Mexentypesa hidalguensis, Salinas-Velasco & Valdez-Mondragón & Villegas, 2024

Salinas-Velasco, Héctor Vicente, Valdez-Mondragón, Alejandro & Villegas, Julián Bueno-, 2024, A new species of the spider genus Mexentypesa Raven (Araneae: Nemesiidae) from Hidalgo, Mexico and taxonomic comments on M. chiapas Raven, Zootaxa 5453 (2), pp. 233-244 : 235-241

Mexentypesa hidalguensis sp. nov.

Figures 1–27

Type material. MEXICO: Hidalgo: 1 ♂ holotype (CNAN-T01589) , 1 ♂, 1 ♀ paratypes (CNAN-T01590, CNANT01591) from La Mojonera (lat 20.626111°, lon -98.618611°, 2040 m), Municipio Zacualtipán de Ángeles , 27.vii.2021, H. V. Salinas-Velasco Col. Daytime collection .

Etymology. The specific epithet is a noun in apposition, in reference to the state where the type locality is found: Hidalgo, in central Mexico.

Diagnosis. Males of M. hidalguensis sp. nov. are easily distinguished from M. chiapas by having a shorter embolus ( Figs 8–12 ), larger in M. chiapas , reaching the level of the joint patella-tibia of the palp ( Figs 32, 33, 34, 36 ). Massive ventral and prolateral spines on the palpal tibiae are fewer in the new species ( Figs 9, 10, 12 ) than in M. chiapas , which also have one located basally to the tibia ( Figs 32, 34, 35 ). Each endites in the new species has a patch of 4–6 small cuspules on proximal inner part ( Fig. 7 ), whereas a patch of 11–13 small cuspules on each endite in M. chiapas ( Fig. 43 ). The new species has a total of 10 spines on tibia I: 2 retrolateral, 7 ventral, and 1 ventralretrolateral ( Fig. 17 ), whereas M. chiapas has only 7 spines and a massive spine on tibia I ( Fig. 37 ). Carapace and opisthosomal coloration patterns in the new species ( Figs 1, 2 ) differ from M. chiapas ( Figs 28, 30 ). Females also differ in seminal receptacles; in M. hidalguensis sp. nov., seminal receptacles are widely separated from each other ( Fig. 25 ), whereas in M. chiapas they are close together to each other ( Fig. 44 ). Females of the new species further differ from M. chiapas by the presence of rastellum on the chelicerae and the absence of granules on them. In addition, females of the new species has a well-defined scopula on all tarsi, especially on the pedipalp.

Description. Male (holotype) (CNAN-T01589): Measurements: Total length (prosoma + opisthosoma) 9.50. Carapace 3.70 long, 3.30 wide. Clypeus length 0.20. Diameter of AME 0.16, ALE 0.20, PME 0.16, PLE 0.18. Labium: LBl 0.25, LBw 0.63. Sternum: STRl 2.10, STRw 1.70. Leg lengths: I femur 2.00/ patella 1.50/ tibia 1.50/ metatarsus 1.10/ tarsus 1.03/ total 7.13; II- 2.00/ 1.50/ 1.50/ 1.10/ 1.10/ 7.20; III- 4.03/ 1.06/ 1.10/ 1.50/ 1.02/ 8.71; IV- 2.51/ 1.30/ 1.50/ 2.70/ 1.50/ 9.51. Leg formula: 4-3-2-1. Prosoma: Carapace longer than wide, with a setose surface, pyriform-shaped, dark brown coloration ( Figs 1, 2 ). Ocular region over a tubercle ( Fig. 6 ). Foveal groove slightly deep ( Fig. 2 ). AER slightly procurved, PER slightly recurved ( Fig. 5 ). Largest ALE, smallest AME ( Fig. 5 ). Sternum longer than wide, nonagonal-shaped, reddish brown, more setose towards posterior margin, without sigilla ( Fig. 4 ). Labium wider than long, reddish brown, with long setae anteriorly, without cuspules ( Figs 4 , 7 ). Endites long with only few setae, with a patch of 4–7 small cuspules on proximal inner part on each endite ( Fig. 7 ). Endites with a prolateral conical apophysis. Chelicerae: Promargin furrow with 6 teeth, retromargin furrow with single row of very long setae. Rastellum consists of numerous long, thick setae, but without stout spines (arrow, Fig. 6 ). Opisthosoma: Longer than wide, setose, dark brown, with irregular light brown pattern dorsally; ventrally with brown undefined spots, close to spinnerets and lungs ( Fig. 3 ). Spinnerets dark brown. PMS small and rounded apically, single segment, with spigots. PLS long and conical apically: basal segment length = median segment> distal segment. Legs: Well-developed scopulae on all legs ( Fig. 21 ). Tarsi with trichobothria: Tarsi I–IV: slightly staggered dorsal row with 12 trichobothria each, distal ones becoming larger; Legs spination pattern: Tibiae I: v(2+2+2+2) (one of the last spines ventral-retrolaterally is massive) (Figs 13,14,17), p(2+2) (larger than v); tibiae II: v(2+2+2+2), p(2); metatarsi I: v(2); metatarsi II: v(2+2+2), p(2+2). Leg III and IV spination pattern is illustrated in Figure 14 . Pedipalps: Articles dark brown, slender, femora and tibiae with long setae ventrally and dorsally ( Figs 8, 10 ). Patellae with three distal ventral-prolateral spines. Tibiae with two massive ventral and one prolateral spines ( Figs 9, 12 ). Cymbium with six dorsoapical spines ( Figs 10, 12 ). Bulb pyriform, turned ventrally toward a concavity on ventral part of tibiae ( Figs 10–12 ). Embolus long, slender, and sigmoidal, almost the same length as tibiae ( Figs 8–12 ).

