Pseudochthonius limettioides, Schimonsky, 2024

Schimonsky, Diego Monteiro Von, 2024, Two new cavernicolous species of Pseudochthonius Balzan, 1892 (Pseudoscorpiones, Chthoniidae) from Lagoa Santa karst, Minas Gerais, Brazil, Zootaxa 5433 (1), pp. 107-120 : 111-112

publication ID

https://doi.org/ 10.11646/zootaxa.5433.1.4

publication LSID

lsid:zoobank.org:pub:A8B8494C-4E8A-4D31-BE27-E370D6DF3C27

DOI

https://doi.org/10.5281/zenodo.10953717

persistent identifier

https://treatment.plazi.org/id/03ABC962-FFA9-FF97-FF2D-4E3DFB49A846

treatment provided by

Plazi

scientific name

Pseudochthonius limettioides
status

sp. nov.

Pseudochthonius limettioides sp. nov.

Fig. 3–4 View FIGURE 3 View FIGURE 4

Type material. Holotype: 1 ♂ ( LES22817 About LES ), BRAZIL: Minas Gerais, Cerrado province, Limeira massif karst area, Prudente de Morais , 01L cave; S19°26'32.5" W44° 6'24.3"; 04.iii.2019; Zampaulo, R. A.; Reis, A. S. leg. GoogleMaps Allotype: 1 ♀ ( LES22817 About LES ), together with the holotype .

Paratypes: 1 ♂ ( LES22817 About LES )together with the holotype ; 1 ♂ ( LES22813 About LES ), 40L cave; S19°26'24.9" W44°06'20.4"; 08.iii.2019; Zampaulo, R. A.; Reis, A. S. leg GoogleMaps ; 1 ♀ ( LES22798 About LES ), 51L cave; S19°26'23.5" W44°06'13.1"; 09.iii.2019; Zampaulo, R. A.; Reis, A. S. leg GoogleMaps ; 1 ♀ ( LES22805 About LES ), ES17 cave; S19°26'45.1" W44°06'10.2"; 08.iii.2019; Zampaulo, R. A.; Reis, A. S. leg GoogleMaps ; 1 ♀, 1 ♂ ( MZSP78847 View Materials ), 48L cave; S19º26'21.8'' W44º06'18.2''; 05.xii.2021; Zampaulo, R. A.; Reis, A. S. leg GoogleMaps ; 1 ♂ ( MZSP78848 View Materials ), 77L cave; S19º26'20'' W44º05'39''; 05.xii.2021; Zampaulo, R. A.; Reis, A. S. leg. GoogleMaps

Other studied material: 1 ♂, 1 ♀ ( LES22814 About LES ), ES05 cave; S19º26'29.6'' W44º06'24.6"; 01.iii.2019; Zampaulo, R. A.; Reis, A. S. leg GoogleMaps ; 2 ♀, 1 ♂ ( LES 22820 About LES ), ES13 cave; S19º26'29.44'' W44º06'25.6''; 06.iii.2019; Zampaulo, R. A.; Reis, A. S. leg GoogleMaps ; 1 ♀ ( LES22828 About LES ), ES03 cave; S19º26'29.44'' W44º06'25.6''; 01.iii.2019; Zampaulo, R. A.; Reis, A. S. leg GoogleMaps ; 1 ♀ ( ISLA 48243), 02L cave; S19º26'32.5'' W44º06'22.7''; 20.xi.2017; Bondezan, F. leg. GoogleMaps

Etymology. The epithet limettioides is in allusion to the tree known as Limeira in Portuguese which is the name of the karst massif where the new species occurs.

Diagnosis. Pseudochthonius limettioides sp. nov. can be identified by the absence of eyes or eyespots in males, one pair of eyespots in females, epistome prominent and dentate, appearing like a crown, cheliceral serrula exterior with 16 lamellae and interior with 14 lamellae and coxa II with some small protuberances appearing like a grater.

