Research Article |
Corresponding author: Chao Zhang ( opiliones@163.com ) Academic editor: Adriano Kury
© 2018 Chao Zhang, Jochen Martens.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Zhang C, Martens J (2018) Ancient home or in exile? The easternmost species of genus Starengovia Snegovaya, 2010 found in China (Opiliones, Nemastomatidae, Nemastomatinae). ZooKeys 770: 105-115. https://doi.org/10.3897/zookeys.770.25491
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Starengovia quadrituberculata sp. n. is described and illustrated based on male and female specimens collected in Yunnan Province, China. The new species is distinct from the two other congeners, S. kirgizica Snegovaya, 2010 and S. ivanloebli Martens, 2017, in having two pairs of low submedian tubercles on abdominal areae III and IV; distal margin of the lateral foliate wing-like structures of the penis situated close to the glans base, the short rod-like stylus, the form and position of spines on the stylus of the penis, anvil-shaped tubercles mainly on front margin of prosoma. The occurrence of Starengovia in Yunnan, the second nemastomatine species in China, creates a huge distributional gap of roughly 2700 km distance to its closest neighbor S. ivanloebli in Northwest Pakistan. The historical relations of Chinese nemastomatines are discussed.
East Palaearctic, genitalia, harvestmen, relict species, Starengovia , taxonomy, Yunnan Province
The family Nemastomatidae Simon, 1872 is currently represented by two subfamilies (Ortholasmatinae Shear & Gruber, 1983, and Nemastomatinae Simon, 1872) and includes 23 genera and 138 species worldwide (
Taxonomic scheme follow the outline proposed by
Starengovia
Snegovaya, 2010: 351–352;
Starengovia kirgizica Snegovaya, 2010, original designation.
Small species up to 1.7 mm, dorsal scutum with lines of anvil-shaped tubercles along margins of scutal areas. Pairs of para-median tubercles on opisthosomal areas of dorsal scutum. Truncus penis moderately slender, large muscle-containing inflated base, truncus in straight continuation of inflated base. Distal part of truncus with one large lateral wing on either side, glans inconspicuous, not well differentiated from truncus; armament of glans simple with symmetrical arrangement. Apophysis on basal cheliceral article of male well-marked, with a distad-directed hook, discharge area for secretion in a bowl-like excavation on medial side of apophysis (
China (Yunnan), Kyrgyzstan, Uzbekistan, Himalayas of Pakistan.
1 | Distributed in Yunnan, China, low para-median tubercles on opisthosomal areae III and IV (Figs |
S. quadrituberculata sp. n. |
– | Distributed in Central Asia (Kyrgyzstan, Uzbekistan) and NW Pakistan; high slender or compact para-median tubercles on opisthosomal areae I–V; penis with alae of wings bent to ventral side or straight, not bent | 2 |
2 | Distributed in Kyrgyzstan (one record also in Uzbekistan), tubercles of dorsal scutum conical and compact; penis with alae of wings bent to ventral side | S. kirgizica |
– | Distributed in northwestern Pakistan, tubercles of dorsal scutum slender, penis with alae of wings straight, not bent to ventral side | S. ivanloebli |
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.
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.
1♀ (MHBU-Opi-20171209), same data as the holotype.
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.
Habitus as in Figs
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).
Dorsum (Figs
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).
Venter (Fig.
Chelicerae (Figs
Pedipalpi (Figs
Legs (Figs
Penis (Figs
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.
Female (Figs
Ovipositor (Figs
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
Starengovia quadrituberculata sp. n. Measurements of the pedipalp and legs of the male holotype, as length/depth.
