-shaped anterior part of the anterior arm of the conductor protruding anteriorly (vs. rounded and not protruding). The epigyne of C. wesolowskae sp. nov. is also similar to that of the generotype and differs by the more widely spaced receptacles (ca. by ¼ of receptacle diameter vs. by less than ½ of the radius). The epigyne of C. wesolowskae sp. nov. is somewhat similar to that of C. munda Chamberlin & Ivie, 1937 , C. nana Chamberlin & Ivie, 1937 and C. shastae Chamberlin & Ivie, 1937 by the more widely spaced receptacles, but differs from these three species by the more posteriorly located fovea.

Description. Male (Holotype). Total length 2.17. Carapace 1.06 long, 0.79 wide. Prosoma light coloured; carapace without pattern. Carapace with small longitudinal, almost indistinct fovea; with very few setae on thoracic part, represented by median row with ca 5 setae; eyes subequal in diameter (ca 0.09), except for AME (ca. 0.06), contiguous except PME which are separated by about one radius; clypeus height equal to eye diameter. Sternum without pattern, with slightly darker margins, covered by setae. Chelicerae relatively short ( Fig. 1F ), with distinct mesal (Mr) ridge, 3 promarginal and 4 retromarginal teeth, all teeth small; setae on anterior surface near fang with globose bases. Maxillae and labium of subequal width, maxillae converging, 2 times longer than labium, maxillae 1.2 times longer than wide.

Legs uniformly coloured, relatively long (leg I greater than 3 times longer than carapace), with conspicuous pairs of ventral tibial and metatarsal spines on legs I–III, spines with locking mechanisms (Ls); femur I with 1 one prolateral spine with locking mechanism. Leg III with unpaired ventral spine.

Abdomen oval, 1.5 times longer than wide, with distinct dorsal pattern and less distinct ventral pattern ( Figs 1A, B ); booklungs light-coloured.

Palp. Femur unmodified, ca 2.8 times longer than wide, subequal in length to patella+tibia; patella unmodified, about 1.3 times shorter than tibia; tibia with 2 retrolateral apophyses, flat anterior one (Ra) flattened, wider than long, and claw-like posterior one (Rp); anterior apophysis located on distal part, wider than long. Cymbium droplet-shaped, lacking folds, 1.7 times longer than wide and 2.8 times longer than deep; tip slightly longer than 1/3 of cymbial length; distinct spines absent, setae on tip stronger than those on other parts. Bulb oval, 1.25 times longer than wide; subtegulum (St) located antero-prolaterally; tegulum with 2 appendages, embolus (Em) and complex conductor (Co); sperm-duct long, extending along tegulum edge, smoothly rounded, undulating near base of embolus. Conductor weakly sclerotized, only part of it visible in light microscopy, with 2 arms standing on joint stem (Cs) originating near base of embolus and directed posteriorly, anterior arm (Aa) truncate, square-shaped, posterior section bipartite with sharply pointed tip directed posteriorly and posterior arm (Pa) small, well-sclerotized, with bluntly pointed, anteroventrally directed tip. Embolus claw-like, originating at 12 o’clock and directed posteriorly, broad basally and tapering towards tip, slightly twisted around its axis.

Female (Paratype). Total length 2.45–2.80. Carapace 1.00–1.04 long, 0.77–0.84 wide. General appearance as in male. Palpal tarsus without claw. Integument of tibia covered with sparse scale-like structures (Ss) and transverse wrinkles; femur with smooth integument and scale structures, metatarsus with numerous deep transverse wrinkles. Paired claws of tarsus with ca. 7 teeth, unpaired claw with 3 teeth. Leg lengths as shown in Table 3. Spination ( Table 4) differs from that of male, ventral spine in tibia III present.

Spinnerets relatively large, spinneret field wider than ½ of abdomen width near spinnerets; anterior lateral spinneret thicker than tibia IV; colulus reduced to 2 setae.

Epigyne as in Figs 3G, H ; simple, covered with plumose setae, weakly-sclerotized, receptacles and copulatory ducts clearly visible through integument; wider than long, with central fovea; fovea with distinct anterior hood slightly wider than receptacle radius, fovea posteriorly rebordered in some specimens; copulatory openings located in hood and not visible, copulatory ducts short, about half of receptacle radius; receptacles large, globular, separated from each other.

