Araneae: Theridiosomatidae) with the Description of Four New Species

Acta Arachnologica, 69 (2): 133–150, December 20, 2020

Japanese spiders of the genus Theridiosoma (Araneae: Theridiosomatidae) with the description of four new species

Yuya Suzuki1*, Ryohei Serita2 & Takehisa Hiramatsu3

1Graduate School of Life and Environmental Science, University of Tsukuba, 1-1-1, Tennodai, Tsukuba-shi, Ibaraki, 305-8572 Japan 2Science and Technology Program, Graduate School of Integrated Arts and Science, Kochi University, 2-5-1, Akebono-cho, Kochi-shi, Kochi, 780-8520 Japan 3Fregrance-Uwado, 203, Uwado, Kawagoe-shi, Saitama, 350-0816, Japan *Corresponding author E-mail: [email protected]

Abstract ― Japanese spiders of the genus Theridiosoma (Araneae: Theridiosomatidae) were revised with redescription of T. epeiroides Bösenberg & Strand 1906 and description of four new species, namely: T. dissimulatum sp. nov., T. paludicolum sp. nov., T. fulvum sp. nov., and T. alboannulatum sp. nov. The internal morphology of the female genitalia of T. epeiroides is illustrated in this study for the first time. Males of the new species can be distinguished from their congeners by the morphology of the embolic apophyses or the posterior edge of the embolic division on the male palp. Females of the former three species can be differentiated from their related species by the shape of the contour formed by interior edges of a pair of sclerotized processes on the posterior edge of the genital plate. The latter species can be distinguished from the allied species by the angular lateral corners of the genital plate and overall shape of the genitalia (longer than wide).

Key words ― Conductor projection, embolic apophysis, epigyne, morphology, new species, process, taxonomy

never been illustrated in T. epeiroides. Introduction Based on the species diversity of neighboring countries, The family Theridiosomatidae Simon 1881 is composed we expected the potential diversity of Theridiosoma spi- of tiny species (0.5–3 mm in body length and often less than ders in Japan and conducted field surveys in various envi- 2 mm in total length) and is known to build deformed orb ronments including side of streams in forests, riverbeds, webs (Coddington 1986; Ono & Shinkai 2009). Theridioso- wetlands, shores of lakes, and ponds from Hokkaido to the ma O. Pickard-Cambridge 1879 is one of the theridiosoma- Southwest Islands. From the survey, we obtained several tid spider genera that weaves a cone-shaped orb web (Cod- specimens of the genus that could not be identified as de- dington 1986). To date, 33 species of the genus have been scribed species. In this study, we redescribed T. epeiroides recorded from East Asia to Southeast Asia, America, and with the first description of its vulva and examined the Africa (World Spider Catalog 2020) and six species of them morphology of unidentified specimens. The study revealed have been described in China and Taiwan in recent years that four species are new to science and are described in this (Zhang et al. 2006; Miller et al. 2009; Zhao & Li 2012). paper. In the Japanese spider fauna, only two species, T. gemmo- Materials and Methods sum (L. Koch 1877) and T. epeiroides Bösenberg & Strand 1906, have been recorded (Tanikawa 2020). T. gemmosum All specimens are preserved in 80% (v/v) ethanol, their was only recorded from the Chishima Islands in 1959 with morphological features were observed under a stereoscopic a very rough description of its specimens, and there have microscope (Nikon AZ100M, Japan) and photographs tak- been no additional records described since then (Saito 1959; en by the device were stacked using microscope imaging Ono & Shinkai 2009). T. epeiroides is a common species in software (Nikon NIS-Elements D 4.20.00 64-bit, Japan). All Japan, and its morphology has been well described (Bösen- materials used in this study are deposited in the collection of berg & Strand 1906; Marusik 1989; Ono & Shinkai 2009); the Zoological Department of Nature and Science Museum, however, the vulva, which is often regarded as an important Tsukuba (NSMT). taxonomic key for small spiders and has recently been well The following abbreviations have been used in this paper: described in theridiosomatids (e.g. Miller et al. 2009), has ALE: anterior lateral eye; AME: anterior median eye; C: 134 Y. Suzuki, R. Serita & T. Hiramatsu

Fig. 1. A–B, habitus of Theridiosoma epeiroides, male (specimen from Ibaraki Pref.); C–D, same, female (specimen from Ibaraki Pref.); E–F, T. dissimulatum sp. nov., male (holotype); G–H, same, female (paratype from Amami-ohshima Is.); A, C, E, G, dorsal view; B, D, F, H, lateral view. Scales=0.5mm.

conductor; CD: copulatory duct; CP: conductor projection; several long bristle-like parts (Coddington 1986). Note that E: embolus; EA: embolic apophysis; ED: embolic division; the poorly defined genus Zoma Saaristo 1996, which was FD: fertilization duct; MA: median apophysis; PLE: posteri- not examined by Coddington (1986), relatively resembles or lateral eye; PME: posterior median eye; S: spermatheca; Theridiosoma. Although females can be distinguished by ST: subtegulum; T: tegulum. The measurements of the legs the presence of a median and two lateral pits on a flat genital are given in the following format: [tarsus + metatarsus + plate, a male of the type species Z. zoma Saaristo 1996 is tibia + patella + femur = total]. All measurements are given not described. Therefore, the characteristics that differentiate in mm. The names of each part of the male palp and female males of Zoma from those of Theridiosoma are not clear. genitalia are based on the descriptions by Coddington (1986), Dupérré & Tapia (2017), and Miller et al. (2009). Theridiosoma gemmosum (L. Koch 1877) [Japanese name: Kuro-karakara-gumo] Taxonomy Genus Theridiosoma O. Pickard-Cambridge 1879 Theridiosoma gemmosum L. Koch 1877, p181, figs. 6–8 (Type series [Japanese name: Karakara-gumo-zoku] from Nuremberg, West Germany, not examined in this study). See the World Spider Catalog (2020) for the complete taxonomic list.

