Araeoncus hyalinus, Song & Li, 2010

Song, Yanjing & Li, Shuqiang, 2010, The spider genera Araeoncus Simon, 1884 and Diplocephalus Bertkau, 1883 (Arachnida, Araneae, Linyphiidae) of China, Zoosystema 32 (1), pp. 117-137 : 120-125

publication ID	https://doi.org/ 10.5252/z2010n1a6
DOI	https://doi.org/10.5281/zenodo.4549311
persistent identifier	https://treatment.plazi.org/id/EA079A4C-FFCE-F921-FF0B-7EDE0A72FBEE
treatment provided by	Felipe
scientific name	Araeoncus hyalinus
status	sp. nov.

Treatment

Araeoncus hyalinus View in CoL n. sp.

( Figs 1-3 View FIG View FIG View FIG )

TYPE MATERIAL. — Holotype: China, Yunnan Province, Dêqên Zangzu Zizhizhou, Shangri-La County, Bitahai Nature Reserve , 27.83°N, 99.96°E, 15.VI.2006, coll. Y. Song, Z. Cui & J. Xu, ♂ ( MNHN). GoogleMaps

Paratypes: same data as for holotype, 2 ♂♂, 10 ♀♀ ( IZCAS) GoogleMaps ; 1 ♂, 7 ♀♀ (MNHN). — Yunnan Province, Lijiang Naxizu Zizhixian, Yak Lawn Scenic Area , 27.17°N, 100.25°E, 23.VII.2006, coll. Y. Song, Z. Cui & J. Xu, 1 ♂, 23 ♀♀ ( IZCAS). — GoogleMaps Yunnan Province, Lijiang Naxizu Zizhixian, Dragon Spruce Meadow, 27.14°N, 100.23°E, 21.VII.2006, coll. Y. Song, Z. Cui & J. Xu, 1 ♀ ( IZCAS) GoogleMaps .

ETYMOLOGY. — Specific name from the Greek adjective hyalinus = transparent, in reference to the slightly sclerotized embolus which appears transparent.

DISTRIBUTION. — Known from Yunnan and Sichuan provinces, China ( Fig. 12 View FIG ).

DESCRIPTION

Male

Total length 1.54. Carapace 0.80 long, 0.62 wide, raised into a lobe carrying posterior median eyes, and with cephalic pits within the post-ocular sulci, as well as many moderately long hairs scattered within the ocular area ( Fig. 2A, B View FIG ). Clypeus 0.17 high. AME diameter 0.04, ALE 0.06, PME 0.05, PLE 0.05, AME interdistance 0.83 times their diameter, AME-ALE interdistance 1.11 times ALE diameter, PME interdistance 1.38 times their diameter, PME-PLE interdistance 1.38 times PLE diameter. Sternum 0.43 long, 0.44 wide. Coxa IV interdistance 1.11 times their width. Chelicerae with 5 promarginal teeth, 4 retromarginal teeth ( Fig. 2C View FIG ). Tibia I 5.85 times longer than deep. Tm I 0.38, Tm IV absent. Dorsal spines on tibia of leg IV: 2-2-1-1; dorsal spine on patella of leg IV: 1-1-1-1. Leg measurements: I: 2.05 (0.61, 0.18, 0.48, 0.43, 0.36); II: 1.87 (0.54, 0.18, 0.43, 0.40, 0.33); III: 1.55 (0.42, 0.18, 0.31, 0.34, 0.29); IV: 2.05 (0.61, 0.18, 0.50, 0.43, 0.33).

Palp: femur nearly twice long as patella.Tibia with one prolateral apophysis, which is composed of 1 thin S-shaped and 1 thick rhombic sclerite ( Fig. 1A View FIG ); with 1 prolateral and 2 retrolateral trichobothria ( Fig. 1E View FIG ). Paracymbium spiral with terminal part hooked ( Fig. 1D View FIG ). Tegulum distal to subtegulum in unexpanded palp ( Fig. 1B View FIG ). Protegulum vestigial ( Fig. 1C View FIG ). Suprategulum produced into a dentiform marginal apophysis and a bifurcate distal apophysis ( Fig. 2F, G View FIG ), as well as a rectangular extension at the base of the distal apophysis ( Fig. 1C View FIG ). Embolic division ( Fig. 2D, E View FIG ): anterior radical process filmy, pointed obliquely upwards ( Fig. 1B View FIG ); mesal tooth long claviform, pointed distally ( Fig. 2D View FIG ); posterior radical process transparent, elongate with nearly parallel margins but pointed distally ( Fig. 1D View FIG ); embolic membrane long and large, curved to accommodate distal half of the embolus ( Fig. 1B View FIG ); tailpiece narrow basally, strongly broadened to be hunched in the middle, narrowed again towards the end ( Fig. 1C View FIG ).

