Research Article |
Corresponding author: Martina Červená ( martinacervena.lr@gmail.com ) Academic editor: Mark Judson
© 2019 Martina Červená, František Šťáhlavský, Vladimír Papáč, Ľubomír Kováč, Jana Christophoryová.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Červená M, Šťáhlavský F, Papáč V, Kováč Ľ, Christophoryová J (2019) Morphological and cytogenetic characteristics of Neobisium (Blothrus) slovacum Gulička, 1977 (Pseudoscorpiones, Neobisiidae), the northernmost troglobitic species of the subgenus Blothrus in Europe. ZooKeys 817: 113-130. https://doi.org/10.3897/zookeys.817.27189
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A redescription is provided of the adult, tritonymph and deutonymph life stages of the troglobitic Neobisium (Blothrus) slovacum Gulička, 1977, which is known from Slovakia and Hungary. Material examined included 35 previously deposited museum specimens and 15 newly collected specimens. In addition, the karyotype and distribution of 18S rDNA clusters are described, using fluorescence in situ hybridization (FISH). The male karyotype of N. slovacum comprises 69 chromosomes, with a predominance of biarmed chromosomes, and an X0 sex chromosome system. Two pairs of signals for 18S rDNA on biarmed chromosomes (submetacentric and metacentric) of different sizes were identified. The present study provides the first information about the distribution of these clusters in the arachnid order Pseudoscorpiones. The geographic distribution of the species is summarized and mapped. Neobisium slovacum is endemic to the Slovak and Aggtelek Karst area in southern Slovakia and north-western Hungary, where it has been recorded from 16 caves. One of these, Hačavská cave (in Slovakia), is the northernmost locality known for any species of the subgenus Blothrus.
Distribution, endemic, FISH, sex chromosome, Slovak Karst, troglobitic, 18S rDNA
In Europe, troglobitic pseudoscorpions of the genus Neobisium Chamberlin, 1930 occur in four subgenera: Blothrus Schiödte, 1847, Ommatoblothrus Beier, 1956, Heoblothrus Beier, 1963 and Pennobisium Ćurčić, 1988. Of these, Blothrus is the most frequent genus in European caves (
In Slovakia, the sole species of the subgenus Blothrus is Neobisium slovacum Gulička, 1977, which has clear troglomorphic characters (
Neobisium slovacum is a strictly troglobitic species, with specific morphological adaptations to the cave environment. Compared to epigean relatives, the body of N. slovacum is pale, the legs and pedipalps are elongated, and eyes are absent. The remarkably elongated appendages provide an advantage in locating and capturing prey in the cave environment. The specimens are usually found on walls, in stony debris with clay sediments and near organic material (bat guano) in caves (
The species was originally described from Stará brzotínska cave by
Later,
After Stará brzotínska cave, the species was found at 14 other localities in the Slovak Karst (Fig.
List of collection localities of Neobisium slovacum in the Slovak Karst area (1–15 Slovakia; 16 Hungary). Abbreviations: a.s.l., above sea level; N, latitude; W, longitude (see map, Fig.
Code | Locality | N | W | m a.s.l. |
---|---|---|---|---|
1 | Stará brzotínska cave (type locality) | 48°36'32", 20°28'15" | 258 | |
2 | Zvonivá chasm | 48°37'04", 20°25'33" | 675 | |
3 | Zombor chasm | 48°36'48", 20°26'38" | 645 | |
4 | Diviačia chasm | 48°35'02", 20°26'30" | 597 | |
5 | Čikova diera cave | 48°34'14", 20°24'50" | 526 | |
6 | Fialová cave | 48°34'12", 20°24'55" | 544 | |
7 | Šingliarova chasm | 48°39'21", 20°25'04" | 677 | |
8 | Obrovská chasm | 48°34'04", 20°41'05" | 535 | |
9 | Pri salaši 2 chasm | 48°34'21", 20°43'20" | 543 | |
10 | Natrhnutá chasm | 48°34'00", 20°43'56" | 508 | |
11 | Erňa cave | 48°36'56", 20°50'36" | 410 | |
12 | Slnečná chasm | 48°35'60", 20°24'83" | 564 | |
13 | Vlčia chasm | 48°36'89", 20°27'05" | 660 | |
14 | Veľká Peňažnica chasm | 48°35'83", 20°27'12" | 667 | |
15 | Hačavská cave | 48°39'50", 20°49'47" | 795 | |
16 | Meteor cave | 48°33'11", 20°42'26" | 443 |
Although N. slovacum seems to be restricted to the cave systems of the Slovak and Aggtelek Karst area, the possibility exists that the isolation of populations in separate cave systems could have led to diversification and cryptic speciation in this region. The detection of cryptic species diversity has recently been based mainly on the analysis of mitochondrial and nuclear gene sequences in terrestrial (e.g.