Theridiosoma O. Pickard-Cambridge 1879, p193 [Type species T. ar- Diagnosis. According to Coddington (1986), females and genteolum O. Pickard-Cambridge 1879 (= T. gemmosum (L. Koch 1877)) from England, not examined in this study]. males of the species can be distinguished from related spe- See the World Spider Catalog (2020) for the complete taxonomic list. cies by strongly sclerotized and hood-shaped epigyne and Remarks. Species of the genus can be distinguished palps lacking conductor projection (named as “distal apoph- from other theridiosomatid genera by the morphology of ysis” in the reference). the embolic division on the male palp, which is a short and Notes. In Japan, T. gemmosum was only recorded from tubular embolus with embolic apophyses fragmented into the Chishima Islands in 1959, with a very rough description

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Fig. 2. A–B, habitus of Theridiosoma paludicolum sp. nov., male (holotype); C–D, same, female (paratype from Ibaraki Pref.); E–F, T. fulvum sp. nov., male (holotype); G–H, same, female (paratype from Saitama Pref.); I–J, T. alboannulatum sp. nov., male (holotype); K–L, same, female (paratype from Iriomote-jima Is.). Scales=0.5mm.

of its specimens (Saito 1959). As the specimens were not See the World Spider Catalog (2020) for the complete taxonomic list. deposited to public institutions and possibly lost, it is impos- sible to reexamine them. Moreover, there have not been ad- Specimens examined. All specimens were collected ditional records reported since then (Ono & Shinkai 2009). in Japan. YAMAGATA PREF.: 1♀, Masuda, Sakata-shi, Thus, we regard the occurrence of T. gemmosum in Japan as 27-VIII-2019, R. Serita leg.; IBARAKI PREF.: 11♂10♀, an uncertain record. Ono & Shinkai (2009) mentioned that T. Tennodai, Tsukuba-shi, 29-V-2019 (6♂6♀), 11-VI-2019 gemmosum might be found in mountainous regions at high (3♂4♀), 3-VI-2020 (2♂), Y. Suzuki leg.; 2♂2♀, Oda, altitudes, based on the palearctic distribution of the species. Tsukuba-shi, 24-III-2017 (1♂), 27-V-2017 (1♀), 27-IX- 2017 (1♂1♀), Y. Suzuki leg.; 1♂6♀, Kamifuruuchi, Shi- Theridiosoma epeiroides Bösenberg & Strand 1906 rosato-machi, Higashi-ibaraki-gun, 5-VII-2020, Y. Suzuki [Japanese name: Karakara-gumo] leg.; TOKYO: 17♂36♀, Nippara, Okutama-machi, Nishita- (Figs. 1A–D, 3A–C, 5A–B, 7A–L, 13A–D) ma-gun, 28-VI-2020, Y. Suzuki leg.; YAMANASHI PREF.: 3♀, Doshi-mura, Minamitsuru-gun, 24-VII-2019, Y. Suzuki Theridiosoma epeiroides Bösenberg & Strand 1906, p243, pl. 12, figs. leg.; KOCHI PREF.: 2♂4♀, Nishitosakuchiyanai, Shiman- 291 (Holotype ♀ from Saga, Japan; not examined in this study). to-shi, 15-V-2019, R. Serita leg.; 1♀, Sagayama, Otoyo-cho,

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Fig. 3. Male palp. A–C, Theridiosoma epeiroides (specimen from Ibaraki Pref.); D–F, T. dissimulatum sp. nov. (holotype). A, D, ventrral view; B, E, post-ventral view; C, F, retrolateral view. Scales=0.1mm.

Nagaoka-gun, 4-VII-2020, R. Serita leg. + 0.26 + 0.43 + 0.31 + 0.15 = 1.75; III 0.4 + 0.21 + 0.22 + Diagnosis. Males and females of the species can be distin- 0.25 + 0.17 = 1.25/0.37 + 0.22 + 0.25 + 0.23 + 0.15 = 1.22; guished from the congeners except T. dissimulatum sp. nov. IV 0.49 + 0.23 + 0.36 + 0.35 + 0.17 = 1.60 / 0.56 + 0.22 + by the combination of the following characteristics: a long 0.32 + 0.34 + 0.25 = 1.69. Leg I length divided by carapace conductor projection and two embolic apophyses of male width 3.31/2.97. Abdomen 0.82/1.51 long; 0.94/1.56 wide; palp, epigynal plate of females with a pair of sclerotized 1.07/1.78 high. processes projecting toward the median. See the diagnosis Coloration and markings (Figs. 1A–D, 7A–D). Carapace section of T. dissimulatum sp. nov. for detailed information dark brown. Legs pale yellowish brown and darker anteriorly. of interspecific comparison. Pair of dark brown markings on lateral sides of abdomen with Description. Based on 1♂ and 1♀ from Ibaraki Pref. serrated edge, abdomen dorsum covered with white scale-like Measurements and morphology ♂/♀. Body 1.60/2.35 markings, black markings on center of posterior dorsum. long; carapace 0.74/0.78 long; 0.76/0.72 wide; 0.53/0.49 Genital organs. Male palp (Figs. 3A–C, 7E–H): paracym- high. Anterior eye row recurved and posterior eye row bium hook-like with blunt tip; tegulum bulbous with ventral straight in dorsal view. Eye size: AME 0.07/0.09; ALE side beneath posterior edge of embolic division strongly 0.07/0.07; PME 0.09/0.09; PLE 0.06/0.07. Distance between sclerotized with many folds; embolic division complex of eyes: AME–AME 0.01/0.01; AME–ALE 0.02/0.02; PME– apophysis covered with semitransparent conductor; em- PME 0.02/0.03; PME–PLE 0.04/0.05. Leg length: I 0.84 + bolus short and tubular; two bristle-like embolic apophyses 0.29 + 0.58 + 0.52 + 0.22 = 2.45/0.76 + 0.29 + 0.48 + 0.53 + running parallel, retrolateral one longer and prolateral one 0.26 = 2.32; II 0.61 + 0.25 + 0.43 + 0.39 + 0.21 = 1.89/0.60 shorter; posterior edge of embolic division strongly sclero-

