Mesiotelus lubricus ( Simon, 1880 )

Fu, Jianying, Zhang, Feng & Zhu, Mingsheng, 2008, Redescription of a little-known spider species, Mesiotelus lubricus (Simon, 1880) (Aranei: Liocranidae) from China, Arthropoda Selecta 17 (3), pp. 169-173 : 171-173

Mesiotelus lubricus ( Simon, 1880)

Figs 1—13 .

Liocranum lubricum Simon, 1880: 122 , pl. 3, f. 26—27(♂♀).

Mesiotelus lubricus: Simon, 1897: 140 , 143; Song & Hubert, 1983: 14, f. 37—40(♂ ♀); Song, 1987: 328, f. 283(♂♀); Song et al., 1999: 411, f. 238M—N(♂ ♀); Song et al., 2001: 304, f. 193(♂♀).

TYPE MATERIAL. Liocranum lubricum Simon, 1880 : the type specimens are deposited in the Natural History Museum of Paris. They were examined by Prof. Daxiang Song (ca. 1979) and we consulted his original sketches.

MATERIAL EXAMINED. 1 ♂ and 8 ♀♀ from Baishi Mountain , Laiyuan County, Hebei Province, China, April 30, 2008, F. Zhang and L.M. Zhu leg. ( MHBU) . 1 ♀ from Pingshan County, Hebei Province, China, May 21, 1986, W. S. Zhang leg. ( MHBU) .

3 ♀♀ from Zanhuang County, Hebei Province, China, June 13, 1998, F. Zhang leg. ( MHBU) . 2 ♀♀ from W u’an County, Hebei Province, China, May 18, 1999, F. Zhang leg. ( MHBU) . 2 ♀♀ from Linzhou County, Henan Province, China, May 11, 1999, F. Zhang leg. ( MHBU)

DIAGNOSIS. This species resembles the type species M. tenuissimus [cf. Kovblyuk et al., 2008], but males can be distinguished by the longer thumb-shaped retrolateral tibial apophysis (retrolateral view), by the palpal tibia bearing a dorsal knob-shaped apophysis proximally, by the shape of additional tegular apophysis, by the relatively thin base of median apophysis; females by the posterior margin of epigynal scape being closer to genital fold.

REDESCRIPTION. Male (Mt. Baishi, Hebei Province). Total length 3.72: carapace 1.55 long, 1.42 wide; abdomen 2.17 long, 1.32 wide. Carapace ( Fig. 1 ) brown and smooth, without granulations or pits, elongate-ovoid in dorsal view, darker in eye area. Clypeus height 0.10, almost equal to AME diameter. Eye sizes and interdistances: AME 0.10, ALE 0.12, PME 0.10, PLE 0.10; AME—AME 0.16, AME— ALE 0.13, PME—PME 0.19, PME—PLE 0.19, ALE—PLE 0.16. MOA 0.19 long, front width 0.13, back width 0.19. Thoracic groove longitudinal, dark. Radial furrows indistinct, slightly dark. Chelicerae ( Fig. 3 ) brown, with three promarginal and two retromarginal teeth. Endites ( Fig. 2 ) brown, nearly rectangular, obliquely depressed, inner margin with a cluster of fine hairs. Labium ( Fig. 2 ) as long as wide, with several long bristles distally. Sternum ( Fig. 2 ) bright brown, posteriorly rounded between coxae IV. Legs brown; femur I with two dorsal and one prolateral macrosetae, tibia I with two pairs of long spines and two rows of short spines ventrally, metatarsus I with one pair of long spines ventrally; femur II with two dorsal macrosetae, tibia II with two pairs of long spines (prolateral spines longer) and two rows of short spines ventrally, metatarsus II with one pair of long spines ventral; femur III with two dorsal, one prolateral and one retrolateral macrosetae, tibia III with three pairs of ventral spines, two prolateral spines and one retrolateral spine; metatarsus III with one pair of ventral, one prolateral and one retrolateral spines; other segments have no spines, leg IV absent. Tarsal claws with four teeth. Measurements of legs: I 7.78 (1.13 + 1.80 + 2.07 + 0.78 + 2.00); II 6.58 (1.07 + 1.58 + 1.61 + 0.55 + 1.77); III 5.38 (0.65 + 1.32 + 1.35 + 0.61 + 1.45). Abdomen ( Fig. 1 ) light brown dorsally, with two pairs of muscle impressions centrally and behind these, four white chevrons; paler ventrally and with white ring around spinnerets.