Summarizing the previously published data, 61 adults and six nymphs have been collected from Slovakia. Despite this, knowledge of the morphology of N. slovacum remained incomplete. All previous descriptions were deficient in important details. Consequently, the aims of the present study are to: (1) complete and examine previously studied material of N. slovacum, (2) describe newly collected specimens and provide additional information on the variability of morphometric and morphological characters, (3) analyse the N. slovacum karyotype and (4) analyse the distribution of N. slovacum in caves of the Western Carpathians.
To locate previously studied material of N. slovacum, the natural history museums in Vienna, Bratislava and Berlin, and the zoology departments of Charles University in Prague and Comenius University in Bratislava were contacted. In total, 35 specimens from eight localities in the Slovak Karst were obtained, including one specimen from the type locality. These specimens have been deposited in the Department of Zoology of Charles University in Prague and the Natural History Museum in Vienna (NHMW). The recently collected specimens of N. slovacum (15 specimens) were obtained at three localities of the Slovak Karst: Šingliarova chasm, Hačavská cave and Zvonivá chasm. The new material from Hačavská cave and Šingliarova chasm was deposited in the Natural History Museum in Vienna (NHMW) and material from the Zvonivá chasm in the Department of Zoology, Charles University in Prague.
Recently collected specimens were identified using the identification keys in
One male from Zvonivá chasm (locality 2: Table
The chromosomes were prepared by the “spreading” method described in
Neobisium (Blothrus) slovacum
Gulička, 1977a: 6–8, figs 1–4;
Neobisium slovacum is an eyeless, troglobitic species that differs from other Carpathian species of the subgenus Blothrus in following combination of characters: posterior margin of carapace usually with 4 setae; a subocular seta usually present (sometimes missing on one side); epistome absent; cheliceral hand with 5 setae; anterolateral process of coxa I long, broad and apically pointed, medial process prominent, rounded, with strong denticles; palpal trochanter without tubercles; palpal femur ratio in the range 5.69–8.81 mm; fixed palpal finger with unequally long teeth; telotarsus IV with 2 long tactile setae. Chromosomes of male 2n = 69.
Slovakia, Slovak Karst, Stará brzotínska cave (48°36'32"N; 20°28'15"E, 258 m a.s.l., length 120 m).
Adult of undetermined sex collected from stony debris on clay sediment on 26 September 1974. Apparently lost.
2 nymphs, from type locality, collected on 10 August 1975. Apparently lost.
The depository of the type material is unknown. Searches for the holotype and paratypes in various institutions (listed in Methods section) were unsuccessful.
(see Table
Čikova diera cave (length 60 m, depth 26 m): 1 ♀ (det. V. Ducháč), 21 February–13 March 1988, leg. R. Mlejnek; 1 ♂ (det. V. Ducháč), 12 May 1988, leg. R. Mlejnek; 1 ♀ (det. V. Ducháč), 9 June 1989, leg. R. Mlejnek; Diviačia chasm (length 468 m, depth 127 m): 1 ♂, 2 ♀ (det. V. Ducháč), 1966, leg. V. Lysenko; Erňa cave (length 60 m, depth 10 m): 2 ♀, 1 specimen represented by appendages only, sex unknown (det. V. Ducháč), 20 July 1999, leg. R. Mlejnek; Fialová cave (length 21 m, depth 5.5 m): 1 ♀ (det. V. Ducháč), 15 April 1989, leg. R. Mlejnek; 1 ♂ (det. V. Ducháč), 23 September 1989, leg. R. Mlejnek; 1 ♂, 1 ♀, 1 tritonymph (det. V. Ducháč), 17 January 1998, leg. R. Mlejnek; 1 ♂ (det. V. Ducháč), 11 May 1998, leg. R. Mlejnek; Obrovská chasm (depth 100 m): 1 ♂ (det. V. Ducháč), 8 May 1988, leg. R. Mlejnek; Pri salaši 2 chasm (length 50 m, depth 36 m): 1 specimen represented by appendages only (det. V. Ducháč), 8 May 1988, leg. R. Mlejnek; Stará brzotínska cave (length 120 m): 1 ♀ (NHMW 28661) (det. V. Ducháč), 6 June 1982, leg. P. Moravec; Šingliarova chasm (length 140 m, depth 72 m): 3 ♂, 1 ♀ and 1 ♀ damaged badly (det. V. Ducháč), 12 May 1988, leg. R. Mlejnek; 1 ♂ (det. V. Ducháč), 7 June–19 October 1998, leg. R. Mlejnek; 3 ♂, 3 ♀, 2 specimens (sex unknown) represented by appendages only (det. V. Ducháč), 16 May 1998, leg. R. Mlejnek; Unknown locality: 1 ♂ (NHMW 28664), 2 ♀ (NHMW 28664) (det. V. Ducháč), 4 March 2003, leg. R. Mlejnek, locality data missing.