Description. Female (CNAN-T01591). Similar to the male, differences: Measurements: Total length (prosoma + opisthosoma) 13.00. Carapace 6.50 long, 4.50 wide. Clypeus length 0.30. Diameter of AME 0.19, ALE 0.23, PME 0.19, PLE 0.21. Labium: LBl 0.28, LBw 0.66. Sternum: STRl 2.20, STRw 2.00. Leg lengths: I femur 2.70/ patella 1.50/ tibia 1.60/ metatarsus 1.50/ tarsus 1.50/ total 8.80; II- 2.50/ 1.50/ 1.60/ 1.50/ 1.00/ 8.10; III- 2.00/ 1.50/ 1.50/ 2.00/ 1.25/ 8.25; IV- 2.50/ 1.50/ 2.00/ 2.50/ 1.50/ 10.00. Leg formula: 4-1-3-2. Prosoma: Carapace longer than wide, with surface smooth, setose, pyriform-shaped, dark brown coloration ( Fig. 22 ). Ocular region slightly elevated. Foveal groove slightly deep. AER slightly procurved, PER slightly recurved. Largest ALE, smallest AME. Sternum longer than wide, nonagonal-shaped, reddish brown, more setose towards posterior margin, without sigilla. Labium wider than long, reddish brown, with long setae anteriorly, without cuspules. Endites long setose, with a patch of 4–6 small cuspules on proximal inner part on each endite ( Fig. 23 ). Chelicerae: Promargin furrow with 6 teeth, retromargin furrow with single row of very long setae. Rastellum consists of numerous long, thick setae, but without stout spines. Opisthosoma: Longer than wide, setose, dark brown, without irregular light brown pattern dorsally; ventrally dark brown without any pattern ( Figs 22, 24 ). Spinnerets dark brown. PMS small and rounded apically, single segment, with spigots. PLS long and conical apically: basal segment length> median segment <distal segment ( Fig. 24 ). Legs: Light tarsal scopulae on all legs. Tarsi with trichobothria: Tarsi I–IV: slightly staggered dorsal row with 12 trichobothria each, distal ones becoming larger; Leg spination patterns: Tibiae I: v(2+2); tibiae II: v (2+2+2), p(2+2+2); tibiae III and IV: v(3+3+3), p(2+2+2); metatarsi I and II: v(2+1); metatarsi III and IV: v(2+2+2), p(2+2); all tarsi: without spines. Pedipalps: Articles stouter and darker coloration than in male, setose, with long and dense scopulae on tarsi. Tarsi with two claws; spination pattern: v(2+1). Genital area: Flat, halfmoonshaped, setose, dark brown color. Two thin seminal receptacles, poorly sclerotized ( Fig. 25 ).

Variation. Females are darker than males. Males (N = 2): Cl 3.50–3.70, 3.60±0.10; Cw 3.12–3.3, 3.21±0.09; STRl 1.98–2.10, 2.04±0.60; STRw 1.60–1.70, 1.65±0.05; PTl 1.29–1.37, 1.33±0.08; PTw 0.47–0.50, 0.48±0.20; Tibiae I (length): 1.78–1.93, 1.85±0.80. No differences were found in the position of the spines on tibia I, the palp tibia spines, or the spines on the Cy between both observed individuals ( Figs 13, 14 ).