Female

Total length 1.67. Carapace 0.65 long, 0.52 wide, similar to male in general appearance and coloration, but without cephalic lobe and sulci. Clypeus 0.09 high. AME diameter 0.04, ALE 0.07, PME 0.06, PLE 0.05, AME interdistance 0.50 times their diameter, AME-ALE separation 0.27 times ALE diameter, PME interdistance 0.58 times their diameter, PME-PLE separation 0.56 times PLE diameter. Sternum 0.41 long, 0.43 wide. Coxa IV interdistance 1.65 times their width. Chelicerae with 5 promarginal teeth, 5 retromarginal teeth. Tibia I 5.00 times longer than deep. Tm I 0.35, Tm IV absent. Dorsal spines on tibia of leg IV: 2-2-1-1; dorsal spine on patella of leg IV: 1-1-1-1. Leg measurements: I: 1.79 (0.53, 0.18, 0.41, 0.35, 0.32); II: 1.75 (0.49, 0.18, 0.38, 0.36, 0.34); III: 1.48 (0.44, 0.18, 0.29, 0.29, 0.28); IV: 1.98 (0.59, 0.18, 0.48, 0.38, 0.34).

Epigynum prominent in lateral view ( Fig. 3C View FIG ). Ventral plate with postero-median triangular prolongations separated by a long fissure, anteriorly limited by a rectangular ridge ( Fig. 3B View FIG ). Rectangular dorsal plate totally covered by the ventral plate in ventral view ( Fig. 3A View FIG ). Spermathecae U-shaped; one arm of the “U” is long oblong while the other is small and almost half long the former ( Fig. 3E View FIG ). Copulatory ducts enclosed in a slightly sclerotized capsule, broad and extended with almost parallel margins from copulatory openings, narrowed a bit after turning to the dorsal side, gradually widened again and extended to the ventral side near spermathecae ( Fig. 3D, E View FIG ). The path of copulatory duct is shown in Figure 3E View FIG . Fertilization ducts short, mesally oriented ( Fig. 3E View FIG ).

REMARKS

Araeoncus hyalinus View in CoL n. sp. and A. longispineus View in CoL n. sp. have a conformation closely similar to A. humilis View in CoL (the type species), in having a long coiled and wide, curving ventrally downwards embolus which is unique among the Savignia View in CoL group genera mentioned by Millidge (1977). Embolus of Dicymbium nigrum (Blackwall, 1834) View in CoL (the type species; see Roberts 1987: fig.10c), Diastanillus pecuarius ( Simon, 1884) View in CoL (the type species; see Millidge 1977: fig. 138) and Erigonella hiemalis (Blackwall,1841) View in CoL (the type species; see Roberts 1987: fig. 36a) is spiral and situated at the anterior end of the embolic division.The form of embolus in Alioranus pauper (Simon, 1881) View in CoL (the type species; see Millidge 1977: fig. 128), Diplocephalus foraminifer View in CoL (the type species; see Deltshev 1985: fig. 8) and Glyphesis servulus (Simon, 1881) View in CoL (the type species; see Millidge 1977: fig. 123) is short and obliquely downwards or upwards. As to Saloca diceros View in CoL (O. P.-Cambridge, 1871) (the type species; see Millidge 1977: fig. 132) and Savignia frontata Blackwall, 1833 View in CoL (the type species; see Millidge 1977: fig. 135), their emboli are moderately long, slightly curved, directed backwards or downwards. Besides the form of embolus, both new species are very close to A. humilis View in CoL in the form of anterior radical process (triangular, pointed obliquely upwards), tailpiece (slightly curved upwards), embolic membrane (running along the embolus),distal suprategular apophysis (extended ventrally and curved more or less upwards) and marginal suprategular apophysis (dentiform). The bisected epigynum, U-shaped spermathecae and path of copulatory ducts of vulva (see Wiehle 1960: fig. 124) is similar too. Furthermore, the chaetotaxy (dorsal spines on tibia of leg IV 2-2-1-1, Tm I 0.35-0.43, Tm IV absent) is also closely similar to A. humilis View in CoL (dorsal spines on tibia of leg IV 2-2-1-1, Tm I 0.40-0.42,Tm IV absent; see Wiehle 1960).To sum up, both new species have a basically identical conformation with the type species of the genus Araeoncus View in CoL and hence despite the extra presence of posterior radical process and mesal tooth of embolic division, not present in the other Araeoncus View in CoL species, both species are placed in the genus Araeoncus View in CoL .