Faunistic data and descriptions of the 35 specimens listed above were provided by
Hačavská cave (length 200 m): 2 ♂, 1 ♀ (NHMW 28662); hand sampling, in stony debris with clay sediment, back part of the cave, 150 m in the cave from entrance, 3 April 2017, leg. V. Papáč; Šingliarova chasm (length 140 m, depth 72 m): 1 ♂, 2 ♀, 1 deutonymph (NHMW 28659), pitfall trapping, 11 October 2003, leg. A. Mock; 2 ♂, 1 ♀, hand sampling, 2 May 2007, leg. Ľ. Kováč; 2 ♂, 1 ♀ (NHMW 28660), hand sampling, on cave walls and rocks, Second Hall, 25 August 2012, leg. P. Ľuptáčik; Zvonivá chasm (length 494 m): 2 ♀, hand sampling, 5 May 2006, leg. Ľ. Kováč.
Šingliarova chasm: 2 May 2007: 2 ♂, hand sampling, leg. Ľ. Kováč; Zvonivá chasm: 5 May 2006: 1 ♂, hand sampling, leg. Ľ. Kováč.
The newly collected specimens are described here, except for those used in the cytogenetic analyse. The record of the four specimens (NHMW 28659) from Šingliarova chasm was previously published by
In total, 40 adults, 1 tritonymph and 1 deutonymph were examined in the present study. Measurements of adults are given in Table
Morphometric data for males and females of Neobisium slovacum (measurements in mm). Abbreviations: M, median; Min, minimum; Max, maximum; N, number of individuals measured; SD, standard deviation; x¯, arithmetic mean.
Characteristics | Males | Females | ||||
Min–Max | M/x¯±SD | N | Min–Max | M/x¯±SD | N | |
Body, length | 2.80–3.97 | 3.54/3.18±1.05 | 11 | 3.00–3.90 | 3.38/3.42±0.30 | 14 |
Carapace, length | 0.91–1.19 | 1.04/1.00±0.24 | 19 | 0.95–1.18 | 1.05/1.06±0.07 | 18 |
Carapace, posterior width | 0.86–1.08 | 0.97/0.92±0.25 | 15 | 0.85–1.20 | 0.97/1.00±0.11 | 15 |
Carapace, length/posterior width ratio | 0.98–1.13 | 1.07/1.01±0.28 | 15 | 0.92–1.24 | 1.08/1.08±0.09 | 14 |
Chelicera, length | 0.61–0.78 | 0.69/0.66±0.16 | 19 | 0.67–0.80 | 0.69/0.71±0.04 | 18 |
Chelicera, width | 0.29–0.40 | 0.36/0.34±0.08 | 20 | 0.35–0.43 | 0.37/0.38±0.02 | 19 |
Chelicera, length/width ratio | 1.79–2.06 | 1.92/1.82±0.43 | 19 | 1.74–1.95 | 1.89/1.87±0.06 | 18 |
Cheliceral movable finger, length | 0.37–0.49 | 0.44/0.42±0.10 | 20 | 0.42–0.50 | 0.46/0.46±0.02 | 19 |
Palpal trochanter, length | 0.65–0.82 | 0.72/0.70±0.17 | 19 | 0.66–0.84 | 0.74/0.74±0.05 | 19 |
Palpal trochanter, width | 0.20–0.35 | 0.28/0.26±0.07 | 20 | 0.25–0.35 | 0.29/0.29±0.03 | 20 |
Palpal trochanter, length/width ratio | 2.03–3.09 | 2.58/2.50±0.65 | 19 | 2.09–2.89 | 2.50/2.54±0.18 | 19 |
Palpal femur, length | 1.66–1.93 | 1.76/1.67±0.41 | 18 | 1.52–1.85 | 1.74/1.73±0.08 | 20 |
Palpal femur, width | 0.20–0.27 | 0.22/0.21±0.05 | 20 | 0.19–0.32 | 0.23/0.23±0.03 | 20 |
