Pachychernes florezi, Marimon & Villarreal-Blanco & Romero-Ortiz & Gutierrez, 2021

Marimon, Karla, Villarreal-Blanco, Eduardo, Romero-Ortiz, Catalina & Gutierrez, Luis C., 2021, A new species and new records of Pachychernes Beier, 1932 from Colombia (Pseudoscorpiones, Chernetidae), Zootaxa 4999 (4), pp. 363-376 : 365-369

Pachychernes florezi sp. n.

Figs. 1A–D , 2A–D , 3A–G , 7A

Type material. Male holotype: COLOMBIA, Bolívar , Municipio de San Jacinto , Vereda La Flecha, Finca Amanecer Gaitero (9°51’9.74”N; 75°10’32.32”W), 250 masl. 11–12.IX.2019, K. Marimon & E. Villarreal leg. (ICN-Aps- 833) . Paratypes: four males and six females (IAvH-I-4087 [5♀]; IAvH-I-4088 [4♂]; ICN-Aps-834 [1♀]) with the same data as the holotype .

Etymology. The specific epithet is a patronym in honour of Dr. Eduardo Florez, for his many contributions to arachnology in Colombia. Because he was a pioneer, he has been given the title of the father of arachnology in Colombia.

Differential diagnosis. Pachychernes florezi sp. n. is similar to P. zehorum , P. attenuatus , P. tamaulipensis , P. corticalis , P. shelfordi and P. baileyi by having a sexual dimorphism on the first pair of legs in males. However, it differs from P. zehorum by the absence of a depression on the dorsal face of tarsus I in males. From P. attenuatus by having thicker pedipalps, with a femoral ratio of 1.83–2.48 vs 3.86–4.42 and a ratio of the patella of 1.85–2.14 vs 3.16–3.69 in P. florezi sp. n. and P. attenuatus , respectively. From P. tamaulipensis by the presence of external accessory teeth on the chelal fingers. From P. corticalis and P. shelfordi by having a spermatheca composed of a long and curved duct with terminally expanded ends or globose sacs located at the same level, while both P. corticalis and P. shelfordi have shorter ducts with sacs ending one above the other. From P. baileyi by its body length, being P. florezi sp. n. smaller 2.57–3.69 vs 4.50–4.80 and the ratios of leg IV segments, such as the femur, 1.13–1.57 in P. florezi sp. n. vs 2.30–2.60 in P. baileyi .

Besides, Pachychernes florezi sp. n. differs from P. subrobustus by the lack of sexual dimorphism on the chelal hand of males; from P. subgracilis by having broader chelal hands (1.40–1.62 vs 3.50); from P. gracilis and P. robustus by the short length of that segment, with a ratio of 0.78–0.94 × longer than the movable finger, while that of P. gracilis and P. robustus is over 1.50 and 1.60 × longer than the movable finger, respectively.

Description (adults): Colour: carapace brown with a lighter tone towards the posterior margin. Tergites light brown while pedipalps dark reddish-brown. Legs light yellow-brown toned.

Carapace: heavily granulated with a subrectangular shape; 1.20–1.33 (♂) 0.84–1.21 (♀) × longer than broad, with two eye spots; anterior margin with 6 setae (♂), posterior margin with 10 setae (♂) ( Fig. 1 ).

Chelicera: 1.50–1.75 (♂), 1.63–1.92 (♀) × longer than broad; with 5 setae on hand and 1 distal seta on mov- able finger, all setae acuminate; galea with 6 rami (♀) 3 rami (♂); rallum with 3 blades, anterior blade with several ramifications while others smooth; serrula exterior with 21 blades (♂, ♀); lamina exterior present ( Fig. 3 ).

Pedipalp: robust with trochanter, femur and patella granulated, hand slightly granulated with several denticulated setae and chelal fingers smooth; trochanter 1.12–1.58 (♂), 1.13–1.21 (♀), femur 1.91–2.48 (♂), 1.83–2.24 (♀), patella 1.85–2.14 (♂), 1.84–2.10 (♀), chela (with pedicel) 3.00–3.38 (♂), 2.67–3.17 (♀), chela (without pedicel) 2.80–3.15 (♂), 2.46–2.98 (♀), hand 1.54–1.70 (♂), 1.40–1.62 (♀) × longer than broad, movable finger 0.78–0.87 (♂), 0.73–0.94 (♀) × longer than hand. All marginal teeth rounded except the terminal ones, which are pointed. External accessory teeth present on both fingers, with 6 (♂), 7 (♀) on the movable finger and 9 (♂), 11 (♀) on the fixed finger. Fixed chelal finger with 8 trichobothria, movable chelal finger with 4 trichobothria: eb, esb, est and et, eb and esb situated basally, est subbasally and much closer to esb than et, which is located subterminally; ib and ist basally located with ist close to eb and esb, it located subdistally on the medial half of finger, and isb located in a medial position and approximately equal length from it and ib; b, sb and st grouped basally with b and sb much closer to each other than to st, t located midway, closer to st than tip of finger. Venom apparatus present only in movable chelal finger with nodus ramosus slightly proximal to t ( Figs. 2 , 3 ).

Coxal region: maxillae smooth except for the antero-lateral region, coxae smooth, manducatory process triangular in shape with 2 (♂) 1 (♀) apical setae and 3 (♂) 1 (♀) internal suboral setae with 33 other remaining setae. Maxillary lyrifissure rounded and placed submedially. Chaetotaxy of coxae I–IV, ♂: 11: 11: 16: 31; ♀: 12: 11: 13: 40.

