Roncus travuniensis sp. n. (Neobisiidae, Pseudoscorpiones), a troglobitic false scorpion from Bosnia-Herzegovina

Biologia, Bratislava, 62/1: 84—87, 2007 Section Zoology DOI: 10.2478/s11756-007-0014-7

Roncus travuniensis sp. n. (Neobisiidae, Pseudoscorpiones), a troglobitic false scorpion from Bosnia-Herzegovina ´ ´ & Rajko N. Dimitrijevic ´ Božidar P.M. Curči c Institute of Zoology, Faculty of Biology, University of Belgrade, Studentski Trg 16, 11000 Belgrade, Serbia; e-mail: [email protected]

Abstract: A new pseudoscorpion species, Roncus travuniensis sp. n. (Neobisiidae, Pseudoscorpiones), was collected in the Arenstorfova Pe´cina Cave, near Trebinje, Bosnia and Herzegovina. The main morphological traits of the specimen studied clearly demonstrate its affinities with Roncus vulcanius Beier, 1938. Additionally, some taxonomic and biogeographical traits of this new pseudoscorpion are also discussed. Key words: pseudoscorpions; Neobisiidae; Roncus travuniensis; cave fauna; Bosnia and Herzegovina

Introduction Despite the enormous growth of ecological investigations in recent decades (Harvey 1990), pseudoscorpions in Bosnia and Herzegovina (and especially in Herzegov´ ina) have seldom received attention (Curči´ c 1974). This is remarkable because they inhabit strata from leaflitter to deep soil and are more or less associated with many groups of soil- and cave-living organisms. The reason may be their small body size, scattered literature, and anticipated low population density. Another reason, probably responsible for the low number of records in biospeleological literature, is that pseudoscorpions still are unfamiliar to many, ever well-trained soil and cave biologists. It is well known that some species of caveinhabiting animals occur in exceedingly low population densities while others may occur in remarkably high numbers. The pseudoscorpions probably belong to the former group and seem to be rare in caves, but there is no doubt that a great number of subterranean species still remain to be discovered. A thorough study of some pseudoscorpions from a small collection, made by Ivo M. Karaman (Novi Sad), has yielded a new species of the genus Roncus L. Koch, 1873; it is ascertained to a new species, Roncus travuniensis sp. n. (Neobisiidae). This paper presents description of the new species and compares this taxon with its phenetically close relatives. Furthermore, some taxonomic, ecological, and biogeographical features of these species are briefly discussed. Material and methods The holotype female studied was mounted on slides in

c 2007 Institute of Zoology, Slovak Academy of Sciences


Swan’s fluid (gum chloral medium) and deposited in the collections of the Institute of Zoology, Faculty of Biology, University of Belgrade, 11000 Belgrade (IZBF 0101). ´ Setal designations follow Beier (1932) and Curči´ c (1977).

Neobisiidae J.C. Chamberlin, 1930 Roncus L. Koch, 1873 Roncus travuniensis sp. n. (Figs 1–8, Table 1) Description. Epistome small, knob-like (Figs 4, 6). The dorsal side of the cephalothorax (carapace) is considerably longer than wide (Fig. 6; Table 1). The carapacal setation is 4 + 6 + 7 + 6 = 23 (Fig. 6); the probable setal formula is either 4 + 6 + 6 + 6 = 22 or 4 + 6 + 8 + 6 = 24 setae. Eyes absent (Fig. 6). The number of setae on tergites I–X is variable. In holotype female, tergal formula is 6-8-9-10-10-10-9-9-98 setae. Twelfth abdominal segment with two pairs of small setae. In the female, sternite II bears eight setae, sternite III – 12 posterior setae and three suprastigmatic setae on either side, sternite IV – 11 posterior setae and three small setae along each stigma (Fig. 7); sternites V–X with 15-15-14-14-13-13 setae. Male genital area unknown. The form of the chelicerae is presented in Fig. 8. Cheliceral spinneret is a low hyaline convexity. The movable and fixed cheliceral fingers each carry a variable number of teeth – eight on the former and 11 or 12 on the latter finger. Six setae occur on the cheliceral palm, while a single seta is borne on the movable finger. Flagellum of eight blades; all blades pinnate anteriorly; seven anterior blades of approximately same size; the proximalmost blade is the smallest (Fig. 5). The mov-

