Brachythele rhodopensis, Dimitrov & Zonstein, 2022

Dimitrov, Dragomir & Zonstein, Sergei, 2022, A taxonomic contribution to the genus Brachythele Ausserer, 1871 (Araneae, Nemesiidae) with a description of a new species from Rhodope Mountains, Bulgaria, Zootaxa 5159 (4), pp. 583-592 : 584

Brachythele rhodopensis sp. n.

Figs 1–9 , 13–15

Type material. Male holotype, Bulgaria, Eastern Rhodope Mountains, near the town of Madzharovo ( GPS coordinates: 41.65, 25.84), 04.05.2021, leg. Dragomir Dimitrov ( SMF) .

Etymology. Named after the Rhodope Mountains ( Bulgaria), where the holotype was collected.

Diagnosis. The male is morphologically similar to those of Brachythele langourovi Lazarov, 2005 and Brachythele bentzieni Zonstein 2007 , in the presence of an embolic keel ( Figs 7–8 ). It can be distinguished by (1) the shape of the keel being more massive than in the other 2 species, and (2) the shape of the embolic portion—stout, curved ( Figs 7–9 , 13–15 ), whereas, in B. langourovi , it is curved but thinner ( Figs 10–12 ) and, in B. bentzieni , it is straight ( Figs 26–27 ).

Description. (Holotype male). Measurements: Total length 12.76; carapace length 6.30, width 4.70; sternum length 3.07, width 2.25; labium length 0.64; maxilla length 2.02; abdomen length 6.46, width 3.25; PMS length 0.62; PLS length 2.10. Palp. Femur length 2.31, patella length 1.16, tibia length 1.85, cymbium length 0.86, bulbus length 1.21. Leg measurements: I—15.45 (3.90, 2.84, 2.79, 3.35, 2.57), II—14.18 (4.09,7 2.52, 2.70, 2.89, 1.98), III—14.99 (3.94, 2.30, 2.54, 3.56, 2.65), IV—18.73 (4.16, 2.91, 4.22, 4.74, 2.70). Eyes’ diameters: ALE 0.22, AME 0.18, PLE 0.18, PME 0.175. Eyes’ interdistances: AME–AME 0.15, AME–ALE 0.11, ALE–PLE 0.10, PME–PME 0.39, PME–PLE 0.10.

Color ( Fig. 1 ). Carapace brown, with darker margins ( Figs 1–2 ). Legs more or less the same color as carapace. Sternum and coxae yellow-brown, coxae lighter ventrally. Sternal sigilla small and rounded, the posterior pair well visible, the other 2 much lighter ( Fig 3 ). Chelicerae dark brown. Abdomen beige with darker brownish pattern ( Fig 1 ). Spinnerets light beige ( Fig 4 ).

Eyes. Eye region darker than surrounding dorsal surface of carapace, elevated. Eyes compact. Anterior eye row procurved, posterior one almost straight (as seen from dorsal side, Figs 1–2 ).

Other somatic characters. Carapace dorsally covered with fine setae. Fovea visible, deep, recurved. Chelicerae with 8 promarginal teeth, dorsally covered with long, weak, dense setae. Maxillae with many small prolateral cuspules on basal part ( Fig 3 ). Tibia I with distal spur bearing 2 strong spines ( Figs 5–6 ). Scopula: distal on metatarsi, and entire on tarsi I–II; apical on tarsi III–IV. Trichobothria in 2 rows of 7–10 on tibiae and 9–11 on metatarsi. Paired claws with 7 teeth. PMS medium-sized; apical segment of PLS triangular.

Palp ( Figs 7–9 , 13–15 ). Femur, patella, and cymbium spineless. Tibia with 2 long dorsal spines. Bulbus pearshaped; apical part protruding, massive in 2/3 of its length; embolic portion narrow, twisted, with a small tubercle distally.

Female. Unknown.

Distribution. The species is known only from the type locality in the Eastern Rhodope Mountains, Bulgaria.

Figures

FIGURES 1–6. Brachythele rhodopensis sp. n., holotype male. 1 habitus, dorsal; 2 carapace; 3 sternum; 4 spinnerets, ventral; 5 tibia I, ventral; 6 tibia I, lateral. Scale 2 mm.

FIGURES 7–12. Brachythele rhodopensis sp. n., holotype male, palp (7–9) and Brachythele langourovi, paratype, male, palp (10–12). 7, 10 prolateral; 8, 11 ventral; 9, 12 retrolateral. Scale 0.5 mm.

FIGURES 13–15. Brachythele rhodopensis sp. n., holotype male, palp. 13 prolateral; 14 ventral; 15 retrolateral. T—tegulum; E—embolus; K—embolic keel. Scale 0.5 mm.

FIGURES 26–27. Brachythele bentzieni, male palp. 26 ventral; 27 retrolateral. Scale 0.5 mm.