Type material. Holotype ³ and paratype ♀: RUSSIA: Maritime Province: ca 30 km E of Ussuriysk, Kamenushka Vill. , 43°36.45'N, 132°13.60'E, leg. S.Y. Storozhenko, 30.VIII.2001 (bark spraying) ( ZMMU).

Paratypes: RUSSIA: Maritime Province: Chuguyevka Field Station , ca. 43°50'N, 134°15'E, leg. S. Koponen, 31.VII–5.VIII.1998, 2♀ ( ZMUT) ; Lazo District, Korpad’ Camp , 43°16'N, 134°08'E, leg. S. Koponen, 6–9.VIII.1998, 1♀ ( ZMUT) ; Pravaya Izvilinka River , 43°55'N, 134°23'E, leg. Y.M. Marusik, 1–2.VIII.1998, 1♀ ( ZMMU) ; Same data as holotype, leg. Y.M. Marusik, 29.VIII.2001, 1♀ ( ZMMU) .

Habitats. This species was collected either by bark spraying with repellent or in forest litter.

Distribution. All records of this species are from the South part of the Maritime Province.

Remarks. There are several families of spiders occurring in the southeastern Palaearctic (NE China, Korea, Japan, and the southern part of Russian Far East) and the Nearctic, but most of them also occur in the western Palaearctic (e.g., Atypidae , Ctenidae ( Anahita Karsch, 1879 ), Cybaeidae , Leptonetidae , Nesticidae , Oonopidae and Theridiosomatidae ) and have a disjunction in Central Asia, Mongolia and Siberia ( Marusik & Kovblyuk 2011). However, one family has a similar distribution to Cybaeota : Antrodiaetidae are known from the Nearctic and southeast Palaearctic only. Its type genus, Antrodiaetus Ausserer, 1871 , is represented in Asia by two species in Japan and 12 in the United States ( WSC 2020). Another family, Hypochilidae , displays a similar distributional pattern: its type genus, Hypochilus Marx, 1888 , is represented by 10 species in North America and two species of another hypochilid genus, Ectatosticta Simon, 1892 , are known from China. The micronetine genus Arcuphantes Chamberlin & Ivie, 1943 (Linyphiidae) also displays a similar range, with 12 species known in the Nearctic and another 39 in Far East Asia. It is likely, however, that the Asian and American species are not congeneric.

The apparent distribution of Cybaeota is a little bit unusual: only one species has been found in Asia (and only in the Russian part of the southeastern Palaearctic) and the genus is unknown in adjacent China, Korea or Japan.

A review of other groups of arthropods reveals that a similar distribution pattern is not uncommon among other arachnids and insects. A peculiar genus of harvestmen, Caddo Banks, 1892 (Caddidae) , has two species, C. agilis Banks, 1892 and C. pepperella Shear, 1975 , both of which are known in Sakhalin, Japan, and across the United States. The mite genus Yachatsia Cook, 1963 (Hydrachnidae) ( Abé 2019), cockroach genus Cryptocercus Scudder, 1862 (Cryptocercidae) ( Maekawa & Nalepa 2011), orthopteran genera Atlanticus Scudder, 1894 and Sphagniana Zeuner, 1941 (Tettigoniidae) (Storozhenko, pers. comm.), and homopteran genus Pagaronia Ball, 1902 (Cicadellidae) (Dmitriev, pers. comm.) have amphi-Pacific disjunctive ranges and do not occur in the more northern parts of the Pacific Region.

Figures

FIGURE 1. Cybaeota wesolowskae sp. nov. A–B Male habitus, dorsal and ventral; C–D Female habitus, dorsal and ventral; E–F Prosoma, frontal, female and male; G Female, leg I prolateral. Scales = 0.1 mm (E, F) and 0.2 mm (G). Abbreviations: Uv—unpaired ventral spine.

FIGURE 3. Cybaeota wesolowskae sp. nov. A–D Male palp, ventral, retrolateral, dorsal and prolateral; E Male prosoma, antero-ventral; F–G Epigyne, dorsal and ventral. Scales = 0.2 mm.