Kut gen. nov., a new troglomorphic spider genus from Turkey (Araneae, Dysderidae)

A new genus of troglomorphic Dysderidae is described, based mainly on the morphology of copulatory organs. The new genus Kut gen. nov., with the type species Harpactocrates troglophilus Brignoli, 1978, also includes two recently discovered new species from the coastal Mediterranean Turkey: Kut izmiricus sp. nov. and K. dimensis sp. nov. All three species display troglomorphic traits, most distinct in K. dimensis sp. nov. Another genus-level trait is a characteristic simple type of bulb in males. Female copulatory organ shows similarity to the endemic Caucasian genus Cryptoparachtes Dunin, 1992 in paraspermatheca structure, whereas the male copulatory organ is unique among all known Dysderidae.


Introduction
Dysderinae is one of the three subfamilies of the spider family Dysderidae, along with Harpacteinae and Rhodinae. Its members can be clearly distinguished by the unique morphology of sternum and labium joints, as well as by having claw tufts of setae on all tarsi and scopulae on posterior metatarsi (Deeleman-Reinhold and Deeleman 1988).
Digital images of the left palp and vulva were taken with a Leica DFC295 digital camera attached to a Leica S8AP0 stereomicroscope. Five to 30 photographs were taken in different focal planes and combined using COMBINE ZP image stacking software. Photographic images were edited using ADOBE PHOTOSHOP CS6 and COREL-DRAW HOME & STUDENT SUITE X7 was used to create the plates. All measurements are in mm. Terminology for the body parts and copulatory organ structures follows Deeleman- Reinhold and Deeleman (1988) and Chatzaki and Arnedo (2006).
A key to the genera of Dysderinae  Brignoli, 1978. Derivatio nominis. "Kut" is a Turkish word traceable to the old Turkic language with multiple meanings, such as "fortune (good or bad)", "lifelong energy" or "vigour", and more, depending on a dialect or a historical period. Gender: masculine.
Diagnosis. The new genus resembles genera Dysderocrates, Harpactocrates and Hygrocrates in the general morphology of the male palp; however, it can be identified by the following characters: In male copulatory organ of Kut gen. nov., tegulum is pear-shaped and embolus is a simple extension of a tegulum. Embolus represents the only distal extension of tegulum, any other apophyses are absent, unlike in Dysderocrates and Hygrocrates.
In Kut gen. nov., female copulatory organ is unique among the majority of Dysderinae genera in having the anteriorly located, club-shaped spermathecae, bearing a resemblance to those in Cryptoparachtes. Kut gen. nov. differs from Cryptoparachtes by having a well-developed dorsal arc and a distinct posterior diverticulum, as well as by the male copulatory organ (see Dunin 1992: 42).
Anterior side of sternum (the side touching labium) is much more convex compared to other Dysderinae genera.
Description. Large-sized Dysderinae spiders. Somatic characters as in other Dysderidae. Detailed description see under Kut troglophilus (Brignoli, 1978) comb. nov. (Brignoli, 1978) comb. nov. Figure 1 Harpactocrates troglophilus; Brignoli, 1978: 38, f. 4-5 (D♂). Diagnosis. The simple structure of male palp in Kut troglophilus (Brignoli, 1978) is similar to that in some species of Harpactocrates, Harpactea, Parachtes, and Stalagtia. In K. troglophilus palp, the bulb gradually gets thinner and eventually gives rise to embolus, with a transition between tegulum and embolus rather indistinct, unlike in the other genera. Another unique feature of this genus is that the tip of the embolus is continuously bent posteriorly. In females, K. troglophilus vulva resembles that of the Caucasian genus Cryptoparachtes; however, in all three species of the latter (C. adzharicus, C. charitonowi and C. fedotovi), spermathecae are club-shaped. Paraspermatheca is distally spherical in all species of Cryptoparachtes, whereas in K. troglophilus paraspermathecae club shaped and more or less of equal length like the midspermatheca, unlike in three Cryptoparachtes species mentioned.
