A New CAve PseudosCorPioN from the regioN of mANgAliA (romANiA): Chthonius (EphippioChthonius) borisskEti N. sP. (ChthoNiidAe, PseudosCorPioNes)

Only two species of Chthonius (Ephippiochthonius) (Chthoniidae) are presently known from Dobruja, romania. Among these one should mention Chthonius (Ephippiochthonius) tetrachelatus (Preyssler) (not endemic) and C. (E.) scythicus Georgescu & Cãpuşe (endemic). A new cave species belonging to the genus Chthonius — Chthonius (Ephippiochthonius) borissketi Ćurčić and Sarbu n. sp., is described from a well nr. Movile Cave, Mangalia, romania and is endemic to the area studied. Its taxonomic relationships with phenetically close congeners, as well as its comparative morphological traits, are described in detail.


INtrODuCtION
The Dobruja Plateau comprises two distinct parts: the northern part, "root of some very old mountains, heavily eroded to the dimensions of mere hills, and the southern part, of lower altitude and more even relief " (Ćurčić andDecu, 2004-2005).The Southern Dobruja tableland is lower and comprised of rocks that are an integral part of the pre-Balkan Platform.The superficial geological formation (Sarmatian sediments with predominating limestone and covering layer of loess) is tabularly arranged, accounting for the monotonous relief forms, canyon-like valleys, the depressions of the Negru vodã tableland, as well as for the cliffs of the Black Sea coast and the steep bank of the Danube river.In general, the altitude of this tableland does not rise above 200 m.
The Southern Dobruja region (southwestern romania) provides the ideal locality for examining sulphidic locations, as it has a sulphidic aquifer that can be accessed through artificial wells, springs and the Movile Cave.Discovered in 1986, Movile Cave was the first terrestrial chemoautotrophic ecosystem described (Sarbu and Popa 1992;Sarbu et al. 1996;Sarbu 2000;Flot et al. 2013) and is one of the most thoroughly studied to date.It harbors eight pseudoscorpion species (Ćurčić andDecu 2004-2005)

description:
The carapace is longer than broad, and its anterior border is wider than the posterior border (Fig. 4, table 1).The anterior eyes (with flat lenses) are distant and lie about a diameter from the anterior carapacal border.The posterior eyes are small, eyespot-like, and are removed by about half a distance from the anterior eyes (Fig. 4).The anterior border carries no differentiated epistome, although there are tiny denticulations, particularly between two anterior and median setae (Fig. 4).
The number of setae carried on the abdominal tergites I -X of the holotype male can be expressed as 2 -4 -4 -4 -6 -6 -6 -6 -6 -6.The sternite II of the male carries 12 small setae.The following sternite is deeply grooved in the form of v and on its interior face carries 14 (7 + 7) setae (Fig. 7).In addition, there is a transverse row of 10 setae on the posterior border of this sternite, the median pair of which are placed at the base of a v-shaped opening; anterior to each stigma, there are three microsetae.Sternite Iv has 10 posterior setae and 2 suprastigmatic microsetae on either side.Sternite v carries 8 marginal setae, sternite vI -6, sternite vII -6, sternite vIII -6, sternite IX -6, and sternite X -6 posterior setae.The male carries two pairs of small setae on the twelfth abdominal segment.
Female genital area: unknown.
The cheliceral spinneret (galea) is not distinctive (Fig. 3).There seems to be no isolated tooth on the movable cheliceral finger.The first large tooth is contiguous with a series of smaller teeth that end below the insertion site of the galeal seta (gl).On the fixed finger, the teeth extend slightly back, diminishing in size, below those on the movable finger (Fig. 3).
The movable cheliceral finger carries one large seta and five or six long setae on the palm of the chelicera.In addition, two small accessory setae are carried exterior to vb.The movable finger is longer than the cheliceral breadth and the ratio of chelal length to breadth is 1.85 (table 1).The flagellum consists of nine blades.The most distal members of the series are curved, but all, to some extent, are pinnate on two sides.
The coxae of the pedipalps each carry six setae: three at the anterior end and three on the posterior border of the trochantic foramen.The femur is 5.67 times longer than its breadth and 1.34 times longer than the carapace (table 1).The patella is tulip-like and its distal end is slightly broader than the pedipalpal femur (Fig. 3).
Four trichobothria are carried on the movable and eight on the fixed pedipalpal chelal fingers (Figs. 1 and 2).The contour of the chelal palm on the dorsal side is depressed in front of trichobothria ib and isb.The teeth of the fixed finger ( 17) are distributed evenly along its inner length; these are triangular and interspaced.The movable finger has 12 teeth that resemble the dentition of the fixed finger.Proximally, the teeth decrease in size until the last six are small eruptions at the base of the finger (Fig. 1).The movable finger has a pronounced apodeme.
The measurements of the different podomeres of the leg Iv, as well as the tactile setae ratios, are presented in table 1. tibia Iv, metatarsus Iv, and tarsus Iv each carry a long tactile seta (Fig. 6, table 1).The claws are slender, smooth and sickle-shaped.differential diagnosis: From its phonetically closest congener, Chthonius (Ephippiochthonius) scythicus, the new species differs in many important respects: in the shape of all appendages, in body size, pedipalpal dentition, number of coxal spines, tergal and sternal setation, as well as in numerous morphometric ratios and linear measurements of various structures.

remarks:
The diversity of the pseudoscorpions analyzed precludes a simplified treatment of its ecology.we are still discovering and establishing, as in this paper, a number of microhabitats of soil pseudoscorpions in these ecosystems (Ćurčić 1988, 2013; Ćurčić et al. 1993, 2004, 2012a, b, c, d, e, f, g, h, i, j, 2013a, b, c, d, e, f, g, h, 2014a, b, c, d; hadži 1937).The mechanisms of habitat separation are many and different.The diversity of the pseudoscorpions of the soil fauna can be viewed as the totality of the various effects, although it is clear that the indicated effects operate more restrictively and selectively on the level of individual populations.
The type locality of C. (E.) borissketi n. sp.(well Mecu # 31) is found approximately 1.3 km to the east of the Movile Cave, in Mangalia.This particular well is about 14 m deep.The first 6 meters were dug through soil and quaternary deposits.From -6 m to the water level, the well passes through Sarmatian limestone (12 My).
The pseudoscorpion sample was collected at the bottom of the Mecu # 31 well, at about 50 cm above the water surface, from a rock ledge covered with clay.just above the water surface, the limestones are well fractured and show signs of karstic dissolution, similar to the walls of the Movile Cave at the water level.Small cave-like passages are visible but they are too small to be explored.however, it is very likely that these fractures and small passages are connected to other spaces within the limestones forming a network that may be very extensive.Similar karstification can be seen in several other old wells in Mangalia and we assume that some of these wells are interconnected and the terrestrial fauna can thus move between wells.Presumably in these passages, conditions similar to Movile Cave should be found, where the fauna finds a rich supply of food produced by chemoautotrophic sulfur and methane-oxidizing bacteria (Serban pers.comm.).
Dumitrescu & Orghidan, occur in wells, springs, and caves in the surrounding area.Our aims in this study were to (i) characterize the newly discovered pseudoscorpion and (ii) compare it phenetically with its close congeners.The new species described in this paper is an ancient endemic form inhabiting a well close to the Movile Cave (Dobruja) in southeastern romania.etymology: After Academician Boris Sket, Ljubljana (Slovenia) in honour of his great achievements in the field of world biospeleology.material examined: holotype male, from the well Mecu # 51, nr.Mangalia, romania, collected by one of us (SMS) on May 2013.