Araeoncus hyalinus View in CoL n. sp. and A. longispineus View in CoL n. sp. share a number of characteristics, including similar body size, body coloration and genital structures, but differ in details. Males can be distinguished by 1) the shape of cephalic lobe, which is much smaller in A. hyalinus View in CoL n. sp. ( Fig. 2B View FIG ) than in A. longispineus View in CoL n. sp. ( Fig. 5A View FIG ); 2) the presence of 3 trichobothria on the palpal tibia in A. hyalinus View in CoL n. sp. ( Fig. 1A View FIG ) versus 2 in A. longispineus View in CoL n. sp. ( Fig. 4D View FIG ); 3) the shape of the palpal prolateral tibial apophysis, which is composed of a S-shaped and a rhombic sclerite in A. hyalinus View in CoL n. sp. ( Fig. 1E View FIG ), but only a long pointed apophysis with membranous base in A. longispineus View in CoL n. sp. ( Fig. 4D View FIG ); 4) the presence of a long thick spine on the cymbial retrobasal process of the palp in A. longispineus View in CoL n. sp. ( Fig. 4C View FIG ), absent in A. hyalinus View in CoL n. sp. ( Fig. 1D View FIG ); 5) the presence of a rectangular extension at the base of the distal suprategular apophysis in A. hyalinus View in CoL n. sp. ( Fig. 1C View FIG ), absent in A. longispineus View in CoL n. sp. ( Fig. 5A View FIG ); 6) the shape of embolus, slightly sclerotized and with almost even dimensions in A. hyalinus View in CoL n. sp. ( Fig. 2D View FIG ), versus highly sclerotized and strongly widened distally in A. longispineus View in CoL n. sp. ( Fig. 5D View FIG ); 7) the relatively short anterior radical process in A. hyalinus View in CoL n. sp. ( Fig. 1B View FIG ), but long and with an extra tooth behind in A. longispineus View in CoL n. sp. ( Fig. 4B View FIG ); and 8) the shape of posterior radical process, which is narrow and almost even in A. hyalinus View in CoL n. sp. ( Fig. 2D View FIG ), wide at the base and strongly narrowed in A. longispineus View in CoL n. sp. ( Fig.5D View FIG ) and the shape of tailpiece of radix, hunched in the middle, blunt distally and slightly upwards in prolateral view in A. hyalinus View in CoL n. sp. ( Fig. 1C View FIG ), but different in A. longispineus View in CoL n. sp. ( Fig. 4A View FIG ).

Females can be further distinguished by the size of the dorsal plate, which is wider than the length of the long arm of the spermatheca in A.hyalinus n. sp. ( Fig. 3A View FIG ), but narrower in A. longispineus n. sp. ( Fig. 5F View FIG );by the shape of slightly sclerotized capsule where copulatory ducts are embedded, much wider in A. hyalinus n. sp. ( Fig. 3D, E View FIG ) than in A. longispineus n. sp. ( Fig. 5F, H View FIG ) and by the length of the short arm of the U-shaped spermatheca, which is half the long arm of the spermatheca in A. hyalinus n. sp. ( Fig.3E View FIG ), but more than half in A. longispineus n. sp. ( Fig. 5H View FIG ).

Furthermore, both new species can be easily diagnosed from other Araeoncus species by the shape of palpal tibial apophyses ( Figs 1E View FIG ; 4D View FIG ), which are not typical biforked shape as in A. humilis (see Wiehle 1960: fig. 431), by the presence of posterior radical process and mesal tooth of embolic division ( Figs 2E View FIG ; 5D View FIG ) and by the postero-median triangular prolongations of the bisected epigynum ( Figs 3B View FIG ; 5G View FIG ).

Specimens of A. hyalinus n. sp. were found under leaf litter or among the roots of moss in mountains above 3000 m. 4 ♂♂ and 40 ♀♀ were measured. Total length varies from 1.53-1.56 in males, 1.36- 1.77 in females. Carapace length is 0.78-0.81 in males, 0.64-0.69 in females; width 0.60-0.62 in males, 0.48-0.56 in females. Coloration of carapace varies from dull-yellow to nut-brown, abdomen light grey to dark grey.