Palpal femur, length/width ratio | 6.52–8.81 | 7.96/7.38±1.87 | 18 | 5.69–8.74 | 7.65/7.60±0.74 | 20 |
Palpal patella, length | 1.46–1.67 | 1.56/1.49±0.37 | 18 | 1.41–1.61 | 1.49/1.51±0.06 | 19 |
Palpal patella, width | 0.20–0.30 | 0.24/0.24±0.06 | 20 | 0.22–0.32 | 0.26/0.26±0.03 | 20 |
Palpal patella, length/width ratio | 5.20–6.75 | 6.17/5.79±1.48 | 18 | 5.00–6.83 | 5.88/5.82±0.53 | 19 |
Palpal hand, length with pedicel | 1.01–1.32 | 1.17/1.12±0.27 | 19 | 1.05–1.25 | 1.15/1.16±0.05 | 19 |
Palpal hand, length without pedicel | 1.01–1.14 | 1.06/1.01±0.26 | 17 | 0.90–1.14 | 1.04/1.04±0.06 | 19 |
Palpal hand, width | 0.33–0.47 | 0.40/0.38±0.09 | 20 | 0.36–0.52 | 0.41/0.42±0.05 | 19 |
Palpal hand, length with pedicel/width ratio | 2.43–3.40 | 2.95/2.82±0.70 | 19 | 2.21–3.19 | 2.80/2.76±0.26 | 18 |
Palpal finger, length | 1.81–2.09 | 1.92/1.82±0.45 | 18 | 1.81–2.06 | 1.91/1.92±0.08 | 18 |
Palpal finger, length/palpal hand length with pedicel | 1.52–1.69 | 1.61/1.53±0.37 | 18 | 1.59–1.77 | 1.66/1.66±0.05 | 16 |
Palpal chela, length | 2.57–3.19 | 2.91/2.77±0.67 | 19 | 2.73–3.21 | 2.91/2.93±0.14 | 17 |
Palpal chela, width | 0.33–0.47 | 0.40/0.38±0.09 | 20 | 0.36–0.52 | 0.41/0.42±0.05 | 17 |
Palpal chela, length/width ratio | 6.43–7.94 | 7.33/6.97±1.70 | 19 | 5.67–8.08 | 7.04/6.99±0.63 | 15 |
Leg I trochanter, length | 0.30–0.38 | 0.34/0.32±0.08 | 18 | 0.28–0.37 | 0.33/0.33±0.03 | 18 |
Leg I trochanter, depth | 0.18–0.23 | 0.20/0.19±0.05 | 18 | 0.17–0.24 | 0.21/0.21±0.02 | 18 |
Leg I trochanter, length/depth ratio | 1.48–1.79 | 1.60/1.53±0.39 | 17 | 1.33–1.94 | 1.55/1.62±0.17 | 17 |
Leg I femur, length | 0.88–1.02 | 0.94/0.89±0.23 | 17 | 0.75–1.03 | 0.90/0.91±0.08 | 17 |
Leg I femur, depth | 0.09–0.14 | 0.11/0.11±0.03 | 18 | 0.10–0.15 | 0.11/0.12±0.02 | 17 |
Leg I femur, length/depth ratio | 6.79–9.78 | 8.18/7.83±2.10 | 17 | 6.67–9.36 | 7.70/7.84±0.79 | 17 |
Leg I patella, length | 0.50–0.71 | 0.63/0.60±0.15 | 19 | 0.56–0.69 | 0.62/0.62±0.04 | 18 |
Leg I patella, depth | 0.10–0.15 | 0.12/0.11±0.03 | 19 | 0.11–0.16 | 0.12/0.12±0.01 | 16 |
Leg I patella, length/depth ratio | 4.20–6.80 | 5.32/5.11±1.38 | 19 | 4.00–6.00 | 5.12/5.07±0.53 | 16 |
Leg I tibia, length | 0.64–0.82 | 0.73/0.69±0.17 | 18 | 0.65–0.77 | 0.72/0.71±0.04 | 19 |
Leg I tibia, depth | 0.08–0.10 | 0.09/0.09±0.02 | 18 | 0.08–0.11 | 0.09/0.09±0.01 | 19 |
Leg I tibia, length/depth ratio | 7.33–9.63 | 7.95/7.67±1.99 | 17 | 6.50–9.38 | 7.67/7.90±0.84 | 19 |
Leg I basitarsus, length | 0.40–0.49 | 0.45/0.42±0.11 | 17 | 0.37–0.47 | 0.43/0.43±0.03 | 20 |
