Theridiosoma triumphale Zhao & Li 2012
Creators: name: Ballarin, Francesco
name: Yamasaki, Takeshi
name: Su, Yong-Chao
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Theridiosomatidae
Theridiosoma
Theridiosoma triumphale

description: Theridiosoma triumphale Zhao & Li, 2012
Figs. 3A ̅D, 4 A–E.
T. triumphalis Zhao & Li, 2012: 37, f. 24 A̅D, 25 A, B (³). (Holotype Ƌ from CHINA: Hainan Island, Mt. Jianfengling National Nature Reserve, Tianchi watershed, 19 JULY 2007, leg. Li S. (IZCAS); examined, based on photos).
Material examined TAIWAN: 1♀, Taitung County, Orchid Island (Lanyu), Hongtou neighborhood, along the trail to Datianchi lake († R ¨), Elev. 106m a.s.l., (22°00’46.2”N, 121°34’13.9”E), 13. JUNE.2019, rainforest litter (NMNS); 1³, 1♀, Dongqing neighborhood, rainforest litter, Elev. 50 m a.s.l., (22°01’42.5”N, 121°34’36.4”E), 14. JUNE.2019, (NMNS); 1♀, same locality, 40 m a.s.l., (22.029878N, 121.575075), 15. JUNE.2019, all leg. Ballarin F. (FBPC).
Diagnosis. For male diagnosis see Zhao & Li 2012, p. 39. Female of this species can be easily distinguished from female of Asian congeners by the presence of a short but well-developed scapus on the epigynal plate. In addition, female T. triumphale can be distinguished from female T. diwang Miller, Griswold & Yin, 2009 and T. shuangbi Miller, Griswold & Yin, 2009 by the position of the spermathecae, located high over the copulatory ducts in contrast with spermathecae located adjacent to the copulatory ducts in the latter two species (see Fig. 4B, C vs. figs. 3G, I in Miller et al. 2009).
Description. Male. Measurements: total length: 1.24; carapace: 0.63 long, 0.58 wide.
Habitus as in Fig. 4D. Palp as in Fig. 3 A–D. Opisthosoma uniformly yellowish, bearing 3̅4 silver patches on the dorsal side, most of them aligned in a transversal stripe around the central part of opisthosoma. For the main description of body and palp see Zhao & Li, 2012, p. 39, 40.
Female. Habitus as in Fig. 4E. Measurements: total length: 1.60; carapace: 0.62 long, 0.56 wide. Carapace uniformly yellowish. Cephalic area distinctly elevated. Chelicera, labium and sternum uniformly yellowish, slightly darker than in the male. Legs yellowish, covered with numerous spines. Tibia, metatarsus and tarsus slightly darker. Leg measurements: I: (1.89) 0.61, 0.24, 0.41, 0.39, 0.24; II: (1.66) 0.53, 0.21, 0.35, 0.34, 0.23; III: (1.06) 0.32, 0.15, 0.18, 0.23, 0.18; IV: (1.43) 0.48, 0.20, 0.28, 0.28, 0.19. Opisthosoma uniformly yellowish, bearing a transverse stripe of silver patches in the middle of the dorsal side, more extended and obvious than in the male. Spinnerets uniformly yellowish.
Epigyne and vulva as in Fig. 4 A–C. Epigynal plate flat with a short, squared scape protruding from the posterior margin and a pair of lateral pits. Inner epigynal plate with several small marks. Copulatory ducts large, visible through the translucent ventral cuticle. Copulatory ducts connect to the posterior side of the spermathecae. Fertilization ducts narrow, S-shaped. Spermathecae small and subspherical, close to each other and located in the anterior section of the epigyne, over the copulatory ducts.
Distribution. Known only from two localities: Hainan Island (type locality) and Orchid Island (Fig. 7). This is the first record of this species for Taiwan.
Habitat. Humid rainforest leaf litter.
Remarks. Theridiosoma triumphale was described for the first time by Zhao & Li (2012) based on a single male specimen from Hainan Island, China. Due to the poor condition of the sample, no description of the opisthosoma could be included (Zhao & Li 2012 p. 39). The female was previously unknown. We had the opportunity to examine high quality photos of the palp of the holotype and failed to identify significant morphological discrepancies with the specimens from Orchid Island. Minor differences can be attributed to intraspecific variation. Based on this assumption we consider the specimens from Orchid Island as belonging to the same species. Thus, we describe the female for the first time, and illustrate the habitus of both sexes. The new records extend the distribution of T. triumphale approximately 1200 km to the east. Despite extensive collections, only few specimens were found and only in the southern part of the island (Fig. 7). Theridiosoma triumphale may be widespread, but locally rare.
description: Published as part of Ballarin, Francesco, Yamasaki, Takeshi & Su, Yong-Chao, 2021, A survey on poorly known rainforest litter-dwelling spiders of Orchid Island (Lanyu, Taiwan) with the description of a new species (Araneae: Linyphiidae Tetrablemmidae, and Theridiosomatidae), pp. 197-208 in Zootaxa 4927 (2) on page 201, DOI: 10.11646/zootaxa.4927.2.2, http://zenodo.org/record/4536966