Chthonius (Chthonius) hungaricus Mahnert 1981
Creators: name: Gardini, Giulio
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Pseudoscorpiones
Chthoniidae
Chthonius
Chthonius hungaricus

description: Chthonius (C.) hungaricus Mahnert, 1981
(Figs 34–41, 90)
Chthonius (Chthonius) diophthalmus (not Daday, 1889): Beier 1939a: 2, fig. 1 (misidentification, in part: see C. heterodactylus).
Chthonius (C.) hungaricus Mahnert 1981: 279, figs 1–5; Christophoryová et al. 2011a: 2, figs 1A–D.
Type locality: Hungary, Hajdú-Bihar, Hortobágyi Nemzeti Park, Újszentmargita (47°43′ N 21°06′ E).
Distribution. Hungary, Romania, Slovakia.
Diagnosis (♂♀). An eyed, epigean Chthonius (Chthonius) from the Carpathians that differs from other species of the heterodactylus group in the following combination of characters: carapace with epistome, usual chaetotaxy mm 4mm:6:4:2:2 (22) or mm 4mm:6:4:2:m 2m (24); chaetotaxy tergites I–IV: 4:4:4:4; genital opening of males flanked by aligned setae on each side; fixed chelal finger with 34–50 teeth with dental canals (8–14 distal teeth contiguous, pointed or apically rounded, slightly inclined backwards; 9–15 large, sharp, reclined and spaced teeth without intercalary microdenticles; 9–21 proximal teeth low, contiguous and rounded, reduced in size towards finger base); fixed chelal finger with simple, not enlarged, distal paraxial seta; movable chelal finger with 28–36 reclined, usually low, teeth with dental canals, increasingly reduced towards the finger base, reaching back between sb and b; coupled sensilla pc of movable chelal finger between trichobothria st and sb; chela length 0.63–0.81 (♂) or 0.68–0.77 (♀), movable finger length 0.43–0.53 (♂) or 0.46–0.52 (♀).
Material examined. ROMANIA — Bihor: 2 T, “ Roumanie: Bihor, Vascàu / 15.VII.1938 —R. Leruth (575) Steinen im Mischwald / 1350 m. M. Beier det., 1939 / C. (Chthonius) diophthalmus Daday / 2 juv. ” “ Roumanie: Chiscàu. alt. 1350 m. / N° 575 (pierres enfoncées) / 15.VII.1938 / R. Leruth” (IRSNB); 1 ♂, 1 ♀, “ Roumanie: Bihor / 24.VIII.1938 —R. Leruth (R.99) Pesterea de la Searducel / 350 m. M. Beier det., 1939 / C. (Chtonius) [sic!] diophthalmus Daday / 1 ♂, 2 ♀” “ Roumanie: Vârciorog. alt. 350 m. R99 / (sur du bois) / 24.VIII.1938 / R. Leruth” (together with 2 ♀ of C. heterodactylus) (IRSNB). Cluj: 1 ♀, “ Roumanie: Turda—Jara / 7.VI.1938 —R. Leruth (552) Steinen im Buchenwald / 650 m M. Beier det., 1939: / C. (Chthonius) diophthalmus Daday / 3 ♂, 1 ♀” “ Roumanie: Sàcel, alt. 650 m. N° 552 / (pierres enfoncées) / 7.VI.1938 / R. Leruth” (together with 4 ♂, 2 D of C. heterodactylus) (IRSNB); 6 ♂, 1 ♀, 3 T, 1 D, “ Roumanie: Turda—Jara / 7.VI.1938 —R. Leruth (553bis) Laub und Humus / M. Beier det., 1939 / C. (Chthonius) diophthalmus Daday / ♂♂ ♀♀” “ Roumanie: Sàchel—alt. 600 m. N° 553bis / (feuilles mortes, humus) / 7.VI.1938 / R. Leruth” (together with 1 ♂, 1 T of Mundochthonius carpaticus Rafalski, 1948) (IRSNB); 2 ♂, “ Roumanie: Câmpeni, / Turda, 19.VII.1938. R. Leruth R66A. Hoancele Cáldárilor / Pesterea E, 900 m M. Beier det., 1939: / C. (Chthonius) diophthalmus Daday. / 2 ♂ ” “ Roumanie: Scárisoara. alt 900 m / R.66A (tamisage de débris ligneux) / 19.VII.1938 / R. Leruth” (IRSNB). Hunedoara: 1 ♀, Vǎlişoara, 24.VIII.1987, G. Gardini & R. Rizzerio leg.
