Starengovia quadrituberculata, Zhang & Martens, 2018

Zhang, Chao & Martens, Jochen, 2018, Ancient home or in exile? The easternmost species of genus Starengovia Snegovaya, 2010 found in China (Opiliones, Nemastomatidae, Nemastomatinae), ZooKeys 770, pp. 105-115 : 105

Starengovia quadrituberculata sp. n. Figs 1-7 , 8-19 , 20-25 , 26-31

Diagnosis.

Areae III-IV of opisthosomal region each with a pair of very low median tubercles inclined posteriorly. Basal segment of chelicerae dorso-distally with a triangular apophysis in male (in lateral view). Distal part of penis with extended lateral wing structure; width of the wings almost equivalent to length. Glans short, nearly cone-shaped; stylus short and conical. Scanty anvil-shaped tubercles confined to front margin of prosoma.

Type locality.

CHINA, Yunnan Province: Baoshan City, Lujiang Town, Dahaoping, 24°57'42"N, 98°43'58"E, 2142 m ASL, evergreen forest, sifted from leaf litter.

Type specimen. Holotype male (MHBU-Opi-20171208). Adult male preserved in 75% ethanol, with genitalia in a separate microvial. Original label: MHBU-Opi-20171208, CHINA: Yunnan Province, Baoshan City, Lujiang Town, Dahaoping, 24°57'42"N, 98°43'58"E, 2142 m ASL, 23 November 2017, Y.N. Mu leg.

Paratype.

1♀ (MHBU-Opi-20171209), same data as the holotype.

Etymology.

The specific name is taken from the Latin quadri - (four) and tuberculum (tubercle, small apophysis), referring to the two pairs of small tubercles on opisthosomal areae III and IV.

Description of the male holotype.

Habitus as in Figs 1 , 8 , 26-28 . Coloration in alcohol: dorsum brown black, without silvery or golden markings (Fig. 26 ). Venter concolorous with the dorsum (Fig. 28 ), but intersegmental membranes whitish. Chelicerae and pedipalpi chestnut-brown. Legs deep black.

Dorsum (Figs 8 , 26 ). Body small, strongly sclerotized. Dorsal scutum ovoid in shape. Anterior margin of the carapace nearly rounded, armed with a continuous row of anvil-shaped tubercles, posterior margin slightly rounded, more quadrangular. Ocularium slightly elevated, rising from frontal margin of scutum, irregularly covered with quadrangular tubercles. Supracheliceral lamellae consisting of three small sclerite plates. Metapeltidial area and opisthosomal region (areae I-V) separated by lines of quadrangular tubercles similar to those at peripheral margins of the scutum. Areae III-IV each with a pair of low median pegs inclined posteriorly. Free tergites not visible from above.

Venter (Fig. 28 ). Coxae with scattered low rounded tubercles on ventral surfaces and pro-laterally and retro-laterally with a row of quadrangular tubercles. Genital operculum short, almost tongue-shaped, surface with scattered tubercles. Free sternites with few tubercles at margins.

Chelicerae (Figs 2-5 ). Basal segment ventrally and medially each with a rounded hump at the base (medial view, Fig. 2 ), and dorso-distally with a triangular apophysis distinctly surpassing front margin of basal segment, approximately as long as high (in lateral view), medially compressed and spoon-shaped (medial view, Fig. 2 ); apophysis medially inclined dorso-distally projecting into a pointed hook, dorsally with two long setae; the medial excavation of apophysis harbouring the secretion porefield; a few tubercles laterally and dorsally on medial part of basal segment (Figs 3-4 ); a multitude of minute granules on the ventro-lateral surface of basal segment (Fig. 3 ). The second segment with a few tubercles laterally and dorsally at base. Many long dorsal setae and rows of short setae at base of fixed finger (Fig. 2 ). Fingers short, with diaphanous teeth and dark subapical teeth: one dark tooth on movable finger, two dark teeth on fixed finger (Fig. 5 ).

Pedipalpi (Figs 6-7 ). Trochanters with three ventral seta-tipped tubercles. Femora and patellae with normal straight setae mainly on dorsal and lateral sides. Femora slightly swollen distally and ventrally with sparse clavate setae. Patellae ventrally slightly thickened and medially, ventrally and laterally with sparse clavate setae. Tibiae and tarsi densely covered with clavate setae all round.