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Fig. 4. Male palp. A–C, Theridiosoma paludicolum sp. nov. (holotype); D–F, T. fulvum sp. nov. (holotype); G–I, T. alboannulatum sp. nov. (holotype); A, D, G, ventral view; B, E, H, post-ventral view; C, F, I, retrolateral view. Scales=0.1mm.

tized with angular corners; conductor projection thin and als show light yellowish brown or uniformly dark brown sharp; median apophysis hook-like with sharp tip. Female abdomen (Figs. 13A–D). Range of carapace width 0.71– genitalia (Figs. 5A–B, 7I–J): epigyne with a pair of sclero- 0.80/0.65–0.80 (based on 13♂/18♀). tized processes (described as “spurs” in Coddington 1986) Distribution. Russia (Far East), Korea, Japan (Hokkaido projecting toward the median with tips of sharp and pointed to Kyushu). processes, interior edges of processes forming heart-shaped Habitat. This species inhabits wet and dim forests and is contour (Figs. 5A, 7I); copulatory ducts wider at openings frequently found in streams. and narrower toward spermathecae, running from ventral to dorsal side of spermathecae and bent inward before connect- Theridiosoma dissimulatum sp. nov. ing to them, pair of oval spermathecae close to each other [Japanese name: Nangoku-karakara-gumo] (Figs. 5B, 7J–L). (Figs. 1E–H, 3D–F, 5C–D, 8A–J, 9A–P, 13E–H) Variations. Variation in body color: some individu-

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Fig. 5. Female genitalia. A–B, Theridiosoma epeiroides (specimen from Ibaraki Pref.); C–D, T. dissimulatum sp. nov. (paratype from Amami-ohshima Is.); A, C, epigyne, ventral view; B, D, vulva, dorsal view. Scales=0.1mm.

Type materials. All the specimens were collected in leg.; 2♂4♀, Iriomote, 27-XII-1987 (1♂3♀), 3-I-1990 (1♀), Amami-shi, Kagoshima Pref., Japan by T. Hiramatsu. Holo- 3-I-1991 (1♂), A. Tanikawa leg.; 2♀, Ohhara, 30-IV-1990, type: ♂, Santarou-toge Pass, 22-VII-2014. Paratypes: 5♂6♀, A. Tanikawa leg.; 1♀, Sangara, Funaura, 15-VIII-1992, A. same data as the holotype (2♂6♀), Honcha-toge Pass, 20- Tanikawa leg.; 2♂1♀, Aira-gawa River, Komi, 23-VI-2012 VII-2014 (3♂). (1♂), 1-VII-2011 (1♂1♀), T. Hiramatsu leg.; 1♂, Ushi- Other specimens examined. All specimens were col- ku-mori, Iriomote, 6-V-2004, T. Hiramatsu leg. lected in Okinawa Pref., Japan. OKINAWA-JIMA ISLAND Diagnosis. In appearance, this species is slightly similar to T. (Kunigami-gun): 3♀, Janagusuku, Ogimi-son, 7-III-2020, epeiroides. However, the color pattern on carapace is different Y. Suzuki & R. Serita leg.; 1♀, Hiji, Kunigami-son, 8-III- between new species and T. epeiroides; color contrast in cephalic 2020, Y. Suzuki leg.; 1♀, Uka, Kunigami-son, 8-III-2020, region and thorax is much clear in the new species but uniformly R. Serita leg.; ISHIGAKI-JIMA ISLAND (Ishigaki-shi): dark brown in T. epeiroides (Figs. 1E vs. 1A; 1G vs. 1C; 8A vs. 2♂1♀, Mt. Omoto-dake, 30-III-2015, T. Hiramatsu leg.; 1♀, 7A; 8C vs. 7C). Males of the new species can be distinguished Tonoshiro, 25-VI-2012, T. Hiramatsu leg. IRIOMOTE-JI- from other Japanese congeners by a long conductor projection MA ISLAND (Taketomi-cho, Yaeyama-gun): 1♂, Sonai, and two embolic apophyses, except T. epeiroides, which have a 29-XII-1985, A. Tanikawa leg.; 1♂3♀, Komi, 30-XII-1985 similar assemblage of apophyses. Nevertheless, this species can (1♀), 1-IV-1989 (1♀), 1-V-1990 (1♂), A. Tanikawa leg., 23- clearly be differentiated from T. epeiroides by the conductor pro- VI-2012 (1♀), T. Hiramatsu leg.; 2♀, Haiminaka, 21-VIII- jection that is relatively short and not reaching the posterior edge 1987 (1♀), A. Tanikawa leg., 19-III-2019 (1♀), R. Serita of the tegulum; two same-length bristle-like embolic apophyses

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Fig. 6. Female genitalia. A–B, Theridiosoma paludicolum sp. nov. (paratype from Ibaraki Pref.); C–D, T. fulvum sp. nov. (paratype from Saitama Pref.); E–F, T. alboannulatum sp. nov. (paratype from Iriomote-jima Is.); A, C, E, epigyne, ventral view; B, D, F, vulva, dorsal view. Scales=0.1mm.

