Prosoponoides hamatum Millidge & Russell-Smith 1992
Creators: name: Chen, Qianjun
name: Zhong, Yang
name: Liu, Jie
name: Chen, Jian
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Prosoponoides
Prosoponoides hamatum

description: Prosoponoides hamatum Millidge & Russell-Smith, 1992
Figs 1–3, 9
Material examined: 4 males and 6 females, China, Hainan Provinc e: Qiongzhong County, Li Mu Mountain National Nature Reserve, 19.21°N, 109.78°E, 345m, 2 October 2009, H. Yu leg. (CBEE).
Diagnosis: The male of P. hamatum can be distinguished from other Prosoponoides species by the shape of tegulum which is not humping medially but significantly humping medially in other Prosoponoides species (Figs 1B, 2B, 4B, 6C, 7B); by the highly sclerotized embolic base (Figs 1E, 2 D–E) which is absent in P. sinense (Fig. 4D) and Prosoponoides youyiensis n. sp. (Figs 6E, 7 D–E). The female of P. hamatum can be distinguished from P. kaharianus by the small depression of parmula (Figs 1C, 1 F–G, 3C–E), about 1/3 parumla wide in P. hamatum which is large, about 1/2 parmula wide in P. kaharianus; from Prosoponoides sinense by the following characters: 1, the parmula is tongue-shaped in P. hamatum, but semicular in P. sinense (Figs 5 C–E); 2, the copulatory ducts (Figs 1 F–E, 3D–E) about one and half coils in P. hamatum, but two and half in P. sinense (Figs 5 D–E); from P. youyiensis n. sp. by the spermathecae which is located laterally in P. hamatum (Figs 1G, 3E), but medially in P. youyiensis n. sp. (Figs 6G, 8D).
Description: Male: Total length: 3.3. Carapace: 1.25 long, 1 wide. Abdomen: 1.7 long, 1 wide. Carapace gray-brown, unmodified. Eyes equal. AER recurved, AME-AME shorter than AMEd, AME-ALE about AMEd; PER straight, PME-PME slightly shorter than PMEd, PME-PLE longer than PMEd; ALE and PLE juxtaposed. Chelicerae yellow-brown, stridulatory ridges weak, promargin of fang furrow three teeth, first smaller than the others, retromargin 2 equal teeth. Lengths of legs: I 6.1 (1.88+1.73+1.6+0.89), II 5.23 (1.5+1.6+1.4+0.73), III 3.03 (0.83+0.9+0.8+0.5), IV 4.8 (1.33+1.36+1.33+0.78). Abdomen cylindrical, gray with whitish spots laterally and dorsally (Fig. 3B).
Male palp (Figs 1 A–B, 1D–E, 2): Patella short, with long spine dorsally. Tibia shorter than cymbium, with several long spines on lateral and ventral surfaces. Paracymbium tiny, curved upwardly. Suprategular stout, curved medially at a right angle. Lamella well-developed, with four projections: lateral one broad, sheet-shaped, with a sharp end curved upwardly, and posterior one short and broad; anterior one small; dorsal one short. Second membrane small. Embolus filiform.
Female: Total length: 2.45. Carapace: 1.2 long, 1.1 wide. Abdomen: 2.05 long, 1.5 wide. Carapace yellowbrown, unmodified. Eyes equal. AER recurved, AME-AME shorter than AMEd, AME-ALE about AMEd; PER straight, PME-PME slightly shorter than PMEd, PME-PLE longer than PMEd; ALE and PLE juxtaposed. Chelicerae yellow-brown, stridulatory ridges absent, promargin of fang furrow three teeth, first smaller than others, retromargin 2 equal teeth,. Lengths of legs: I 4.79 (1.33+1.56+1.23+0.67), II 4.34 (1.23+1.47+1.07+0.57), III 2.83 (0.8+0.9+0.73+0.4), IV 3.7 (1.06+1.08+0.93+0.63). Other somatic characters same as male (Fig. 3A).
Epigynum (Figs 1C, 3C): Atrium oval, divided into two openings by septum. Parmula tongue-shaped, arising from dorsal wall but connecting with septum, with a small depression at its tip. Vulva (Figs 1 F–G, 3D–E): Vulva as long as wide; copulatory ducts started from the two atrium openings, with about one and half coils; fertilization duct without coils, directly running downwards from the spermatheca inside the spiral tracing of copulatory duct; spermathecae slender, significantly curved, pointing towards mesally.
Remarks: Although we did not examine the holotype of P. hamatum, Dr. Qingyuan Zhao helped us to check the photos and made sure that it was same species as what he collected in Xishuangbanna, Yunnan Province and identified as P. hamatum (Zhao & Li, 2014). The same embolic division (filiform embolus with strongly sclerotized base, lateral projection of lamella with a sharp end curved upwardly) indicates the male should belong to P. hamatum. However, the female shows a little difference in the tongue-shaped parmula (semiellipse-shaped reported by Millidge & Russell-Smith 1992) and the internal structure. We think that the differences in the parmula shape are caused by differences in observation angle, they may be same if our epigynum is placed downward anteriorly. Also, the vulva reported by Millidge & Russell-Smith (1992: 1374) was not cleared in boiling KOH solution to dissolve non-chitinous tissues which we did, because the authors mention “the heavy sclerotization, and the fusion of the various parts, make it difficult to be completely certain of the duct pathways”. In addition, the round copulatory openings and the curved and slender spermathecae indicate that the female belongs to P. hamatum.
Distribution: China (Hainan, new record; Yunnan), Indonesia (Sumatra) (Fig. 9).
description: Published as part of Chen, Qianjun, Zhong, Yang, Liu, Jie & Chen, Jian, 2020, The spider genus Prosoponoides (Araneae: Linyphiidae) in China, pp. 23-36 in Zootaxa 4786 (1) on pages 24-28, DOI: 10.11646/zootaxa.4786.1.2, http://zenodo.org/record/3864962