Description of adults (♂♀). Carapace, tergites, chelicerae and pedipalps pale brown; hispid granulation on lateral surfaces of carapace, on cheliceral palm, on base of cheliceral movable finger and on distal surface of pedipalpal hand. Carapace 0.9–1.0 times longer than broad, subquadrate, slightly constricted posteriorly; anterior margin (Figs 34–35) with small epistome in both sexes; ocular area as in Fig. 36, anterior eyes with convex lens (diameter 0.040–0.045 mm), posterior ones with flat lens, all eyes with tapetum; distance from anterior eyes to anterior margin of carapace 0.030–0.035 mm; chaetotaxy mm 4mm:6:4:2:2 or m 2m (22 or 24) [no posterior microsetae reported by Mahnert (1981) and Christophoryová et al. (2011a)], macrosetae rather thick, rarely 2 posterior microsetae on one side; posterior lateral microsetae short (Fig. 36), rarely reaching half length of median macrosetae; length of anteromedian and anterolateral macrosetae respectively 0.10 and 0.085 mm, length of median macrosetae of ocular row 0.10 mm. Chaetotaxy of tergites I–X 4:4:4:4:6:6:6:6:6:4. Chaetotaxy of sternites II–X 10:(3)8–10(3):(2)7(2):8:6:6:6:6:7; genital opening of males flanked by 6–8 (usually 7) setae on each side. Chelicera (Figs 37–38) 1.7–2.1 (♂♀) times as long as broad, palm with 6 setae and 2 or 3 microsetae laterally [1 lateral microseta in Mahnert (1981)]; fixed finger with 10–12 teeth, the first two distal teeth larger; movable finger with a large isolated subapical tooth (di) and 7–8 teeth proximally reduced in size; gl ratio 0.50–0.55; spinneret absent or weakly raised in males [reported to be prominent in Mahnert (1981) and Christophoryová et al. (2011a)], prominent and apically rounded in females; rallum with 11 blades; serrulae interior and exterior respectively with 12 and 14–16 blades. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 4 + 3 marginal microsetae, II 4, III 5, IV 6; coxa II with 6–8 (rarely 4) coxal spines, coxa III with 3–4 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 4.5–5.0 (♂) or 4.7–5.2 (♀) times as long as broad; chela (Figs 39–41) 4.8–5.3 (♂) or 4.6–5.4 (♀) times as long as deep; hand of chela 1.5–1.7 (♂) or 1.5–1.75 (♀) times as long as deep, faintly depressed proximad of ib/isb; fixed chelal finger of both sexes with slight sigmoid curvature in lateral view, with 34–50 teeth: 8–14 distal teeth contiguous, pointed or apically rounded, slightly inclined backwards, first tooth distad of trichobothria dx; 9–15 large, sharp, reclined and spaced teeth without intercalary microdenticles; 9–21 proximal teeth, low, contiguous, rounded, reduced in size towards finger base; all teeth with dental canals; base of fixed chelal finger usually with few microtubercles; fixed finger at level of it/est with 4–7 teeth occupying 0.1 mm (distance between successive apices 0.016–0.025 mm); tip of fixed chelal finger with apical sensilla af1 ‾ 2, distal paraxial seta gradually curved and thin; movable chelal finger with 28–36 reclined, usually low teeth, increasingly reduced towards finger base, reaching back between sb and b, all teeth with dental canals; coupled sensilla pc halfway between st and sb or just distad of sb; tip of movable chelal finger with apical sensilla am1 ‾ 2; trichobothria as in Figs 39–41, ist distad of line eb/esb; ratio of movable finger/hand of chela 2.0–2.2 (♂) or 1.9–2.0 (♀); ratio of pedipalpal femur/movable finger 1.0 (♂♀); ratio of pedipalpal femur/carapace 1.3 (♂) or 1.2 (♀).
Measurements (in mm). Body length 1.1–1.2 (♂) or 1.2–1.5 (♀). Carapace 0.35–0.42 × 0.31–0.44 (0.36–0.40 anteriorly) (♂) or 0.38–0.42 × 0.36–0.44 (0.40–0.41 anteriorly) (♀). Chelicera 0.30–0.40 × 0.16–0.18 (♂) or 0.33–0.41 × 0.18–0.21 (♀); movable finger length 0.16–0.21 (♂) or 0.18–0.21 (♀). Pedipalp: femur 0.41–0.53 × 0.08–0.10 (♂) or 0.44–0.51 × 0.09–0.10 (♀); chela 0.63–0.81 × 0.12–0.15 (♂) or 0.68–0.77 × 0.13–0.16 (♀); hand length 0.20–0.26 (♂) or 0.22–0.25 (♀); fixed finger length (from tip to eb) 0.44–0.52 (♂) or 0.47–0.51 (♀); movable finger length 0.43–0.53 (♂) or 0.46–0.52 (♀).