Legs (Figs 9-12 ). Femora, patellae, and tibiae of leg I, III and IV slightly inflated. Femora, patellae, and tibiae of all legs densely covered with stiff, short bristles (Fig. 9 ). Pseudoarticulations of femora I-IV: 2/7/2/3; pseudoarticulations of metatarsi I-IV: 0/13/1/3. Tarsal segments I-II with two tarsomere groups: 8 (6+2), 24 (22+2); III-IV with three each: 9 (5+2+2), 9 (5+2+2).

Penis (Figs 20-25 ). Moderately slender; no clear distinction between truncus, glans, and stylus. Basis forming a large inflated part (occupying approximately one third of whole penis length) and deeply split into two parts each bearing one large muscle portions, basis well differentiated from rest of truncus; truncus beyond basis parallel-sided, distal portion close to glans inconspicuously curved (lateral view). Ventro-lateral side of truncus sub-distally with two broad foliate wing-like structures forming a transparent membrane, triangular, free pointed end curled to ventral side. Glans extremely short, armament of glans with pairs of short spicule-like setae; three pairs on dorsal side, two pairs more distally on both “lateral” sides, stylus short and rod-like.

Female (Figs 13-15 , 29-31 ). In appearance and coloration similar to the male, but body much larger (Figs 13 , 29 ). Free tergites visible from above (Fig. 13 ). Basal segment of chelicerae dorso-distally with a hump covered with two long setae, and ventrally with a multitude of minute granules, similar granules medially at the base (Fig. 14 ). Patellae of pedipalpi with many clavate hairs (Fig. 15 ). Pseudoarticulations of femora I-IV: 2/7/2/3-4; pseudoarticulations of metatarsi I-IV: 1/14/2/3. Tarsal segments I-IV: 9 (7+2), 15 (13+2), 8 (4+2+2), 10 (6+2+2).

Ovipositor (Figs 16-19 ). Short type ( Martens et al. 1981, Suzuki 1974: 88), unsegmented. The apical furca bipartite, each bearing 16 setae in three groups: six long setae at the base of furca (Fig. 18 ), four short ones medially at the margin of apical lobe (Fig. 19 ), and six long ones between former two groups (Fig. 19 ).

Measurements.

Male holotype (female paratype): Body 1.41 (1.75) long. 0.96 (1.26) wide at the widest portion. Ocularium 0.13 (0.18) long, 0.23 (0.23) wide. Basal segment of chelicerae 0.32 (0.30) long; second segment of chelicerae 0.45 (0.54) long. Penis 0.75 long (including glans), 0.05 wide at base, alate part 0.20 wide, fork 0.39 long. Ovipositor 0.60 long. Measurements of left pedipalp and right legs as in Tables 1 , 2 .

Habitat.

The specimens were collected by leaf litter sieving in broad-leaved forest under dense canopy at an altitude of 2142 m ASL.

Distribution.

Known only from the type locality in southern Yunnan Province, China.

Figures

Figures 1 - 7. Starengovia quadrituberculata sp. n. male (holotype) 1 Body, lateral view 2 Left chelicera, medial view 3 Left chelicera, ectal view 4 Basal segment of left chelicera, dorsal view 5 Left cheliceral fingers, frontal view 6 Left pedipalp, medial view 7 Left pedipalp, ectal view. Scale bars 0.5 mm (1); 0.25 mm (2 - 7).

Figures 8 - 19. Starengovia quadrituberculata sp. n. 8 Body, male, dorsal view 9 - 12 Right legs, retrolateral view 9 Leg I 10 Leg II 11 Leg III 12 Leg IV 13 Body, female, dorsal view 14 Left chelicera, female, medial view 15 Left pedipalp, female, medial view 16 Ovipositor, ventral view 17 Ovipositor, dorsal view 18 Ovipositor, lateral view 19 Ovipositor, frontal view. Scale bars 1 mm (9 - 13); 0.5 mm (8); 0.25 mm (14 - 18).

Figures 20 - 25. Starengovia quadrituberculata sp. n. male (holotype) 20 Penis, dorsal view 21 Penis, ventral view 22 Penis, lateral view 23 Penis tip, dorsal view 24 Penis tip, ventral view 25 Penis tip, lateral view. Scale bars 0.25 mm (20 - 22); 0.05 mm (23 - 25).

Figures 26 - 31. Starengovia quadrituberculata sp. n. Photographs of holotype male and female paratype 26 Body and parts of appendages, male, dorsal view 27 Ditto, lateral view 28 Ditto, ventral view 29 Body and parts of appendages, female, dorsal view 30 Ditto, lateral view 31 Ditto, ventral view. Scale bars 0.5 mm.