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Fig. 7. Theridiosoma epeiroides Bösenberg & Strand 1906 (specimens of Ibaraki Pref.). A, habitus of male, dorsal view; B, abdomen of male, lateral view; C, habitus of female, dorsal view; D, abdomen of female, lateral view; E, left male palp, ventral view; F, same, post-ventral view; G, same, retrolateral view; H, paracymbium, dorsal view; I, epigyne, ventral view; J, vulva, dorsal view; K, same, anterior view, L, same, lateral view. Arrows in Figs. E and F indicate posterior edge of embolic division. Scales=0.5mm (A–D), 0.1mm (E–L).

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Fig. 8. Theridiosoma dissimulatum sp. nov. (male holotype and one of female paratypes from Amami-ohshima Is.). A, habitus of male, dorsal view; B, abdomen of male, lateral view; C, habitus of female, dorsal view; D, abdomen of female, lateral view; E, left male palp, ventral view; F, same, post-ventral view; G, same, retrolateral view; H, paracymbium, dorsal view; I, epigyne, ventral view; J, vulva, dorsal view. Arrows in Figs. E and F indicate posterior edge of embolic division. Scales=0.5mm (A–D), 0.1mm (E–J).

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(while retrolateral one much longer in T. epeiroides); the posteri- Island shows a much clearer contrast in the color of the head or edge of tegulum beneath embolic apophyses is weakly sclero- and thorax (Figs. 9C–F), whereas the population on Irio- tized (while strongly sclerotized with many folds in T. epeiroides) mote-jima Island has an orange dorsum of the abdomen with (Figs. 3D–E vs. 3A–B; 8E–F vs. 7E–F). Females of the new a pair of large black spots on the anterior and posterior (Figs. species resemble T. epeiroides in shape of the epigyne: a pair of 9G–L, 13G). The shape of the epigyne varies slightly be- processes on the edge of the epigynal plate projecting towards tween populations and in the same locality, but the variation median and forming a unique heart-shaped contour, but can be is continuous (Figs. 9M–P), and the heart-shaped contour distinguished by the following characteristics: distance between formed by interior edges of genital processes is common in the processes is relatively narrower and tips of the processes are the females of this species. No clear difference was found blunt (Figs. 5C vs. 5A; 8I vs. 7I). in the internal structure of female genitalia between popula- Description. Based on the ♂ holotype and 1♀ paratype tions. Range of carapace width 0.46–0.62/0.53–0.70 (based from Amami–ohshima Island. on 7♂/18♀). Measurements and morphology ♂/♀. Body 1.13/2.10 Distribution. Japan (Kagoshima Pref.: Amami-ohshima; long; carapace 0.51/0.66 long; 0.51/0.63 wide; 0.38/0.36 Okinawa Pref.: Okinawa-jima, Ishigaki-jima, and Irio- high. Anterior eye row recurved and posterior eye row mote-jima Islands) straight in dorsal view. Eye size: AME 0.07/0.08; ALE Habitat. Although this species inhabits environments 0.07/0.07; PME 0.07/0.07; PLE 0.04/0.06. Distance between similar to those of T. epeiroides, both species have never eyes: AME–AME 0.01/0.01; AME–ALE 0.02/0.02; PME– been collected in the same locality. PME 0.02/0.02; PME–PLE 0.03/0.04. Leg length: I 0.67 + Etymology. The specific name means “disguising” in Lat- 0.24 + 0.44 + 0.36 + 0.25 = 1.96/0.74 + 0.28 + 0.46 + 0.46 + in and is derived from the wide variation in body color and 0.39 = 2.33; II 0.51 + 0.21 + 0.35 + 0.36 + 0.22 = 1.65/0.63 markings of the species (Fig. 9), which makes us believe + 0.24 + 0.37 + 0.40 + 0.21 = 1.85; III 0.32 + 0.17 + 0.17 + they are not conspecific. 0.21 + 0.13 = 1.00/0.32 + 0.20 + 0.20 + 0.25 + 0.14 = 1.11; IV 0.36 + 0.19 + 0.22 + 0.27 + 0.16 = 1.20 0.60 + 0.22 + Theridiosoma paludicolum sp. nov. 0.34 + 0.36 + 0.20 = 1.72. Leg I length divided by carapace [Japanese name: Minamo-karakara-gumo] width 3.84/3.70. Abdomen 0.60/1.41 long; 0.67/1.32 wide; (Figs. 2A–D, 4A–C, 6A–B, 10A–J, 13I–L) 0.82/1.38 high. Coloration and markings (Figs. 1E–H, 8A–D). ♂/♀. Car- Type materials. All the specimens were collected in apace pale yellowish brown with head darker. Eye region Ibaraki Pref., Japan, by Y. Suzuki. Holotype: ♂, Ukishima, dark brown. Legs pale yellowish brown and darker anterior- Inashiki-shi, 13-V-2020. Paratypes: 3♂5♀, same data as the ly. Abdomen pale yellowish brown with a pair of large dark holotype; 3♀, Teno-machi, Tsuchiura-shi, 22-V-2019. brown markings on anterior dorsum and large dark brown Other specimens examined. All specimens were col- marking on posterior dorsum, ventral side of abdomen dark lected in Japan. IBARAKI PREF.: 30♀, same data as the brown/dorsum of abdomen pale yellowish brown covered holotype; 1♀, Amakubo, Tsukuba-shi, 10-V-2020, Y. Suzuki with scaly and white markings, posterior dorsum darker, lat- leg.; 10♂5♀, Tennodai, Tsukuba-shi, 25-V-2020 (1♂4♀), eral side of abdomen dark brown with light brown spots. 3-VI-2020 (1♂), 24-VI-2020 (1♀), 4-VII-2020 (8♂), Y. Genital organs. Male palp (Figs. 3D–F, 8E–H): paracym- Suzuki leg.; 3♂8♀, Gakuen-minami, Tsukuba-shi, 27-V- bium hook-like with blunt tip; tegulum bulbous with ventral 2020 (3♂7♀), 7-VI-2020 (1♀). Y. Suzuki leg.; 1♀, Kangori, side beneath posterior edge of embolic division weakly Tsukuba-shi, 5-VI-2020, Y. Suzuki leg.; 2♂1♀, Oda, Tsuku- sclerotized; embolic division complex of apophysis covered ba-shi, 21-VII-2020, Y. Suzuki leg. CHIBA Pref.: 4♂29♀, with semitransparent conductor; embolus short and tubular; Tobari-shinden, Kashiwa-shi, 24-V-2020, Y. Suzuki leg. two bristle-like embolic apophyses running parallel; poste- KOCHI PREF.: 4♂10♀, Ryu, Usa-cho, Tosa-shi, 9-VII- rior edge of embolic division strongly sclerotized with an- 2020, R. Serita leg. gular corners; conductor projection thin and sharp; median Diagnosis. The new species is characterized by unique apophysis hook-like with sharp tip. Female genitalia (Figs. color and abdominal markings: a pair of large white mark- 5C–D, 8I–J): epigyne with a wide plate and pair of process- ings on the dark-colored dorsum of the abdomen (Figs. 2A– es with brunt tips projecting toward median, interior edges D, 10A–D). Males of the new species are similar to that of T. of processes forming heart-shaped contour; pair of oval fulvum as follows: three bristle-like embolic apophyses are spermathecae close to each other; copulatory ducts running visible, with the retrolateral one covered with semi-transpar- from ventral to dorsal side of spermathecae and connected ent membrane (Figs. 4A–B, 10E–H); it can be distinguished to them; fertilization ducts running dorsal side of copulatory from T. fulvum by the thin and weakly curved conductor ducts. projection (Figs. 4A–B vs. 4D–E; 10E–F vs. 11E–F); the Variations. This species shows wide variations in body shortest embolic apophysis is not parallel to others but has color and markings between populations on islands, al- the prolateral tip (Figs. 10E–F vs. 11E–F); and posterior though the morphology of the male palps is consistent (Figs. edge of embolic division flat (Figs. 4B vs. 4E; 10F vs. 11F, 9, 13E–H). For example, the population on Okinawa-jima arrows). Females are also similar to T. fulvum sp. nov. but

