Pseudochthonius koinopoliteia Prado & Ferreira 2023, sp. nov.
Creators: name: Prado, Guilherme C.
name: Ferreira, Rodrigo L.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Pseudoscorpiones
Chthoniidae
Pseudochthonius
Pseudochthonius koinopoliteia

description: Pseudochthonius koinopoliteia sp. nov.
Material examined. Holotype male (ISLA 100996), preserved in ethanol: Brazil, Carinhanha, Bahia, Gruna da Água Clara Cave (13º48’4.26”S, 43º57’6.24”W), 11 October 2017, leg. R. L Ferreira. Allotype female (ISLA 100997), preserved in ethanol: Brazil, Carinhanha, Bahia, Pedro Cassiano Cave (13º47’52.80”S, 43º54’50.40”W), 14 September 2021, leg. R. L Ferreira. Paratype female (ISLA 103872), preserved in ethanol: same local and coordinates as holotype, 3 September 2022, leg. R. L Ferreira.
Etymology. Koinopoliteía (from Greek “κοινοπολιτεία”) can be translated as commonwealth. As previously mentioned, Brazilian caves are a public good, with no possibility of ownership by individuals or entities. This noun should be treated as a noun in apposition.
Diagnosis. Differing from the other members of the genus by the following combination of characters: Absence of eyes or eyespots; carapace rectangular with almost no posterior constriction; ist–est/ist–esb trichobothria ratio of 0.68 (0.73–0.85); chelal fixed finger with 38 acute teeth with heterodonty starting from the 10 th proximal tooth, chelal movable finger with 38 acute and well-defined teeth; cheliceral fixed finger with 7 teeth, exhibiting a constriction between the second and 5 th proximal ones, movable finger of the chelicera with 8 (13) teeth, the second and third ones constricted, with a distal isolated tooth; presence of two setae on the first and second tergites; trichobothrium et proximad to dx and distad to it; body length of 1.69 (1.71–1.95) mm; chela 7.2 to 7.7 times as long as broad.
Description (Figs 6D, 8C). Body pale yellowish, very translucent; chelicerae slightly orange, abdomen beige. Some parts of the body scaly. Vestitural setae thin and anteriorly projected on prosoma and posteriorly projected on opisthosoma.
Carapace (Fig. 5D). 1.18 (1.12–1.21) times longer than broad, posteriorly slightly constricted showing a difference between ocular width and posterior width of 0.03 (0.06) mm (Fig. 5D); anterior margin partially serrated; no eyes or eyespots; epistome small and strongly dentate and serrated (ranging to seta ame); posterior margin of carapace smooth; chaetotaxy 4+2: 4: 4: 2: 2 (18).
Chelicera (Figs 2D–E, 5H). Hand with 5 setae; movable finger with 1 subdistal seta; galea present as a tubercle; fixed finger with 7 acute teeth highly constricted between 2 nd and 5 th (including a small slightly distal one); movable finger with 9(13) acute teeth (including a small distal one) with 2 nd and 3 rd teeth highly constricted (Figs 2D, 10H); rallum with 7 blades; serrula exterior with 15 blades, serrula interior with 9 blades.
Tergites. Not divided; surface smooth; chaetotaxy uniseriate, I–XI 2: 2: 4: 4: 4: 6: 6: 6: 6: 2: 2. Anal operculum without dorsal setae. Pleural membranes slightly striate.
Coxae (Figs 5A, F). Manducatory process with two apical setae; rest of palp coxae with 3 setae arranged in a triangle; delicate lamellae outlined by 10(11) small spines. Pedal (Figs 5A, F): coxal spines plumose, arranged in a single transverse row in coxae I (5–6) and II (4–5) (Fig. 5F), chaetotaxy: I 4+1, II 5– 6, III 8, IV 7–8 (9); intercoxal tubercle absent.
Genital operculum of female: 8 setae distributed in three transversal rows: 2: 4: 2, genital opening not bifurcated, 3 rd tergite with 16 linear setae.
Genital operculum of male (Fig. 5G): Anterior genital operculum with 8 discal setae, 6 valvular genital setae and 4 setae along the sternite, with 2 microlateral setae on each side.
Sternites: chaetotaxy IV‒XI: 10+ 4–6m: 8+ 2m: 8+ 2m: 9 (10): 8 (9): 6: 2(3: 4 + 2 sensory setae. Anal operculum with 2 ventral setae.