Natural History. Holotype and paratypes were collected in a cloud forest near La Mojonera, Hidalgo, Mexico ( Fig. 26, 27 ). Manual collection is likely the most effective method. No specimens have been observed outside of decaying logs (saproxylic habits) where they construct their burrows, which consist of a silk-lined sac with multiple layers, featuring only a single entrance that is slightly smaller than the extended spider. These egg-sacs are typically found at a depth ranging of 5–15 cm (measured from the bark towards the interior of the log). These spiders can be collected throughout the year, with a higher likelihood of abundance between the months of August to November .

Distribution. MEXICO: Hidalgo ( Fig. 45 ).

Figures

FIGURE 45. Known records of Mexentypesa hidalguensis sp. nov. (red circle) and M. chiapas (red diamonds).

FIGURES 1–4. Mexentypesa hidalguensis sp. nov. Male holotype: 1, 3, Habitus, dorsal and ventral views, respectively. 2, Carapace, dorsal view. 4, Prosoma, ventral view showing coxae, sternum, labium, and endites.

FIGURES 5–12. Mexentypesa hidalguensis sp. nov. Male holotype: 5, Ocular region. 6, Chelicerae, lateral view. 7, Endites, ventral view; showing detail of the cuspules. 8–9, Right palp, retrolateral and prolateral views, respectively. 10–12, Right palp, retrolateral-apical, ventral-apical, and prolateral-apical views, respectively.

FIGURES 13–21. Mexentypesa hidalguensis sp. nov. Male holotype: 13, Holotype tibia I, proventral view. 14, Paratype proventral view. 15–16, Left leg I, retrolateral and prolateral views, respectively. 17–18, Spination pattern on tibia I, III, and IV (arrows indicate the spines). 19, Left leg I, dorsal view. 20, Metatarsus I, showing the small finger-shaped projection on retrolateral-ventral part. 21, Tarsus I, retrolateral view.

FIGURES 22–25. Mexentypesa hidalguensis sp. nov. Female: 22, 24, Habitus, dorsal and ventral views, respectively. 23, Endites showing the cuspules. 25, Seminal receptacles, dorsal view.

FIGURES 26–27. 26, Live female of Mexentypesa hidalguensis sp. nov. 27, Cloud forest in La Mojonera, Hidalgo, Mexico, where the type specimens were collected (photos by Héctor Vicente Salinas-Velasco).

FIGURES 32–36. Mexentypesa chiapas Raven, 1987. Male: 32–33, Left palp, prolateral and retrolateral views, respectively. 34, Left palp, ventral view. 35, Left palp, prolateral-apical view (arrow indicates apical spines on cymbium). 36, Detail of the bulb and embolus, ventral view. Scale bars 0.5 mm (35), 1 mm (32–34, 36). Modified of Valdez-Mondragón and Cortez-Roldán (2016).

FIGURES 37–44. Mexentypesa chiapas Raven, 1987. Male: 37, Tibia I, retrolateral view. 38, Tarsus I, retrolateral view. 39, Metatarsus and tarsus I, dorsal view (arrow indicates the small finger-shaped projection on retrolateral-ventral part of metatarsus). 40, Metatarsus I, retrolateral view (ditto). 41, Detail of the small finger-shaped projection on retrolateral-ventral part of metatarsus I. 42, Spination pattern on legs III and IV. 43, Endites, ventral view; detail of the cuspules. Female: 44, Seminal receptacles, dorsal view. Scale bars 0.2 mm (41), 0.5 mm (38, 40, 43), 1 mm (37, 39), 2 mm (42). Modified of Valdez- Mondragón and Cortez-Roldán (2016) (Figs 37–43), Modified of Raven (1987) (Fig 44).

FIGURES 28–31. Mexentypesa chiapas Raven, 1987. Male: 28–29, Habitus, dorsal and ventral views, respectively. 30, Carapace, dorsal view. 31, Prosoma, ventral view showing coxae, sternum, labium, and endites (arrow indicates cuspules). Scale bars 0.5 mm (28, 29), 0.2 mm (30, 31). Modified of Valdez-Mondragón and Cortez-Roldán (2016).