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Fig. 9. Variations in the habitus and epigyne of Theridiosoma dissimulatum sp. nov. A–B, M, specimens of Amami-ohshima Is., C–F, N–O, specimens of Okinawa-jima Is., G–J, P, specimens of Ishigaki-jima Is., K–L, specimens of Iriomote-jima Is. A G, H, habitus of male; B–F, I–L, habitus of female, M–P, epigyne. Scales=0.5mm (A–L), 0.1mm (M–P).

can be distinguished from the latter by the shape of the con- Measurements and morphology ♂/♀. Body 0.98/1.64 tour formed by the interior edges of processes on the pos- long; carapace 0.45/0.60 long; 0.44/0.53 wide; 0.36/0.36 terior edge of the genital plate: rounded and drop-shaped in high. Eye size: AME 0.05/0.06; ALE 0.05/0.05; PME T. paludicolum sp. nov. and somewhat cornered and shaped 0.06/0.05; PLE 0.04/0.05. Distance between eyes: AME– like a bottle-opener head in T. fulvum sp. nov. (Figs. 6A vs. AME 0.02/0.02; AME–ALE 0.02/0.02; PME–PME 6C; 10I vs. 11I). 0.02/0.02; PME–PLE 0.02/0.03. Leg lengths: I 0.47 + 0.18 Description. Based on ♂ holotype and 1♀ paratype from + 0.31 + 0.29 + 0.20 = 1.45/0.58 + 0.21 + 0.33 + 0.31 + 0.23 Ibaraki Pref. = 1.66; II 0.38 + 0.17 + 0.26 + 0.23 + 0.16 = 1.20/0.45 +

Fig. 10. Theridiosoma paludicolum sp. nov. (male holotype and a female of paratypes from Ibaraki Pref.). A, habitus of male, dorsal view; B, abdomen of male, lateral view; C, habitus of female, dorsal view; D, abdomen of female, lateral view; E, left male palp, ventral view; F, same, post-ventral view; G, same, retrolateral view; H, paracymbium, dorsal view; I, epigyne, ventral view; J, vulva, dorsal view. Arrows in Figs. E and F indicate posterior edge of embolic division. Scales=0.25mm (A–B), 0.5mm (C–D), 0.1mm (E–J).

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Fig. 11. Theridiosoma fulvum sp. nov. (male holotype and one of female paratypes from Saitama Pref.). A, habitus of male, dorsal view; B, abdomen of male, lateral view; C, habitus of female, dorsal view; D, abdomen of female, lateral view; E, left male palp, ventral view; F, same, post-ventral view; G, same, retrolateral view; H, paracymbium, dorsal view; I, epigyne, ventral view; J, vulva, dorsal view. Arrows in Figs. E and F indicate posterior edge of embolic division. Scales=0.5mm (A–D), 0.1mm (E–J).

Fig. 12. Theridiosoma alboannulatum sp. nov. (male holotype and one of female paratypes from Iriomote-jima Is.). A, habitus of male, dorsal view; B, abdomen of male, lateral view; C, habitus of female, dorsal view; D, abdomen of female, lateral view; E, left male palp, ventral view; F, same, post-ventral view; G, same, retrolateral view; H, paracymbium, dorsal view; I, epigyne, ventral view; J, vulva, dorsal view. Arrows in Figs. E and F indicate posterior edge of embolic division. Scales=0.5mm (A–D), 0.1mm (E–J).

