Neobisium radjai n . sp . ( Neobisiidae : Pseudoscorpiones ) , a new cave-dwelling pseudoscorpion from Bosnia and Herzegovina

A new cavernicolous pseudoscorpion species, Neobisium radjai n. sp., from the Golubanјka pećina Cave, village of Srđevići, near Livno, Hercegbosanska ţupanija county, western Bosnia and Herzegovina, is described and compared to its close congeners. The newly erected taxon represents an endemic and a relict form.

Of the seven pseudoscorpion families recorded in Bosnia and Herzegovina (with 58 species), the Neobisiidae family is the most numerous, with 30 species (51.72%).Second most numerous pseudoscorpion family in Bosnia and Herzegovina is the Chthoniidae family, which comprises 17 species (29.31%).Representatives of other pseudoscorpion families are present in considerably smaller number of species and lower percentages (Cheliferidae and Chernetidaeeach with four species or 6.90%, while Garypidae, Olpiidae and Withiidaeeach with one species or 1.72%).
The Chthoniidae family in Bosnia and Herzegovina comprises 17 species, of which 16 ones (94.12%) belong to the genus Chthonius C. L. Koch, 1843, and one species (5.88%) belongs to the genus Troglochthonius Beier, 1939.

Material and Methods
A careful analysis of the collected faunistic material in the Golubanjka Pećina Cave near Livno (western Bosnia and Herzegovina) in 2016 revealed the presence of one specimen of a new pseudoscorpion taxon -Neobisium radjai n. sp.The type specimen was collected by hand.The specimen was carefully dissected, measured and mounted in gum-chloral medium (Swan's fluid) in the laboratory of the Institute of Zoology, University of Belgrade -Faculty of Biology, Belgrade, Serbia.The type specimen is deposited in the collection of the Institute of Zoology, University of Belgrade -Faculty of Biology, Belgrade, Serbia.Drawings were made using a Jenamed 2 light binocular stereomicroscope.The photograph of a female specimen was taken using a Nikon DS-Fi2 camera with a Nikon DS-L3 camera controller attached to a Nikon SMZ1270 binocular stereomicroscope.Final stacking was done using the Zerene Stacker software.The final image was processed with Adobe Photoshop CS6.

Taxonomy
Ordo Pseudoscorpiones Family Neobisiidae Chamberlin, 1930Neobisium Chamberlin, 1930 Neobisium radjai Dimitrijević, n. sp.(Figs.1-9; Table 1) Derivatio nominis.The erected pseudoscorpion species is named after Tonći Rađa, a distinguished Croatian biospeleologist and the president of the Špiljar Speleological Society (Split, Croatia), who collected the type specimen of the new species.Over the last 25 years, Mr. Rađa significantly contributed to the better knowledge of biospeleology in the Balkan Peninsula.
Description.Carapace slightly longer than broad (Table 1; Figs. 1 and 9).Epistome in form of a low hyaline convexity (Fig. 4).No eyes or eye-spots developed.Nineteen setae distributed in four rows on carapax.Carapacal setal formula: 4 + 6 + 5 + 4 = 19.Carapace reticulate.Chelicera 1.88 times as long as broad (Table 1; Fig. 3).Six setae situated on cheliceral palm, whilst one seta borne on movable cheliceral finger.Tubercle of movable cheliceral finger is a low hyaline convexity.Eleven and seven teeth of uneven size and shape present on fixed and movable cheliceral fingers, respectively.Flagellum of 13 blades.Only the two distal most blades pinnated anteriorly.All other blades smooth, acuminate and decrease in size proximally (Fig. 8).
Male genital area: unknown.Manducatory process of pedipalpal coxa bears four setae.All pedipalpal articles smooth and elongate (Figs. 5 and 9).Fixed and movable pedipalpal chelal fingers carry 178 and 145 teeth, respectively.Teeth on movable chelal finger square-topped and close-set in proximal part of the finger, similar in shape and size to teeth on the fixed chelal finger (Fig. 6).Four trichobothria on movable chelal finger and eight trichobothria on fixed the chelal finger.Pedipalpal femur 8.92 times as long as broad (Table 1), considerably longer than carapace.Pedipalpal patella (tibia) 4.79 times as long as broad (Table 1).Leg IV: tibia, basitarsus and telotarsus each carry a single tactile seta (Fig. 7).Sub-terminal tarsal setae furcate; each branch has a few tiny spinules.

Discussion
According to the current knowledge, N. radjai n. sp. is a cave-dweller, an endemic and a relict form populating only its type locality -the Golubanjka Pećina Cave near Livno, western Bosnia and Herzegovina.Like its closest congeners N. davidbengurioni and N. marcchagalli, N. radjai n. sp. is probably a Tertiary form and a descendant of a humicolous and detriticolous pseudoscorpion fauna which inhabited the Balkan Peninsula in the remote past (Ćurčić 1988; Ćurčić et al. 2002).
One more feature is worth mentioning and at the same time intriguing.The number of flagellar blades (13) in the holotype female of N. radjai n. sp. is higher than the number of cheliceral blades recorded in all other known cavernicolous Neobisium spp.which inhabit the Dinaric Karst.Subsequent analysis of male specimens of this species, when obtained, will show whether the recorded number of flagellar blades is a characteristic of the species or is the result of a teratological variation (phenomenon rarely encountered in cave-dwelling pseudoscorpions) (Muchmore 1967;Ćurčić 1988;Dimitrijević 1997).
Erecting a species new to science based on description of a single available specimen is not uncommon (Heurtault 1975;Mahnert 1985;Henderickx & Vets 2000;Muchmore 2000).We can only hope that future investigations in the Golubanjka Pećina Cave will result in obtaining male and subadult specimens of the new species.Such findings will enable to create an additional description of the species and will give better insight into the intraspecific variability.

Conclusions
Of all republics (now separate countries) of the former Socialistic Federative Republic of Yugoslavia, Bosnia and Herzegovina holds third place in the number of recorded pseudoscorpion species.A fairly low number of known pseudoscorpion taxa in Bosnia and Herzegovina (58 species) can be attributed to the facts that there are no native pseudoscorpionologists in the country and no continuous investigations of both epigean and cavernicolous pseudoscorpion fauna are being carried out in Bosnia and Herzegovina.
Bosnia and Herzegovina is rich in caves, pits, ponors and other types of underground habitats, and future investigations will result in increasing the number of the known pseudoscorpion species and will give better insight into diversity of this group of arachnids in this part of the Balkan Peninsula, which has not been in the focus of arachnologists for many years.