Legs: leg I sexually dimorphic, with males having a tibia with large number of setae and a tarsus without a concavity. Femur + patella of leg IV 2.41–2.60 (♂), 2.15–2.61 (♀) × longer than broad, as well as tibia and tarsus 3.24–3.67 (♂), 3.11–3.53 (♀) and 4.00–4.20 (♂), 3.27–4.67 (♀) × longer than broad, respectively. Tarsi III and IV with tactile seta, located subbasally, TS= 0.15 in both males and females. Claws and arolium are equal in length ( Figs. 2 , 3 ).

Abdomen: tergites I–X and sternites III–X with a clear medial suture line. Tergal chaetotaxy: ♂, 1: 13: 9: 12: 14: 13: 14: 13: 14: 12: 4; ♀, 11: 11: 12: 13: 17: 15: 18: 17: 15: 17: 12: 2, all setae clavate, leaf-like. Sternal chaeto- taxy: ♂, 49: (3) 15 (2): (1) 7 (1): 16: 17: 18: 18: 17: 18: 17: 4; ♀, 27: (1)11(1): (1)9(1): 16: 19: 18: 19: 20: 21: 14:2. Spiracle with helix. Pleural membrane striated and without setae.

Genitalia: spermatheca slightly H-shaped, with four lobes, the anterior ones, oval in shape while the posterior ones have a tubular form with several cribriform plates along the ducts that end on a sac placed right behind the first lobes ( Fig. 7A ). Male genital plate with 49 setae on the anterior operculum and 15 on the posterior operculum.

Dimensions: holotype male, followed by 4 male paratypes in parentheses: Body length 2.65 (2.65–3.18). Carapace 0.97/0.76 (0.84–0.97/0.70–0.76). Chelicera 0.24/0.14 (0.24–0.28/0.15–0.16), movable finger length 0.23 (0.22–0.25). Pedipalps: trochanter 0.37/0.33 (0.41–0.44/0.26–0.34), femur 0.67/0.35 (0.72–0.83/0.29–0.37), patella 0.84/0.40 (0.73–0.92/0.35–0.43), chela (with pedicel) 1.51/0.50 (1.35–1.51/0.40–0.50), chela (without pedicel) 1.40 (1.26–1.42), hand (without pedicel) length 0.77 (0.68–0.80), movable finger length 0.64 (0.57–0.65). Leg IV: femur 0.30/0.24 (0.27–0.31/0.19–0.24), patella 0.74/0.34 (0.59–0.74/0.28–0.34), tibia 0.63/0.18 (0.55–0.63/0.15–0.18) tarsus 0.44/0.11 (0.37–0.44/0.09–0.11).

Dimensions: allotype female, followed by 5 female paratypes in parentheses: Body length 3.20 (2.57–3.69). Carapace 0.87/1.03 (0.94–1.06/0.78–0.93). Chelicera 0.29/0.16 (0.22–0.26/0.12–0.16), movable finger length 0.26 (0.20–0.24). Pedipalp: trochanter 0.41/0.34 (0.35–0.43/0.29–0.36), femur 0.80/0.37 (0.66–0.80/0.33–0.40), patella 0.88/0.42 (0.70–0.89/0.38–0.55), chela (with pedicel) 1.5/0.51 (1.39–1.65/0.45–0.57), chela (without pedicel) 1.38 (1.28–1.55), hand (without pedicel) length 0.80 (0.70–0.84), movable finger length 0.63 (0.58–0.72). Leg IV: femur 0.37/0.29 (0.29–0.37/0.23–0.29), patella 0.74/0.38 (0.67–0.79/0.28–0.39), tibia 0.62/0.19 (0.56–0.68/0.17–0.21), tarsus 0.35/0.10 (0.36–0.42/0.09–0.11).

Distribution and habitat. This species is recorded from the Montes de María in the Caribbean region of Colombia. This region supports most of the remaining Tropical Dry Forest in the country. The specimens were found under tree bark, in a forest fragment at the edge of a stream, cohabiting with specimens of Paratemnoides nidificator (Balzan, 1888) . Sampling is needed to determine the actual range and habitat preference of the species ( Figs. 8 , 9 ).

Figures

FIGURE 1. Pachychernes florezi sp. n., male holotype (ICN-Aps-833). A–B. Habitus. A. Dorsal view. B. Ventral view. Allotype female (ICN-Aps-834). C–D. Habitus. C. Dorsal view. D. Ventral view. Scale lines A–D = 1mm

FIGURE 2. Pachychernes florezi sp. n.; male holotype. A. Left pedipalp. B. Left chela, lateral view. C. Left leg I. D. Left leg IV. Scale bars: A–B, F–G: 0.3mm. C: 0.1 mm; D–E: 0.05 mm.

FIGURE 3 Pachychernes florezi sp. n., female allotype. A. Left pedipalp. B. Left chela, lateral view. C. Left chelicera. D. Rallum. E. Galea. F. left leg IV. G. left leg I. Scale bars: A–B: 0.3 mm; C, G: 0.1 mm; D–E: 0.05 mm. F: 0.5 mm.

FIGURE 7. Schematic representation. of spermathecae. A. Pachychernes florezi sp. n. B. Pachychernes zehorum.

FIGURE 8. A–B. Type locality of Pachychernes florezi sp. n. and habitat of P. zehorum. San Jacinto, Bolívar.

FIGURE 9. Known distribution of extant species of Pachychernes.