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Fig. 13. Habitus of Theridiosoma species when alive. A, T. epeiroides, male (Ibaraki Pref.); B–C, same, female (Ibaraki Pref.); D, same, female (Tokyo); E, T. dissimulatum sp. nov., female (Amami-ohshima Is.); F same, female (Okinawa-jima Is.); G–H, same, female (Iriomote-jima Is.); I, T. paludicolum, male (Chiba Pref.); J, same, male lacking white markings on abdomen (Kochi Pref.); K, same, female (Chiba Pref.); L, same, female with light brown colored body (Kochi Pref.); M, T. fulvum, male and female (Ibaraki Pref.); N, same, female (Saitama Pref.), O, same, female with light colored markings on abdomen (Ibaraki Pref.). P, T. alboannulatum sp. nov., female (Iriomote-jima Is.). Note that all the photographs are not identical to type materials except that of T. alboannulatum (paratype female).

0.21 + 0.26 + 0.26 + 0.22 = 1.40; III 0.26 + 0.12 + 0.14 + tral dorsum along dorsolateral side. 0.15 + 0.14 = 0.81/0.29 + 0.14 + 0.17 + 0.20 + 0.20 = 1.00; Genital organs. Male palp (Figs. 4A–C, 10E–H): para- IV 0.36 + 0.15 + 0.21 + 0.20 + 0.15 = 1.07/0.48 + 0.19 + cymbium hook-like with blunt tip; tegulum bulbous with 0.28 + 0.24 + 0.19 = 1.38. Leg I length divided by carapace ventral side beneath posterior edge of embolic division width 3.30/3.13. Abdomen 0.52/1.07 long; 0.55/1.07 wide; weakly sclerotized; embolic division complex of apophysis 0.68/1.21 high. covered with semitransparent conductor; embolus short and Coloration and markings (Figs. 2A–D, 10A–D). ♂/♀. tubular; three bristle-like embolic apophyses visible; retro- Carapace pale whitish brown/pale yellowish brown with lateral one with wide semitransparent membrane, median center stained by dark markings. Eye region black. Legs one longer; prolateral one as long as retrolateral one, tips of pale whitish brown/pale yellowish brown and darker anteri- these apophyses heading to different directions to each other. orly. Abdomen with pair of white markings on anterior dor- Posterior edge of embolic division sclerotized with angular sum with pair of dark brown markings on anterolateral side; corners, basal edge straight at the post-ventral view; con- posterior dorsum and ventral side of abdomen dark brown/ ductor projection thin, slightly curved at the ventral view; dark brown with pair of white markings running from cen- median apophysis hook-like with sharp tip. Female genitalia