Description (adult male and female): Body: Specimens in 70% ethanol are yellowish-brown, in carapace, chelicera and pedipalps. The integument is weakly sclerotized and depigmented; tergites III–V with dark median mark ( Fig. 3 View FIGURE 3 ). Live specimen with most of body light yellow, and carapace, chelicera and pedipalps pale reddishbrown and a bit translucent. Male is smaller than female.

Carapace ( Fig.4A–B View FIGURE 4 ): epistome prominent, dentate, crown-like in appearance; eyeless (eyespot present in females); slightly constricted posteriorly; chaetotaxy 6:4:4:2:2 (18), one pair of preocular microsetae; 2 lyrifissures anteriorly, 2 medially and 2 posteriorly.

Chelicera ( Fig.4C–D View FIGURE 4 ): 3 lyrifissures; 5 setae on hand, with one seta (dt) on basal position of fixed finger and one seta (gl) close to basal position of movable finger, with two lateral microsetae (vb and vt), with two seta on central position of the hand (it and db); all setae acuminate; fixed finger with 7 teeth proximally reduced in size; movable finger with 6 teeth proximally reduced in size with subapical isolated tooth (di); serrula exterior with 14 blades; serrula interior with 16 blades; rallum with 7 pectinate blades. Movable finger of ♀ with a subapical small galea.

Pedipalp ( Figs.3E–G View FIGURE 3 ): 3.8 (♂)/3.4 (♀) × longer than patella; movable finger 1.8 (♂)/1.6 (♀) × longer than hand. Fixed chelal finger long and strongly sigmoid in distal half. Fixed finger with 34 distinctly separated acute teeth. Movable finger with 35 flattened and separated teeth. Trichobothria: ib and isb situated close to each other sub–medially in dorsal region of chelal hand; eb closer to esb than to ist, forming a straight oblique row at base of fixed chelal finger; ist three times closer to esb than to est (ratio ist-est/ist-esb = 3.0); et near tip of fixed finger; dx at end of the fixed finger; t closer to st and situated at same level as est, st closer to t, than sb to b.

Coxae ( Fig.3H View FIGURE 3 ): manducatory process distally acute, with 2 setae; pedipalpal coxae with 3 setae; coxa I with 5 setae and 2 coxal spines; coxa II with 5 setae and 4–5 coxal spines decreasing in size distally, and with some small protuberances appearing like a grater; coxa III with 7 setae; coxa IV with 8 setae; intercoxal tubercle absent. Coxal spines softly serrated, almost smooth.

Abdomen: chaetotaxy of tergites I–XI: 4: 4: 4: 4: 6: 6: 6: 6: 6: 5: 3. Chaetotaxy of sternites III–XI: (♂) 8: 3(14)3: 8: 8: 8: 8: 6: 5: 2 (♀) 12: 12: 8: 8: 8: 8: 6: 5: 2; anal cone with 0/2 setae. Genital area: ( Fig.3I View FIGURE 3 ): anterior genital operculum with 8(♂)/12(♀) marginal and discal setae, genital opening slit-like and triangular in males, with 7 marginal setae on each side; posterior operculum with 12 setae in females.

Legs: leg I: femur 5.8 (♂)/6.4 (♀) times longer than deep and 1.7 (♂)/1.5 (♀) longer than patella; patella 3.4 (♂)/4.2 (♀) times longer than deep; tibia 4.0 (♂)/4.5 (♀) times longer than deep; tarsus 9.6 (♂)/11.6 (♀) times longer than deep; tarsus 1.8 (♂)/1.9 (♀) times longer than tibia. Leg IV: femur + patella 2.3 (♂)/2.7 (♀) times longer than deep; tibia 4.1 (♂)/4.0 (♀) times longer than deep; basitarsus 2.8 (♂)/3.6 (♀) times longer than deep; telotarsus 10.3 (♂)/ 12.3(♀) times longer than deep.

Measurements and ratios: see Table 1 View TABLE 1 .