New troglobitic pseudoscorpion from Bosnia-Herzegovina

85

Figs 1–8. Roncus travuniensis sp. n., holotype female, from the Arenstorfova Pe´cina Cave, nr. Trebinje, Bosnia and Herzegovina: 1 – pedipalp; 2 – leg IV; 3 – pedipalpal chela; 4 – epistome; 5 – flagellum; 6 – carapace; 7 – female genital area; 8 – chelicera. Scales 0.25 mm (Figs 4, 5, 7, 8) and 0.50 mm (Figs 1–3, 6).

able cheliceral finger is considerably longer than the cheliceral width. Chelicera is almost twice as long as wide (Table 1). Apex of pedipalpal coxa (manducatory process) carries four long and acuminate setae. Pedipalpal articles elongated, pedipalpal patella and chelal palm with interior and lateral granulations; other articles smooth (Figs 1, 3). Pedicel of patella shorter than club; finger indistinctly shorter than chelal palm with pedicel (Table 1); femur with distinct pedicel, widest distal of mid-

dle and club-shaped (Fig. 1). The movable chelal finger with 73 small and contiguous teeth, while 77 such teeth are borne on the fixed chelal finger. Four trichobothria are carried on the movable chelal finger and eight on the fixed chelal finger, characteristic of the genus (Fig. 3). The trichobothrium ist almost equidistant from isb and est (Fig. 3). The trichobothrium sb closer to b than to st, st closer to t than to sb (Fig. 3). Only three microsetae are found anterior to eb and esb (Fig. 3).

´ ´ & R.N. Dimitrijevic ´ B.P.M. Curči c

86 Table 1. Linear measurements (in millimeters) and morphometric ratios in female Roncus travuniensis sp. n. from Bosnia and Herzegovina.

Etymology. After Travunia, the Latin name for the old settlement of Trebinje.

Character Body Length (1) Cephalothorax Length (2) Width (2a) Ratio 2/2a Abdomen Length Chelicerae Length (3) Width (4) Length of movable finger (5) Ratio 3/5 Ratio 3/4 Pedipalps Length with coxa (6) Ratio 6/1 Length of coxa Length of trochanter Length of femur (7) Width of femur (8) Ratio 7/8 Ratio 7/2 Length of patella (tibia) (9) Width of patella (tibia) (10) Ratio 9/10 Length of chela (11) Width of chela (12) Ratio 11/12 Length of chelal palm (13) Ratio 13/12 Length of chelal finger (14) Ratio 14/13 Leg IV Total length Length of coxa Length of trochanter (15) Width of trochanter (16) Ratio 15/16 Length of femur + patella (17) Width of femur + patella (18) Ratio 17/18 Length of tibia (19) Width of tibia (20) Ratio 19/20 Length of metatarsus (21) Width of metatarsus (22) Ratio 21/22 Length of tarsus (23) Width of tarsus (24) Ratio 23/24 TS ratio – tibia IV TS ratio – metatarsus IV TS ratio – tarsus IV

Material examined. Holotype: female, Bosnia and Herzegovina, Arenstorfova Pe´cina Cave, near Trebinje (18◦ 20 E, 42◦ 43 N), 10.VI.2005, leg. I. M. Karaman.

2.845 0.92 0.80 1.15 1.925 0.64 0.33 0.44 1.45 1.94 5.83 2.03 0.75 0.67 1.19 0.305 3.90 1.29 1.02 0.41 2.49 2.20 0.63 3.49 1.11 1.76 1.09 0.98 3.58 0.41 0.45 0.17 2.65 0.99 0.315 3.14 0.94 0.15 5.875 0.30 0.11 2.73 0.49 0.10 4.90 0.47 0.17 0.35

The pedipalpal femur is 3.90 times as long as wide (Table 1). This podomere is considerably longer than carapace. The pedipalpal tibia is 2.49 times as long as wide, the pedipalpal chelal length to width ratio is 3.49; chelal palm length/width ratio exceeds 1.76 (Table 1). Leg IV: tibia, metatarsus, and tarsus each carry a long tactile seta (Fig. 2; Table 1). The measurements of different body structures and morphometric ratios are shown in Table 1, while the main diagnostic characters are presented in Figs 1–8.