(Figs. 6A–B, 10I–J): epigyne with a plate having a pair of species of the genus except T. paludicolum sp. nov. by the sclerotized processes projecting posteriorly, interior edges combination of the following characteristics: three bris- of processes forming rounded and drop-shaped contour; pair tle-like embolic apophyses of the male palp are visible, with of spermathecae longer than wide and close to each other, the retrolateral one covered with semi-transparent membrane copulatory ducts running from ventral to dorsal side of sper- (Figs. 4D–F, 11E–H), and the epigyne has a pair of sclero- matheca and connected to spermathecae; fertilization ducts tized processes projecting posteriorly (Figs. 6C, 11I). See running dorsal side of copulatory ducts. the diagnosis section of T. paludicolum sp. nov. for detailed Variations. This species shows variations in body color information of interspecific comparison. and markings; some males lack a pair of dark brown mark- Description. Based on ♂ holotype and 1♀ paratype from ings on the dorsum of the abdomen, and some females have Saitama Pref. a light brown abdomen (Figs. 13I–L). Range of carapace Measurements and morphology ♂/♀. Body 1.41/1.58 width 0.40–0.60/0.42–0.64 (based on 14♂/11♀). long; carapace 0.60/0.65 long; 0.61/0.64 wide; 0.41/0.40 Distribution. Japan (Ibaraki Pref., Chiba Pref., Kochi high. Eye size: AME 0.07/0.07; ALE 0.07/0.07; PME Pref.) 0.07/0.07; PLE 0.05/0.05. Distance between eyes: AME– Habitat. This species inhabits marshes, shores of lakes, AME 0.02/0.02; AME–ALE 0.01/0.02; PME–PME and ponds covered with common reeds, and it is collected 0.02/0.02; PME–PLE 0.04/0.03. Leg lengths: I 0.73 + 0.26 beside the water surface. + 0.51 + 0.47 + 0.29 = 2.26/0.66 + 0.26 + 0.42 + 0.34 + Etymology. The specific name means “inhabiting wet- 0.27 =1.95; II 0.59 + 0.23 + 0.39 + 0.38 + 0.27 = 1.86/0.53 lands” in Latin and is derived from its natural habitat. + 0.24 + 0.36 + 0.34 + 0.24 = 1.72; III 0.36 + 0.18 + 0.20 + 0.26 + 0.19 = 1.19/0.32 + 0.19 + 0.19 + 0.24 + 0.20 = 1.14; Theridiosoma fulvum sp. nov. IV 0.48 + 0.21 + 0.29 + 0.28 + 0.20 = 1.46/0.54 + 0.22 + [Japanese name: Ameiro-karakara-gumo] 0.34 + 0.31 + 0.21 = 1.62. Leg I length divided by carapace (Figs. 2E–H, 4D–F, 6C–D, 11A–J, 13M–O) width 3.70/3.05. Abdomen 0.76/0.93 long; 0.80/0.91 wide; 1.01/1.12 high. Type series. All the specimens were collected in Miya- Coloration and markings (Figs. 2E–H, 11A–D). Carapace dera, Iruma-shi, Saitama Pref., Japan, by T. Hiramatsu. Ho- yellowish brown but turned to pale yellowish brown in etha- lotype: ♂, 31-V-2020; Paratypes: 3♂11♀, same data as the nol, eye region black. Legs pale yellowish brown. Abdomen holotype (2♀), 29-VI-2016 (4♀), 4-VI-2018 (3♂1♀), 25-V- dark yellowish brown but yellowish brown with posterior 2020 (4♀). dorsum darker, ventral side of abdomen dark brown. Other specimens examined. All specimens were collect- Genital organs. Male palp (Figs. 4D–F, 11E–H): paracym- ed in Japan. HOKKAIDO: 1♀, Utonaikita, Tomakomai-shi, bium hook-like with pointed tip; tegulum bulbous with ven- 1-VIII-2019, R. Serita leg. FUKUSHIMA PREF.: 2♀, tral side beneath posterior edge of embolic division weakly Tanawaki, Obama, Soma-shi, 12-VII-2020, Y. Suzuki leg.; sclerotized; embolic division complex of apophysis covered 1♂, Kinsho-ji, Shirakawa-shi, 13-VII-2020, Y. Suzuki leg.; with semitransparent conductor; embolus short and tubular; 2♂13♀, Osaka-yama, Shirakawa-shi, 14-VII-2020, Y. Su- three bristle-like embolic apophyses visible, retrolateral one zuki leg. IBARAKI PREF.: 9♂4♀, Tennodai, Tsukuba-shi, with wide semitransparent membrane, median one longer, 25-V-2020 (4♀6♂), 26-V-2020 (2♂), 4-VII-2020 (1♂), prolateral one as long as retrolateral one and parallel to the Y. Suzuki leg.; 4♂5♀, Kangori, Tsukuba-shi, 5-VI-2020 latter; posterior edge of embolic division sclerotized with (3♂5♀), 15-VI-2020 (1♂), Y. Suzuki leg.; 1♀, Ueno, Tsuku- corners angular, straight at the post-ventral view; conduc- ba-shi, 20-VII-2020, T. Suzuki leg.; 1♀, Oda, Tsukuba-shi, tor projection thin, slightly curved at ventral view; median 21-VII-2020, Y. Suzuki leg.; 1♂1♀, Osawa, Daigo-machi, apophysis hook-like with sharp tip. Female genitalia (Figs. Kuji-gun, 22-VII-2020, Y. Suzuki leg.; 1♂5♀, Kamifuruu- 6C–D, 11I–J): epigyne with a plate having a pair of sclero- chi, Shirosato-machi, Higashi-ibaraki-gun, 5-VII-2020, Y. tized processes projecting posteriorly, interior edges of pro- Suzuki leg. TOCHIGI PREF.: 1♀, Motegi-machi, Haga-gun, cesses forming somewhat cornered and bottle-opener-shaped 5-VII-2020, Y. Suzuki leg. GUNMA PREF.: 2♂2♀, Yosh- contour; pair of spermathecae oval and close to each other; ioka-cho, 14-V-2020 (1♂2♀, collected as juveniles and ma- copulatory ducts running from ventral side of spermathecae tured on 30-V-2020), 30-V-2020 (1♂), S. Nagai leg. CHIBA to dorsal side and connected to them; fertilization ducts run- PREF.: 3♂4♀, Toda, Sanmu-shi, 19-VIII-2020, Y. Suzuki ning dorsal side of copulatory ducts. leg.; 5♀, Iwatomi, Sakura-shi, 19-VIII-2020, Y. Suzuki leg. Variations. This species shows variations in color and SAITAMA PREF.: 3♀1♂, Mt. Tenran-zan, Hanno-shi, 4-VI- markings on the abdomen: some specimens with a pair of 2017 (2♀1♂), T. Hiramatsu leg, 7-VII-2019 (1♀), R. Serita light whitish yellow markings on the dorsum of abdomen or leg. KOCHI PREF.: 4♀1♂, Nino, Haruno-cho, Kochi-shi, with dark brown abdomen (Figs. 13M–O). Although most 6-VI-2020, R. Serita leg.; 1♀, Nyuta, Shimanto-shi, 2-IX- specimens have no clear markings on carapace, specimens 2020, R. Serita leg.; TOTTORI PREF.: 1♀, Shimonakatani, from Kochi Pref. present carapaces stained with dark brown Nanbu-cho, Saihaku-gun, 24-VIII-2020, Y. Obae leg. spots. Range of carapace width 0.55–0.65/0.56–0.66 (based Diagnosis. This species can be distinguished from other on 17♂/27♀).

