Trachelas crewsae, Marusik & Fomichev, 2020

Marusik, Yuri M. & Fomichev, Alexander A., 2020, A new species of Trachelas L. Koch, 1872 (Araneae, Trachelidae) from Tajikistan, ZooKeys 993, pp. 27-34 : 27

Trachelas crewsae sp. nov. Figs 1 , 2 , 3A-F , 4B , 5

Type material.

Holotype: ♂ (ZMMU), TAJIKISTAN: Khatlon Region; Tigrovaya Balka Reserve; 37°21'20.6"N, 68°28'12.4"E; tugai (gallery) forest with thick litter; 06.05.2015 (Y.M. Marusik). Paratype: 1♀ (ZMMU) together with the holotype.

Diagnosis.

The male of the new species resembles those of T. vulcani in having a similar long, coiled embolus and long, apically oriented patellar apophysis (Pa) but can be distinguished from it by having a distinct abdominal scutum occupying 2/3 of the abdomen length (vs. absent) (cf. Figs 1A, B and 4A ), the patellar apophysis (Pa) with almost parallel edges (vs. triangular), the Ͻ-shaped sperm duct (Sd) (vs. J-shaped) and the haematodocha (Hd) being almost as wide as the tegulum in ventral view (vs. significantly narrower) (cf. Figs 2B-D, F , 3B and 4D ). Males of both species are also distinguishable in the relative length/width ratio of the palpal femur (as long as cymbium in the new species vs. shorter than cymbium) (cf. Fig. 4B, C ), and the much longer embolus with its base situated postero-retrolaterally vs. antero-prolaterally. The female of T. crewsae sp. nov. also resembles that of T. vulcani in having copulatory ducts packed in several coils and primary receptacles (Pr), consisting of two subunits, but can be separated from the latter by the copulatory openings (Co) situated laterally (vs. anteriorly) (cf. Fig. 3D, G ), the copulatory ducts (Cd) packed in four tight coils (vs. three loose coils) and the secondary receptacles (Sr) directed posteriad (vs. anteriolaterad) (cf. Fig. 3E, F, H ). Both sexes of T. crewsae sp. nov. differ reliably from those of T. vulcani in having an abdominal colour pattern formed by transverse dark grey stripes (cf. Figs 1A-F , 4A ).

Description.

Male (holotype). Total length 2.55. Carapace: 1.27 long, 1.07 wide. Carapace dark brown, granulated. Chelicerae and labium brown. Sternum yellow-orange. Maxillae light brown. Palps and legs yellow. Abdomen yellow-beige, with elongate scutum occupying 2/3 of abdomen; with dark grey dorsal pattern formed by transverse stripes; venter with epigastral scutum occupying whole ventral surface; book lung opercula large; postgaster with broad light band bordered with black lateral stripes. Spinnerets light yellow (Fig. 1A-C ). Measurements of legs. I: 0.89, 0.37, 0.73, 0.56, 0.43 (2.98). II: 0.83, 0.36, 0.69, 0.53, 0.41 (2.82). III: 0.64, 0.3, 0.47, 0.5, 0.29 (2.2). IV: 0.93, 0.31, 0.79, 0.8, 0.34 (3.17).

Palp as in Figs 2A-F , 3A-C , 4B ; femur as long as cymbium, three times longer than wide, with wide ventral groove (Fg) occupying an anterior third of segment; patellar apophysis finger-like as long as patella’s width, with a pointed tip; tegulum expanded anteriorly; Ͻ-shaped sperm duct poorly visible; embolus (Em) long, whip-like, coiled almost across entire tegulum; tegular apophysis (Ta) small, claw-shaped.

Female. Total length 2.7. Carapace: 1.2 long, 1.06 wide. Coloration as in the male, with lighter dorsal abdominal pattern (Fig. 1D-F ). Measurements of legs: I: 0.86, 0.37, 0.67, 0.53, 0.41 (2.84). II: 0.79, 0.36, 0.64, 0.51, 0.39 (2.69). III: 0.64, 0.31, 0.47, 0.49, 0.27 (2.18). IV: 0.93, 0.33, 0.81, 0.8, 0.34 (3.21).

Epigyne as in Fig. 3D-F ; epigynal plate semitransparent, through which the copulatory ducts and primary receptacles are clearly visible; fovea divided by septum ‘db’ shaped; copulatory openings small, located at anteriorly on fovea; copulatory ducts, forming four coils, packed in helix directed posteriolaterad; connecting ducts (Cn) looped; secondary receptacles small; primary receptacles consisting of two subunits, connected by a narrow constriction; fertilization ducts (Fd) weakly sclerotized.

Etymology.

The new species is named after our colleague Sarah C. Crews (San Francisco, USA), who continuously helps us with editing the English and providing fruitful comments on our manuscripts.

Distribution.

Known only from the type locality (Fig. 5A-C ).

Figures

Figure 1. Trachelas crewsae sp. nov.: A-C, G, I male D-F, H female A-F habitus, dorsal, lateral and ventral G-H cephalic part, dorsal I carapace left side. Scale bars: 0.5 mm (A-F), 0.1 mm (G-I).

Figure 2. Male palp of Trachelas crewsae sp. nov.: A-D terminal part, prolateral, ventral, retrolateral, dorsal F whole palp, retrolateral E femur, ventral. Abbreviations: C 2 coil 2, Hd haematodocha, Eb embolic base, Em embolus, Fg femoral groove, Pa patellar apophysis, Sd sperm duct, Ta tegular apophysis. Scale bars: 0.1 mm.

Figure 3. Male palp (A-C) and epigyne (D-H) of Trachelas crewsae sp. nov. (A-F) and T. vulcani (G-H) A prolateral B, D, G ventral C retrolateral E, H dorsal F lateral. Abbreviations: C 2 coil 2, Cd copulatory duct, Cn connecting duct, Co copulatory opening, Hd haematodocha, Eb embolic base, Em embolus, Fd fertilization duct, Fo fovea, Pa patellar apophysis, Pr primary receptacle, Sr secondary receptacle, Ta tegular apophysis. Scale bars: 0.1 mm.

Figure 4. Trachelas vulcani (A, C-D from Guangxi, China) and T. crewsae sp. nov. (B) A male habitus, dorsal B-C male palp, prolateral D male palp, ventral. A, C-D courtesy of Feng Zhang. Abbreviations: C 1 coil 1 of embolus, Eb embolic base, Hd haematodocha. Scale bars: 0.5 mm (A), 0.1 mm (B-D).

Figure 5. Distributional records of Trachelas crewsae sp. nov. and T. vulcani (A) and habitat of T. crewsae sp. nov. (B-C). Circle - T. crewsae sp. nov., diamond - type locality of T. vulcani, triangle - recent findings of T. vulcani outside of the type locality B Tigrovaya Balka Reserve C tugai (gallery) forest B-C courtesy of R. V. Yakovlev.