Leg I basitarsus, depth | 0.06–0.09 | 0.08/0.08±0.02 | 19 | 0.06–0.10 | 0.09/0.08±0.01 | 20 |
Leg I basitarsus, length/depth ratio | 4.89–7.50 | 5.13/5.11±1.42 | 17 | 4.44–7.83 | 4.89/5.15±0.78 | 20 |
Leg I telotarsus, length | 0.48–0.63 | 0.55/0.53±0.13 | 18 | 0.40–0.62 | 0.56/0.55±0.05 | 18 |
Leg I telotarsus, depth | 0.07–0.10 | 0.08/0.08±0.02 | 18 | 0.07–0.10 | 0.08/0.08±0.01 | 16 |
Leg I telotarsus, length/depth ratio | 6.11–8.43 | 6.87/6.49±1.73 | 17 | 5.00–8.86 | 6.75/6.66±1.04 | 16 |
Leg IV trochanter, length | 0.50–0.63 | 0.55/0.52±0.13 | 17 | 0.49–0.65 | 0.55/0.56±0.04 | 19 |
Leg IV trochanter, depth | 0.17–0.28 | 0.22/0.21±0.06 | 17 | 0.19–0.28 | 0.22/0.23±0.03 | 19 |
Leg IV trochanter, length/depth ratio | 1.79–3.11 | 2.59/2.41±0.71 | 16 | 1.96–2.95 | 2.50/2.48±0.31 | 19 |
Leg IV femoropatella, length | 1.44–1.75 | 1.62/1.51±0.40 | 16 | 1.40–1.75 | 1.58/1.56±0.08 | 17 |
Leg IV femoropatella, depth | 0.18–0.30 | 0.23/0.22±0.06 | 17 | 0.21–0.31 | 0.24/0.24±0.03 | 16 |
Leg IV femoropatella, length/depth ratio | 5.47–8.72 | 6.91/6.45±1.83 | 16 | 5.10–7.33 | 6.55/6.47±0.67 | 15 |
Leg IV tibia, length | 1.40–1.64 | 1.49/1.41±0.36 | 17 | 1.32–1.56 | 1.43/1.44±0.08 | 17 |
Leg IV tibia, depth | 0.12–0.17 | 0.13/0.13±0.03 | 19 | 0.11–0.16 | 0.13/0.13±0.01 | 18 |
Leg IV tibia, length/depth ratio | 9.33–12.67 | 10.97/10.45±2.76 | 17 | 9.64–13.00 | 11.50/11.35±0.85 | 17 |
Leg IV basitarsus, length | 0.51–0.64 | 0.56/0.54±0.14 | 17 | 0.49–0.60 | 0.56/0.55±0.03 | 18 |
Leg IV basitarsus, depth | 0.10–0.13 | 0.11/0.10±0.03 | 19 | 0.09–0.13 | 0.11/0.11±0.01 | 18 |
Leg IV basitarsus, length/depth ratio | 4.25–5.82 | 5.27/4.95±1.33 | 17 | 4.46–6.44 | 5.05/5.19±0.51 | 18 |
Leg IV telotarsus, length | 0.81–0.93 | 0.87/0.82±0.21 | 16 | 0.74–0.96 | 0.85/0.85±0.06 | 17 |
Leg IV telotarsus, depth | 0.09–0.11 | 0.10/0.10±0.03 | 17 | 0.09–0.13 | 0.11/0.10±0.01 | 18 |
Leg IV telotarsus, length/depth ratio | 7.73–10.33 | 8.24/7.94±2.24 | 15 | 6.25–10.67 | 8.27/8.28±1.24 | 17 |
Adults. Body yellowish; carapace, chelicerae and pedipalps light brown. Vestitural setae of body and pedipalps long and pointed. Carapace rectangular, without granulation, longer than broad, epistome and eyes absent, a subocular seta usually present (sometimes missing on one side). Tergites and sternites undivided. Chelicera with 5 setae on hand, 1 seta on movable finger, spinneret well developed in female, weak in male, rallum of 8 blades, 2 distal blades dentate. Anterolateral process of coxa I long, broad and apically pointed, medial process prominent, rounded, with strong denticles. Pedipalps slender, chelal