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Distribution. Japan (Hokkaido, Fukushima Pref., Ibara- yellowish brown with darker anterior. Abdomen dark brown ki Pref., Tochigi Pref., Gunma Pref., Chiba Pref., Saitama but turned to yellowish brown in ethanol with pale colored Pref., Kochi Pref., Tottori Pref.) annular (ring-shaped) marking along dorsum and dorsolater- Habitat. This species was collected from wetlands cov- al side in both sexes and pair of whitish markings on anteri- ered with riparian grasses and wet bushes on riverbeds. or dorsum in females. Etymology. The specific name indicates “amber-colored” Genital organs. Male palp (Figs. 4G–I, 12E–H): para- in Latin and is derived from the coloration of the new spe- cymbium hook-like with pointed tip; tegulum bulbous with cies. ventral side beneath posterior edge of embolic division weakly sclerotized and lacking folds; embolic division Theridiosoma alboannulatum sp. nov. moderately complex and covered with semitransparent con- [Japanese name: Shirowa-karakara-gumo] ductor; embolus short and tubular; two bristle-like embolic (Figs. 2I–L, 4G–I, 6E–F, 12A–J, 13P) apophyses visible and running parallel; posterior edge of embolic division sclerotized with retrolateral corner angular Type materials. All specimens were collected in Okina- and prolateral one rounded; conductor projection absent; wa Pref., Japan. Holotype: ♂, Komi, Taketomi-cho, Yae- median apophysis hook-like with sharp tip. Female genitalia yama-gun, 19-III-2019, T. Hiramatsu leg., Paratypes:2♀, (Figs. 6E–F, 12I–J): epigyne with plate lacking sclerotized Haiminaka, Taketomi-cho, Yaeyama-gun, 5-V-2018, T. Hi- processes, bluntly triangular with lateral corners angular; ramatsu leg.; 1♂, same data as the holotype; 2♀, Nishihara, pair of spermathecae oval and close to each other, copulato- Hirara, Miyakojima-shi, 3-III-2016, T. Suguro leg. ry ducts wide, running from ventral side of spermathecae to Diagnosis. This species is characterized by markings and dorsal side and connected to them, following a simple curve; body color: dark brown markings along cervical grooves fertilization ducts running dorsal side of copulatory ducts. on carapace and pale colored annular (ring-shaped) mark- Variations. Range of carapace width 0.38–0.40/0.49–0.66 ings on the abdomen (Figs. 2I–L, 12A–D). The male palp (based on 2♂/4♀). is slightly similar to that of T. caaguara Rodrigues & Ott Distribution. Japan (Miyako-jima and Iriomote-jima Is- 2005b, T. esmeraldas Dupérré & Tapia 2017, T. circuloar- lands) genteum Wunderlich 1976, and T. taiwanica Zhang, Zhu & Habitat. This species was collected in various environ- Tso 2006 in lacking a conductor projection but distinguished ments, such as wet grasslands, wetlands, and the edges of by the presence of two parallel embolic apophyses. The fe- woods. male genitalia of the new species is slightly similar to that of Etymology. The specific name means “having white T. chiripa Rodrigues & Ott 2005a and T. taiwanica in lack- rings” in Latin and was derived from the abdominal marking sclerotized processes, and the edge of the genital plate ings. posteriorly curved, distinguished by angular lateral corners Acknowledgments of genital plate, with the genitalia longer than the width (distance between posterior edge of genital plate and anteri- We wish to express our heartfelt thanks to Mr. Masamichi Nagai, or edge of spermathecae is longer than the width of genital Mr. Yuito Obae, Dr. Akio Tanikawa, and Mr. Tatsumi Suguro for offer- ing us valuable specimens; Mr. Gomei Yoda, Mr. Ryosuke Matsushi- plate) in the new species (Figs. 6E, F; 12I, J; Rodrigues & ma, Mr. Shigeyuki Yoshii, and Mr. Toshimasa Mitamura for their sup- Ott 2005a; Zhang et al. 2006). port with field surveying; Mr. Masaru Hasegawa at the Saitama Green Description. Based on the ♂ holotype and 1♀ paratype Museum for allowing us to collect the specimens; Mr. Toru Usui and from Iriomote-jima Island. Mr. Ryoichi Tsushima at the Investigation Committee for Endangered Measurements and morphology ♂/♀. Body 0.98/1.49 Animal Species in Saitama Pref. for providing us with the opportunity to conduct a survey on T. fulvum sp. nov.; and the Tosa City Board of long; carapace 0.40/0.66 long; 0.40/0.49 wide; 0.34/0.45 Education, Kochi Pref., for permitting us to collect specimens at the high. Eye size: AME 0.05/0.06; ALE 0.05/0.05; PME wetland owned by Meitoku Gijuku Junior and Senior High Schools. 0.06/0.07; PLE: 0.04/0.05. Distance between eyes: AME– We would like to thank Editage (www. editage.jp) for English lan- AME 0.01/0.01; AME–ALE 0.01/0.02; PME–PME guage editing and two anonymous reviewers for their invaluable com- 0.01/0.01; PME–PLE 0.02/0.01. Leg lengths: I 0.45 + 0.16 ments on our manuscript. + 0.28 + 0.24 + 0.18 = 1.31/0.51 + 0.20 + 0.34 + 0.31 + 0.23 References = 1.59; II 0.36 + 0.14 + 0.24 + 0.21 + 0.17 = 1.12/0.45 + Coddington, J. A. 1986. The genera of the spider family Theridioso- 0.19 + 0.27 + 0.26 + 0.21 = 1.38; III 0.22 + 0.12 + 0.12 + matidae. Smithson. Contrib. Zool., 422: 1–96. 0.13 + 0.10 = 0.69/0.29 + 0.14 + 0.14 + 0.15 + 0.13 = 0.85; Dupérré, N. & Tapia, E. 2017. On some minuscule spiders (Araneae: IV 0.36 + 0.13 + 0.15 + 0.14 + 0.12 = 0.90/0.40 + 0.17 + Theridiosomatidae, Symphytognathidae) from the Chocó region of 0.21 + 0.23 + 0.17 = 1.18. Leg I length divided by carapace Ecuador with the description of ten new species. Zootaxa, 375–399. Miller, J. A., Griswold, C. E. & Yin, C. M. 2009. The symphytogna- width 3.28/2.41. Abdomen 0.45/1.01 long; 0.57/1.12 wide; thoid spiders of the Gaoligongshan, Yunnan, China (Araneae, Ara- 0.68/1.20 high. neoidea): Systematics and diversity of micro-orbweavers. ZooKeys, Coloration and markings (Figs. 2I–L, 12A–D, 13P). Car- 11: 9–195. apace yellowish brown but turned to pale whitish brown in Koch, L. 1877. Verzeichniss der bei Nürnberg bis jetzt beobachteten ethanol, dark brown markings along cervical grooves. Legs Arachniden (mit Ausschluss der Ixodiden und Acariden) und Besch-

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