Differential diagnosis. Only two species of the genus Roncus are presently known from Bosnia and Herzegovina (Harvey 1990): Roncus anophthalmus (Ellingsen, 1910) and Roncus vulcanius vulcanius Beier, 1938, both from S Herzegovina. From R. anophthalmus, from near Bihovo, R. travuniensis sp. n. is easily distinguished by the presence/absence of granulations on the pedipalpal femur (absent vs. present), by the pedipalpal chela length/ width ratio (3.10 vs. 3.49), in the setation of tergites I–V (6-10-12-12-12 vs. 6-8-9-10-10), and in the form of the pedipalpal articles (Fig. 1 vs. Fig. 195; Beier 1963). R. travuniensis sp. n. differs from R. vulcanius vulcanius Beier, 1938 (from near Trebinje) in the pedipalpal femur length (1.19 mm vs. 0.95–1.10 mm), in the pedipalpal femur length/width ratio (3.90 vs. 3.70– 3.80), in the chelal length/width ratio (3.49 vs. 3.10– 3.33), in the form of the pedipalpal articles (Fig. 1 vs. Fig. 196; Beier 1963), and in the body size (smaller vs. larger). The species R. lubricus L. Koch, 1873, otherwise mentioned for Bosnia and Herzegovina, has been revised and is now known only from western Europe and ´ eastern North America (Curči´ c 1992). Distribution. The specimen studied has been collected under a stone in the completely dark and humid cave canal. Since the new species has no eyes, it should be considered as a typical troglobitic form. Conclusion It is evident that different representatives of Roncus lived or originated in areas and geological epochs with a warm and humid climate (Guéorguiev 1977). With increasing aridity and formation of different niches underground, some species (e.g., Roncus travuniensis sp. n.) evolved as cave inhabitants too. Therefore, adaptation to life in deep soil and in caves is not characteristic of a particular taxonomic group of arachnids, but rather represents an adaptive response of both epigean and humicolous species, including false scorpions, in order to survive in conditions of a typical or modified Mediter´ ranean climate (Curči´ c 1986, 1988). References Beier M. 1932. Pseudoscorpionidea. I. Subordn. Chthoniinea et Neobisiinea. Das Tierreich 57: 1–258. Beier M. 1963. Ordnung Pseudoscorpionidea (Afterskorpione). Bestimmungsbücher zur Bodenfauna Europas, Lieferung 1, Akademie-Verlag, Berlin, 313 pp. ´ Curči´ c B.P.M. 1974. Catalogus Faunae Jugoslaviae, III/4, Arachnoidea. Pseudoscorpiones, Cons. Acad. Sci. Rei Publ. Soc. Foed. Jugosl., Acad. Sci. Art. Slov., Ljubljana, 35 pp.

New troglobitic pseudoscorpion from Bosnia-Herzegovina ´ Curči´ c B.P.M. 1977. Uporedno-morfološka obeležja – njihov značaj i primena u klasifikaciji taksona porodice Neobisiidae (Pseudoscorpiones, Arachnida). PhD. Thesis, Fac. Sci., Univ. Belgrade, Belgrade, 186 pp. ´ Curči´ c B.P.M. 1986. On the origin and biogeography of some pseudoscorpions of the Balkan Peninsula. Biologia GalloHellenica 12: 85–92. ´ Curči´ c B.P.M. 1988. Cave-Dwelling Pseudoscorpions of the Dinaric Karst. Acad. Sci. Art. Slov., Cl. IV, Hist. Nat., Opera 26, Inst. Biol. Ioannis Hadži, 8, Ljubljana, 192 pp.

87 ´ Curči´ c B.P.M. 1992. On the taxonomic position of Roncus lu´ bricus pannonius Curči´ c, Dimitrijevi´c and Karamata, 1992 (Neobisiidae, Pseudoscorpiones, Arachnida). Arch. Biol. Sci., Belgrade 44 (3–4): 25P–26P. Guéorguiev V.B. 1977. La faune troglobie terrestre de la péninsule Balkanique. Origine, formation et zoogéographie. Académie Bulgare des Sciences, Sofia, 182 pp. Harvey M.S. 1990. Catalogue of the Pseudoscorpionida. Manchester University Press, Manchester and New York, 726 pp. Received February 8, 2006 Accepted May 9, 2006