Palp (Figs 5C, I). Trochanter 1.66 (1.27–1.65) times longer than wide, femur 6.76 (6.63–6.85) times longer than wide, patella 2.16 (2.13–2.26) times longer than wide. Femoral chaetotaxy 5: 5 (6): 3 (5): 6: 2. Trichobothrial pattern: ib and isb located at the half portion of the hand, adjacent to each other, slightly dislocated to the paraxial face of the chela, eb proximad to esb, it proximad to est, et distad from it and proximad to dx; ist closer to est than esb (ratio distance ist-est/ist-esb = 0.68 (0.73–0.85). Fixed finger slightly sigmoid; movable finger slightly curved (Fig. 5I). Chelal fixed finger with 38 (39) acute, triangular, and widely spaced teeth, with heterodonty starting proximally from the 10 th teeth. Movable finger with 38 acute, triangular, and widely spaced teeth, alternated in size.
Leg IV (Fig. 5B). Arolia almost with the same length as claws; a soft hump near end of telotarsus.
Measurements (length/width or depth in mm and ratios in parenthesis calculated by using three significant digits): Male holotype (female paratypes in brackets). Body length 1.69 [1.71–1.95]. Carapace 0.46/0.39 (1.2) [0.49–0.50/0.40–0.42 (1.2)]. Palps: trochanter 0.21/0.13 (1.7) [0.17–0.23/0.13–0.14 (1.3–1.6)], femur 0.74/0.11 (6.8) [0.78–0.82/0.11–0.12 (6.8–6.9)], patella 0.28/0.13 (2.2) [0.28–0.31/0.13–0.15 (2.3)], chela 1.04/0.15 (7.2) [1.04–1.16/0.14–0.17 (7.6–7.7)], movable finger length 0.66 [0.70–0.71]. Leg I: trochanter 0.14/0.11 (1.2) [0.13– 0.15/0.11–0.13 (1.2)], femur 0.43/0.07 (6.1) [0.46/0.07–0.08 (6.2–6.5)], patella 0.22/0.06 (4.0) [0.23–0.24/0.06 (4.0–4.1)], femur/patella 1.95 [1.93–2.00], tibia 0.23/0.05 (4.8) [0.23–0.24/0.05 (4.8–4.9)], tarsus 0.45/0.05 (10.0) [0.48–0.49/0.04–0.05 (9.8–11.6)]. Leg IV: Trochanter: 0.27/0.14 (1.9) [0.17–0.24/0.13 (1.3–1.8)], femur + patella 0.72/0.21 (3.3) [0.73–0.75/0.21–0.23 (3.5)], tibia 0.45/0.08 (5.4) [0.45–0.48/0.07–0.09 (5.5–6.1)], basitarsus 0.25/0.07 (3.4) [0.25–0.26/0.06–0.07 (3.9–4.1)], telotarsus 0.54/0.04 (13.8) [0.58/–0.04 (16.5)].
Ecological Remarks. Specimens of Pseudochthonius koinopoliteia sp. nov. were found in two caves: Gruna da Água Clara cave(Figs6A–C)and Gruna do Pedro Cassiano cave(Figs7A–D), both located in Carinhanha municipality, southwestern Bahia state, Brazil. The Gruna da Água Clara cave has 13.880 meters of horizontal projection and belongs to a set of functionally interconnected caves known as the Água Clara cave system (ACCS). This system has approximately 24 km of extension, composed of four limestone caves traversed by an intermittent stream, active during the austral summer (October to March) (Souza-Silva et al. 2021). On the other hand, the Gruna do Pedro Cassiano cave presents 2.660 meters of horizontal projection and does not belong to the ACCS, even located near the system (about 4 km in straight line).
Although Gruna do Pedro Cassiano cave receives local visitors sporadically, the water flow trespassing the cave during the rainy periods (Figs 7C–D) seasonally “erases” eventual impacts caused by the visitors (such as trampling on cave sediments). Furthermore, local visitors do not reach the deepest regions of the cave–where the only specimen was found–since visitors tend to stay closer to the entrance. On the other hand, only speleologists visit the Gruna da Água Clara cave during technical/scientific expeditions, which seldom occurs. Such activities apparently do not represent a threat to the species. Most of the original forests have been removed and replaced by pastures or other monocultures, severely altering the surrounding external environment (Fig. 7A).
description: Published as part of Prado, Guilherme C. & Ferreira, Rodrigo L., 2023, Three new troglobitic species of Pseudochthonius Balzan, 1892 (Pseudoscorpiones, Chthoniidae) from northeastern Brazil, pp. 92-110 in Zootaxa 5249 (1) on pages 98-100, DOI: 10.11646/zootaxa.5249.1.5, http://zenodo.org/record/7685373