Description of tritonymph. Integument weakly pigmented, hispid granulation less marked than in adults. Carapace 1.0 times longer than broad, form of anterior margin as in adults; four eyes with lenses; chaetotaxy m 4m:6:4:2:m 2m (22) [no posterior microsetae reported in Mahnert (1981)]. Chaetotaxy of tergites as in adults. Chaetotaxy of sternites II–X 5:(2)6(2):(1)6(1):7:6:6:6:6:6. Chelicera 2.1 times as long as broad, palm with 5 setae and 2 microsetae laterally [1 lateral microseta reported by Mahnert (1981)]; fixed finger with 9 teeth, the first two larger, the following proximally reduced in size; movable finger with an isolated subapical tooth (di) and 7 teeth; gl ratio 0.51; spinneret prominent and apically rounded as in females; rallum with 9 blades; serrula exterior with 13 blades. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 2 marginal microsetae, II 4, III 5, IV 5; coxa II with 5 coxal spines, coxa III with 2–3 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 4.2–4.5 times as long as broad; chela 4.6–4.8 times as long as deep; hand of chela 1.6 times as long as deep; fixed chelal finger with 30–33 teeth with dental canals: 11–12 distal teeth contiguous, pointed or apically rounded, slightly inclined backwards, first tooth distad of trichobothria dx; 12–13 large, sharp, reclined teeth; 8–10 proximal teeth, low, contiguous, rounded, reduced in size towards finger base; base of fixed chelal finger usually with a few microtubercles; fixed finger at level of it/est with 7–9 teeth occupying 0.1 mm (distance between successive apices 0.014–0.017 mm); distal paraxial seta gradually curved and thin; movable chelal finger with 23–27 triangular, reclined teeth, increasingly reduced towards finger base; coupled sensilla pc nearer to st than to b; ratio of movable finger/hand of chela 1.9–2.0; ratio of pedipalpal femur/movable finger 0.9; ratio of pedipalpal femur/carapace 1.0.
Measurements (in mm). Body length 0.98. Carapace 0.29–0.35 × 0.30–0.36. Chelicera 0.30 × 0.14, movable finger length 0.16. Pedipalp: femur 0.32–0.36 × 0.07–0.08; chela 0.49–0.56 × 0.10–0.12; hand length 0.17–0.19; fixed finger length (from tip to eb) 0.36–0.37; movable finger length 0.34–0.38.
Remarks. The redescription of C. diophthalmus given by Beier (1939a) was based on Romanian specimens of both C. heterodactylus (= C. diophthalmus) and C. hungaricus (see above, under ‘Material examined’, and ‘Remarks’ under C. heterodactylus), so it may erroneously include characters pertaining to C. hungaricus, such as the number of teeth on fixed chelal finger of females [37–40 in Beier (1939a), as opposed to 18–32 in the present redescription of C. heterodactylus].
The redescription of C. hungaricus given here incorporates data from Mahnert (1981) and Christophoryová et al. (2011a): the main discrepancies from these descriptions, reported in square brackets in the text, concern the chaetotaxy of carapace [basal row with 2 macrosetae in Mahnert (1981) and Christophoryová et al. (2011a), with 2 macro- and 2 microsetae here] and the male spinneret [prominent in Mahnert (1981) and Christophoryová et al. (2011a), absent or weakly raised here]. I suppose that these discrepancies are can be attributed to the normal range of variation in this species.
Chthonius hungaricus is an epigean species known from the inner western Carpathians and Transylvania (Fig. 90). Among the species of Chthonius of the C. heterodactylus group, C. hungaricus seems to be related to the sympatric epigean species C. heterodactylus. Differences between C. hungaricus and C. heterodactylus are given in the above key.
Chthonius hungaricus and Mundochthonius carpaticus are newly recorded for Romania (see material examined above).
description: Published as part of Gardini, Giulio, 2014, The species of the Chthonius heterodactylus group (Arachnida, Pseudoscorpiones, Chthoniidae) from the eastern Alps and the Carpathians, pp. 101-137 in Zootaxa 3887 (2) on pages 114-117, DOI: 10.11646/zootaxa.3887.2.1, http://zenodo.org/record/228058