Trochanter | Femur | Patella | Tibia | Metatarsus | Tarsus | Total | |
---|---|---|---|---|---|---|---|
Pedipalp | 0.21/0.11 | 0.63/0.06 | 0.48/0.07 | 0.41/0.08 | 0.27/0.07 | 2.00 | |
Leg I | 0.22/0.14 | 0.91/0.16 | 0.37/0.17 | 0.59/0.17 | 1.15/0.06 | 1.01/0.05 | 4.25 |
Leg II | 0.22/0.14 | 1.85/0.09 | 0.50/0.13 | 1.28/0.10 | 3.29/0.06 | 2.17/0.05 | 9.31 |
Leg III | 0.22/0.14 | 1.01/0.16 | 0.34/0.18 | 0.56/0.14 | 1.13/0.06 | 0.96/0.05 | 4.22 |
Leg IV | 0.22/0.14 | 1.40/0.14 | 0.36/0.17 | 0.79/0.15 | 1.65/0.06 | 1.20/0.05 | 5.62 |
Starengovia quadrituberculata sp. n. Measurements of the pedipalp and legs of the female paratype, as length/depth.
Trochanter | Femur | Patella | Tibia | Metatarsus | Tarsus | Total | |
---|---|---|---|---|---|---|---|
Pedipalp | 0.23/0.11 | 0.66/0.06 | 0.53/0.07 | 0.42/0.06 | 0.29/0.07 | 2.13 | |
Leg I | 0.22/0.14 | 0.89/0.15 | 0.37/0.16 | 0.59/0.15 | 1.13/0.06 | 1.02/0.05 | 4.22 |
Leg II | 0.22/0.14 | 1.82/0.09 | 0.53/0.13 | 1.22/0.10 | 3.26/0.06 | 2.13/0.05 | 9.18 |
Leg III | 0.22/0.14 | 0.91/0.14 | 0.35/0.17 | 0.53/0.14 | 1.15/0.06 | 0.91/0.05 | 4.07 |
Leg IV | 0.22/0.14 | 1.36/0.13 | 0.37/0.17 | 0.70/0.12 | 1.60/0.06 | 1.19/0.05 | 5.44 |
The specimens were collected by leaf litter sieving in broad-leaved forest under dense canopy at an altitude of 2142 m ASL.
Known only from the type locality in southern Yunnan Province, China.
The discovery of a species of the genus Starengovia in Yunnan comes quite unexpectedly. Starengovia is known from Central Asian Kyrgizstan and Uzbekistan only by a few localized records of S. kirgizica Snegovaya, 2010. Starengovia ivanloebli Martens, 2017 is known from the Himalayas of Northwest Pakistan, disjunct by 700 km. The present record of S. quadrituberculata sp. n. moves the distributional limit of nemastomatines by a second species by roughly 2700 km to the Southeast to southern Yunnan Province in China. The first nemastomatine ever discovered in China is Sinostoma yunnanicum Martens, 2016, only 380 km to the northeast of the present record, in Yunnan as well. Both are minute species less than 2 mm in body length, difficult to discover and apparently restricted to primeval mountain forests above 2000 m.
The few records of nemastomatines in East Asia hitherto known are restricted to two genera and appear to be remarkably disjunct from the European nemastomatine core distributional area. Though more local Asian occurrences may be discovered in the future, these are rare harvestmen and probably relicts of old lineages which do not exist in the West Palaearctic and probably never occurred there. According to only punctual, disjunct distributional areas and morphological traits Central Asian and Chinese occurrences of nemastomatines seem to represent “ancient homes” rather than “recent exiles”, i.e., geographical outliers of the main prosperous and speciose West Palaearctic radiations. This is meant in a dynamic sense – not just static as marginal occurrences.
In accordance with this hypothesis, Starengovia and Sinostoma display rather plesiomorphic genitalic characters (
For access to rare specimens we are deeply indebted to Yannan Mu, Zhaoyi Li and Zegang Feng. This work was supported by a grant of the National Natural Science Foundation of China (No. 31471956) to CZ. JM got grants from Feldbausch Foundation and Wagner Foundation at Fachbereich Biologie of Mainz University to carry out field work in Asia. CZ acknowledges financial support from the researcher alumni network senckenberg, Frankfurt am Main, Germany (FANS). Jürgen Gruber and Christopher Taylor critically commented on an earlier version of the manuscript and gave valuable input. We heartily thank all friends, colleagues, and institutions.