fingers with normal number of trichobothria (8 on fixed and 4 on movable finger), sensillum p1 slightly distal of st, p2 nearer to st than to sb, situated close to dental margin. Palpal trochanter without tubercles. Legs elongated, I–IV with 2 tarsal segments (basitarsus and telotarsus separated). Subterminal setae of telotarsi I and IV with short, smooth, ventral rami and small dorsal denticles in distal part. Telotarsus IV with 2 long tactile setae, telotarsus I without tactile seta. Claws with a small dorsal denticle about one-third from base.
Males (20 specimens studied). Chaetotaxy of carapace: total 16–21 setae, posterior margin mostly with 4 setae, exceptionally with 3 setae in 2 males and 5 setae in 1 male, anterior margin mostly with 4 setae, exceptionally with 3 setae in 2 males and 5 setae in 2 males. Chaetotaxy of tergites I–X: 4, 4, 4–6, 4–6, 4–7, 4–6, 5–7, 5–7, 6–7, 5–7. Chaetotaxy of sternites IV–X: 7–15, 8–12, 8–11, 8–11, 9–11, 8–10, 7–9. Anterior genital operculum with 9–19 setae, posterior genital operculum with 29–38 setae in total, comprised of 19–26 medial and 8–15 marginal setae. Chelicera: fixed finger with 12–22 and movable finger with 10–20 unequally long teeth. Pedipalp: fixed finger with 133–172 unequally long teeth and movable finger with 106–152 equally long teeth. See Table
Females (20 specimens studied). Chaetotaxy of carapace: total 16–20 setae, posterior margin mostly with 4 setae, exceptionally with 2 setae in 1 female, anterior margin mostly with 4 setae exceptionally with 5 setae in 2 females. Chaetotaxy of tergites I–X: 4–5, 4–5, 4–6, 4–6, 4–6, 5–6, 5–7, 5–8, 5–7, 5–7. Chaetotaxy of sternites IV–X: 6–13, 6–10, 8–11, 8–11, 8–12, 8–11, 7–9. Anterior genital operculum with 7–13 setae, posterior operculum with 12–18 setae. Chelicera: fixed finger with 14–20 and movable finger with 11–19 unequally long teeth. Pedipalp: fixed finger with 131–171 unequally long teeth and movable finger with 118–149 equally long teeth. See Table 2 for measurements.
Tritonymph (1 specimen studied). With same general characteristics as adults. Chaetotaxy of carapace: total 17 setae, posterior and anterior margin with 4 setae each. Chaetotaxy of tergites I–X: 4, 5, 5, 4, 6, 6, 6, 6, 6, 6. Chaetotaxy of sternites IV–X: 8, 11, 10, 11, 10, 8, 8. Chelicera: rallum of 8 blades, 2 distal blades dentate, fixed finger with 14 and movable finger with 13 unequally long teeth. Pedipalps: chela with 7 trichobothria on fixed finger and 3 on movable finger; fixed finger with 112 equally long marginal teeth, movable finger with 97 equally long marginal teeth.