Remarks. The species resembles other Brazilian species of Pseudochthonius that lack eyes but have a pair of eyespots, P. ramalho and P. strinatii , but differs from them as follows: P. limettioides sp. nov. has rallum with 7 blades (8 in P. strinatii ), absence of microdenticles on fixed pedipalpal finger (2 present in P. ramalho ), and ratio ist-est/ist-esb = 3.0 (4.71 in P. ramalho ). Pseudochthonius limettioides sp. nov. differs from other cave-dwelling species of the genus by its ratio ist-est/ist-esb (0.68–0.85 in P. koinopoliteia , 1.0 in P. troglobius , 1.02 in P. diamachi , 1.22 in P. gracilimanus Mahnert, 2001 , 1.72 in P. galapagensis Beier, 1977 , 1.78–2.10 in P. biseriatus , 1.90 in P. lubueno 1.98 in P. ricardoi Mahnert, 2001 , 2.4 in P. arubensis , 2.46–2.77 in P. pali , 2.49 in P. olegario , 4.71 in P. ramalho and 2.0 in P. lundi sp. nov).

Distribution and habitat. The type locality of Pseudochthonius limettioides sp. nov. (01L Cave) is located in the Limeira Massif, near the dissolution dolmen, and is seasonally flooded by the rainwater that feeds it. Speleometrically, this cave has 175 m of horizontal projection, 3.5 m of unevenness, 416.9 m ² of surface area and 1,254.2 m ³ of volume. Morphologically it has a meandering pattern, with soil composed of clay sediment and chemical deposits represented by a variety of speleothems ( CANIE 2022, Robson de Almeida Zampaulo personal communication). Organic matter is introduced into the cave mainly by flood pulses, which allow the transport of leaf litter, root growth and even the capture of fish inside the cave. Almost entirely composed of aphotic zones with high isolation and humidity (Robson de Almeida Zampaulo personal communication). This new species occurs in other caves in the surroundings (02L, 25L 27L, 34L, 40L, 44L, 48L, 51L, 77L in the Limeira Massif and ES03, ES05, ES13, ES 17 in the Escrivânia massif,) with characteristics similar to those of the type locality. In addition to the troglomorphic pseudoscorpions, biological sampling of the cave fauna has recorded spiders, collembola.

TABLE 1. Measurements (in mm) of the holotype (male), allotype and paratypes of Pseudochthonius limettioides sp. nov.

  Holotype (male) Female allotype (paratypes)
Body 1.34 1.42 (1.04–1.45)
Carapace 0.29/0.26 [0.18] 0.32/0.26[0.20] (0.20–0.33/0.16–0.20)
Pedipalp femur 0.57/0.1 0.63/0.1 (0.46–0.67/0.1)
Pedipalp patella 0.22/0.11 0.27/0.12 (0.21–0.28/0.10–0.12)
Pedipalp chela 0.84/0.13 0.92/0.15 (0.72–0.93/0.12–0.15)
Pedipalp hand length 0.29 0.34 (0.22–0.36)
Pedipalp movable finger length 0.54 0.55 (0.45–0.56)
Chelicera length/width 0.34/0.16 0.42 (0.31–0.20
movable finger length 0.18 0.20
Leg I femur 0.29/0.05 0.32/0.05 (0.25–0.30/0.05)
Leg I patella 0.17/0.05 0.21/0.05 (0.13–0.17/0.04–0.05)
Leg I tibia 0.16/0.04 0.18/0.04 (0.16–0.20/0.04)
Leg I tarsus 0.29/0.03 0.35/0.03 (0.27–0.34/0.03)
Leg IV femur+patella 0.45/0.19 0.47/0.17 (0.35–0.51/0.17–0.19)
Leg IV tibia 0.29/0.07 0.29/0.07 (0.22–0.31/0.06–0.07)
Leg IV basitarsus 0.14/0.05 0.18/0.05 (0.13–0.19/0.04–0.05)
Leg IV tarsus 0.31/0.03 0.37/0.03 (0.30–0.35/0.03)
R

Departamento de Geologia, Universidad de Chile

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