Male palp ( Fig. 10 ) very long: femur 0.78, patella 0.61, tibia (including apophysis) 0.84, tarsus (cymbium) 0.78. Palpal organ as illustrated ( Figs 10—13 ): tibia with short prolateral lobe [ Bosselaers & Jocque, 2002] and longer thumb-shaped retrolateral apophysis terminally, and also with a dorsal knob-shaped apophysis proximally ( Fig. 11 ); median apophysis ( Fig. 12 ) retrolaterally, long flake-like and with thin base, brown, originating from tegulum centrally; additional tegular apophysis ( Fig. 12 ) apically, brown and sclerotized, large and almost triangular from ventral view, with two pointed spine-like tips; embolus long, originating prolaterally, median part hidden behind additional tegular apophysis, tip near conductor; conductor apical, white, membranous ( Figs 12—13 ), thin and flake-like; subtegulum small, almost hidden by tegulum, prolateral.

Female (Mt. Baishi, Hebei Province). Total length 5.76: Carapace 2.16 long, 1.80 wide; abdomen 3.60 long, 2.25 wide. Eye sizes and interdistances: AME 0.13, ALE 0.14, PME 0.12, PLE 0.12; AME—AME 0.07, AME—ALE 0.03, PME-PME 0.13, PME-PLE 0.13. MOA 0.33 long, front width 0.30, back width 0.36. Clypeus height 0.13. Legs brown; femora I, II with two dorsal and one prolateral macrosetae ( Fig. 5 ), tibiae I, II with two pairs of long and two rows of short spines ventrally, metatarsi I, II with one pair of ventral spines ( Fig. 7 ); femora III, IV with two dorsal, one prolateral and one retrolateral macrosetae ( Fig. 4 ), tibiae III, IV with three pairs of ventral spines, two prolateral spines and one retrolateral spine; metatarsi III, IV with three pairs of ventral spines, one prolateral spine and one retrolateral spine ( Fig. 6 ); other segments have no spines. Measurements of palp and legs: palp 3.05 (0.86 + 0.66 + 0.72 + 0.81); I 8.29 (2.16 + 1.10 + 2.19 + 1.76 + 1.08); II 7.66 (2.03 + 1.07 + 1.90 + 1.67 + 0.99); III 7.03 (1.76 + 0.99 + 1.40 + 1.89 + 0.99); IV 9.99 (2.61 + 1.12 + 2.30 + 2.79 + 1.17). Leg formula: 4123.

Epigynum as illustrated ( Fig. 8 ), with almost triangular hairy plate; plate with pronounced, half-moon shaped hood anteriorly; with several transverse wrinkles centrally; copulatory openings concealed at sclerotized lateral margins; tongue-shaped epigynal scape posteriorly, close to genital fold. Vulva ( Fig. 9 ) with very short copulatory ducts connected to copulatory openings and spermathecae; spermathecae posteriorly, both ball-shaped, sp1 larger than sp2 and sp1 fitted with single membranous fertilization duct.

VARIATION. Females (n=15): body length: 4.94-6.32. Femur I prolateral spine: 0-1; femur II prolateral spines:1-2; femur III, IV retrolateral spines:1-2, prolateral spines:1-2.

HABITIAT. Free-living ground-dwelling spiders inhabiting deciduous forest litter, debris, or humus on the shady temperate forest floor. All specimens were collected using a hand-made detritus sifter on forest litter.

DISTRIBUTION. China (Hebei, Henan, Beijing).

Figures

Figs 1 - 7. Mesiotelus lubricus: 1 — male body, dorsal view; 2 — male endites, labium and sternum, ventral view; 3 — male left chelicera, posterior view; 4 — female left femur IV, dorsal view, showing spines; 5 — female left femur I, dorsal view, showing spines; 6 — female left tibia and metatarsus IV, ventral view, showing spines; 7 — female left tibia, metatarsus and tarsus I, ventral view, showing spines; TI — tibia; M — metatarsus. Scale bars: 1 — 2 mm; 2 — 1 mm; 3 — 0.5 mm; 4 - 7 — 0.1 mm.

Figs 8 - 13. Mesiotelus lubricus: 8 — epigynum, ventral view; 9 — vulva, dorsal view; 10 — male left palp, showing palpal organ, tibia and patella; 11 — male left palp, prolateral view; 12 — same, ventral view; 13 — same, retrolateral view; AA — additional tegular apophysis; C — conductor; CO — copulatory opening; DTA — dorsal tibial apophysis; E — embolus; FD — fertilization duct; ES — epigynal scape; H — hood; MA — median apophysis; P — patella; PL — prolateral lobe of tibia; RTA — retrolateral tibial apophysis; SD — sperm duct; SP 1 — spermatheca with fertilization duct; SP 2 — spermatheca without fertilization duct; ST — subtegulum; T — tegulum; TI — tibia. Scale bars: 8 - 9 — 0.3 mm; 10 — 1 mm; 11 - 13 — 0.5 mm.