Measurements of tritonymph. Body length 3.43. Chelicera: 0.54/0.27 (×2.00); movable finger length 0.35. Pedipalps: trochanter 0.53/0.23 (×2.30), femur 1.10/0.19 (×5.79), patella 0.96/0.20 (×4.80), palpal hand 0.81/0.24 (×3.38), hand length without pedicel 0.73, movable finger length 1.26, movable finger and hand length ratio 1.56, palpal chela 1.95/0.24 (×8.13). Leg I: femur 0.59/0.10 (×5.90), patella 0.39/0.10 (×3.90), tibia 0.47/0.07 (×6.71), basitarsus 0.27/0.08 (×3.38), telotarsus 0.41/0.10 (×4.10). Leg IV: trochanter 0.38/0.18 (×2.11), femoropatella 0.96/0.18 (×5.33), tibia 0.88/0.11 (×8.00), basitarsus 0.35/0.10 (×3.50), telotarsus 0.57/0.12 (×4.75).
A description of this tritonymph was previously published by
Deutonymph (1 specimen studied). With same general characteristics as adults. Chaetotaxy of carapace: total 19 setae, posterior margin with 5, anterior margin with 4 setae. Chaetotaxy of tergites I–X: 3, 4, 5, 6, 6, 6, 6, 6, 6, 5. Chaetotaxy of sternites IV–X: 8, 8, 8, 8, 8, 8, 7. Chelicera: rallum of 6 blades, 2 distal blades dentate; fixed finger with 14 and movable finger with 11 unequal teeth. Pedipalps: chelal with 6 trichobothria on fixed finger and 2 on movable finger; fixed finger with 73 equally long teeth, movable finger with 66 equally long teeth.
Measurements of deutonymph. Body length 2.57. Carapace: 0.68/0.66 (×1.03). Chelicera: 0.41/0.24 (×1.71); movable finger length 0.26. Pedipalps: trochanter 0.38/0.19 (×2.00), femur 0.76/0.15 (×5.07), patella 0.62/0.20 (×3.10), palpal hand 0.57/0.27 (×2.11), hand length without pedicel 0.53, movable finger length 0.91, movable finger and hand length ratio 1.60, palpal chela 1.33/0.27 (×4.93). Leg I: trochanter 0.20/0.13 (×1.54), femur I 0.40/0.09 (×4.44), patella 0.26/0.08 (×3.25), tibia 0.29/0.07 (×4.14), basitarsus 0.16/0.07 (×2.29), telotarsus 0.27/0.08 (×3.38). Leg IV: trochanter 0.24/0.16 (×1.50), femoropatella 0.69/0.15 (×4.60), tibia 0.54/0.09 (×6.00), basitarsus 0.24/0.09 (×2.67), telotarsus 0.39/0.09 (×4.33).
The diploid complement of all three males analysed was 69 chromosomes (Fig.
The original description of N. slovacum by
The redescription of previously studied and newly obtained material in the present paper gives a better assessment of intraspecific variability and adds some previously unstudied characters, such as the chaetotaxy of sternites, measurements of legs and the number of teeth on cheliceral and palpal fingers, presence of subocular setae, anterolateral and medial processes of coxa I, positions of chelal sensilla p1 and p2, form of subterminal seta, tactile seta of legs I and IV and denticulation of leg claws. The individuals show great variability in some characters, such as palpal femur and trochanter length, palpal chela length/width ratio, femur I and telotarsus I length/depth ratio, tibia IV and telotarsus IV length/depth ratio, femoropatella IV length/depth ratio in males, number of teeth on chelal and palpal fingers, chaetotaxy of sternites, and chaetotaxy of the male genital operculum. However, no significant differences were observed in chaetotaxy or measurements between populations of different caves. The greatest variability was observed in the palpal femur length/width ratio, with a range of 5.69–8.81 mm.
Concerning the karyotype, no differences were observed between the three males analysed. It should be noted that the material used for cytogenetic analysis comes only from two localities (Fig.
Summarizing all known distributional records, N. slovacum is currently known from 15 localities in the Slovakia and one locality in Hungary (Table
We are grateful to our colleagues Andrej Mock and Peter Ľuptáčik for collecting the new material of Neobisium slovacum. We thank Ivica Hlaváčová for providing accurate cave data, Daniel Jablonski for technical assistance with maps as well as Jana Štundlová for technical assistance during probe preparation. We are grateful to our colleagues, Katarína Krajčovičová and Peter Vďačný, and the reviewers, James Cokendolpher and the late Volker Mahnert, for valuable and constructive comments that improved the quality of the paper. Collection of this species was authorized by the Ministry of Environment of the Slovak Republic according to law §29 of the Nature and Landscape Protection Act (no. 543/2002). The project was financially supported by VEGA grant 1/0191/15.