Sinocanthium Yu & Li, 2020

Zhang, Jianshuang, Yu, Hao & Li, Shuqiang, 2020, New cheiracanthiid spiders from Xishuangbanna rainforest, southwestern China (Araneae, Cheiracanthiidae), ZooKeys 940, pp. 51-77 : 51

Sinocanthium Yu & Li gen. nov.

Type species.

Sinocanthium shuangqiu Yu & Li, sp. nov.

Etymology.

The generic name is derived from its similarity to Cheiracanthium and the Latin adjective Sino- for Chinese referring to the distribution region of the genus. The gender is neuter.

Diagnosis.

Sinocanthium gen. nov. resembles Cheiracanthium by the similar habitus (Figs 11A, B , 4G, H , 6A, B ) but is consistently separable by the shape of the epigyne. Sinocanthium gen. nov., as in most Cheiracanthium species, has a yellow body, a wide cephalic part, long legs, subequal eyes, and parallel eye rows of equal width occupying the greater width of the head. It can be distinguished from Cheiracanthium sensu lato by the absence of copulatory ducts (Fig. 11E, G ) (vs. copulatory ducts with variable lengths but distinct in all Cheiracanthium species, including C. daofeng sp. nov., C. duanbi sp. nov., and C. wuquan sp. nov. (Figs 2C, D , 4C, D , 6E, G ), and by the atrium located anteriorly with a rebordered posterior margin (Figs 11C, D, F ) (vs. atrium located anteriorly or centrally, atrial hood located anteriorly in Cheiracanthium ).

Description.

Same as for the species.

Composition.

Type species only.

Comments.

Based on the original figures and text descriptions of the epigynes, Cheiracanthium sensu lato can be further divided into at least four or five different taxa ( Wunderlich 2012). The morphology of the epigyne exhibits very high diversity. However, all Cheiracanthium species related to the generotype have copulatory ducts, even though the shapes, lengths, and courses of the copulatory ducts are variable. Despite the variable shapes, the atria of the different taxa are located posteriorly or centrally and are usually rebordered anteriorly and laterally. Obviously, Sinocanthium shuangqiu sp. nov. cannot be placed in Cheiracanthium sensu lato because of the peculiar structure of the epigyne, so we described a new genus to accommodate it. Although we examined only one female of S. shuangqiu sp. nov., our specimen is strikingly different from all Cheiracanthium species: The atrium is located anteriorly, the atrial posterior margin is rebordered, and copulatory ducts are absent, supporting our decision.

Figures

Figure 2. Cheiracanthium daofeng sp. nov., female paratype and male holotype. A Epigyne, intact, ventral view B epigyne, cleared, ventral view C vulva, cleared, dorsal view D vulva, cleared and embedded in Arabic gum, dorsal view E male habitus, dorsal view F male habitus, lateral view G female habitus, dorsal view H female habitus, ventral view. Abbreviations: A = atrium; AAM = atrial anterior margin; CD = copulatory duct; CO = copulatory opening; FD = fertilization duct; R = receptacle. Scale bars: 0.2 mm (A-D); 1 mm (E-H).

Figure 4. Cheiracanthium duanbi sp. nov., female paratype and male holotype. A epigyne, intact, ventral view B epigyne, cleared, ventral view C vulva, cleared, dorsal view D vulva, cleared and embedded in Arabic gum, dorsal view E male habitus, dorsal view F male habitus, lateral view G female habitus, dorsal view H female habitus, ventral view. Abbreviations: A = atrium; AAM = atrial anterior margin; CD = copulatory duct; CO = copulatory opening; FD = fertilization duct; R = receptacle. Scale bars: 0.2 mm (A-D); 1 mm (E-H).

Figure 6. Cheiracanthium wuquan sp. nov., female holotype. A Habitus, dorsal view B habitus, ventral view C epigyne, intact, ventral view D epigyne, cleared, ventral view E vulva, cleared, dorsal view F epigyne, cleared and embedded in Arabic gum, ventral view G vulva, cleared and embedded in Arabic gum, dorsal view. Abbreviations: A = atrium; AAM = atrial anterior margin; CD = copulatory duct; CO = copulatory opening; FD = fertilization duct; R = receptacle. Scale bars: 1 mm (A, B); 0.2 mm (C-G).

Figure 11. Sinocanthium shuangqiu sp. nov., female holotype. A habitus, dorsal view B habitus, ventral view C epigyne, intact, ventral view D epigyne, cleared, ventral view E vulva, cleared, dorsal view F epigyne, cleared and embedded in Arabic gum, ventral view G vulva, cleared and embedded in Arabic gum, dorsal view. Abbreviations: A = atrium; AAM = atrial anterior margin; APM = atrial posterior margin; CO = copulatory opening; FD = fertilization duct; R = receptacle. Scale bars: 1 mm (A, B); 0.2 mm (C-G).