Description. Carapace hexagonal, reddish brown, with a smooth surface. Cephalic region darker than the thoracic region (Fig. 1A). Eyes reduced. Posterior eyes approximately of the same diameter and aligned. Posterior median eyes adjacent, as distant as their diameter to posterior lateral eyes. Chelicera robust, dark brown ( Fig. 1B, C). Cheliceral groove with four teeth, two on pro-and two on retromargin. Among retromarginal teeth, proximal one smaller, distant one larger. Promarginal teeth approximately of the same size, proximal one in alignment with the proximal one of the retromargin.  (Brignoli, 1978) comb. nov. A carapace B chelicerae C prosoma D male palp, retrolateral view E ditto, prolateral view F ditto, nearly retrolateral view G vulva, dorsal view H ditto, ventral view. Scale bars: 0.5 (D), 0.125 (G).
Labium and gnathocoxae brown. Anterior sides of gnathocoxae chitinized at borders and dark brown. Labium anteriorly with a V-shaped incision. Sternum yellowish brown. Anterior side of sternum (touching labium) slightly convex (Fig. 1C).
Legs yellowish, light brown. Leg coxa, trochanter, and femora darker in colour at joints. Femora and tibiae I and II prolaterally with spines; number of spines variable among individual spiders. Tibiae I and II with ventral spines. See Tables 1, 2 for details on leg measurements and spination. Abdomen long and slender, greyish cream in colour.
Palp (Fig. 1D-F). Palpal tarsus shorter than tibia, conical. Tarsus and tibia lighter in colour compared to other palp segments. Tegulum cylindrical; embolus originates from the anterior dorsal side of tegulum and is bent posteriorly as an arc. Tegulum and embolus distinctly different in colour.
Vulva (Fig. 1G, H). Midspermatheca club-shaped. Paraspermathecae pin-shaped and similar in size to midspermatheca. Spermathecae surrounded by a dome-shaped chitinized structure. Spermathecae posteriorly with two horizontally aligned bars of equal sizes; of these, one closer to spermathecae is less chitinized than the other.
Note. Brignoli (1978) described Harpactocrates troglophilus based on two adult males collected from the Zindan Cave (Isparta Province, Turkey). He also recorded (marked as "cf.") additional juvenile specimens from three other localities (all from caves), at the close vicinity of the type locality. Our specimens of Kut troglophilus (Brignoli, 1978) comb. nov. were collected from one of these localities, Kurucaova Village (Konya Province), close to the İnönü Cave, by both pitfall and MSS traps.    (Brignoli, 1978) comb. nov (♂/♀). Derivatio nominis. The specific name is a toponym that refers to the type locality, İzmir Province.
Description. Carapace reddish brown, with thick dark brown contours at the borders. Fovea distinct, longitudinal ( Fig. 2A). Carapace surface with tiny dents; these dents with tiny, black setae inside. These setae are longer in the cephalic region, especially around eyes. Eyes tiny, reduced. Distance between anterior eyes approximately 2.5 times their diameter. Posterior eyes spherical, slightly concave. Chelicera, gnathocoxa, and labium dark brown. The new species resembles K. troglophilus by the other cheliceral traits (Fig. 2B). Sternum brown, covered with setae, and with dark brown contours at the borders. Sternum with eight dark brown blotches, symmetrically reaching from sides toward center. Gnathocoxae with yellowish setae prolaterally at tips (Fig. 2B, C).   Tables 3, 4 for details on leg measurements and spination. Abdomen slender, cylindrical, greyish cream in colour.
Palp (Figs 2D-F). Palpal tarsus shorter than tibia, conical. Tegulum exceeds embolus in length. First half of tegulum cylindrical, second half reversely conical. The anterior side of the tegulum smoothly straight. Embolus short and hookshaped, bent posteriorly. Vulva (Fig. 2G, H). Midspermatheca club shaped, very long, its tip transparent and slightly bent posteriorly. Paraspermathecae short, spherical. Posteriorly to spermathecae, two horizontally aligned bars; among these, one closer to spermathecae is shorter, distant one twice as long and more chitinized. Diagnosis. Male palp of Kut dimensis sp. nov. closely resembles that of K. troglophilus (Brignoli, 1978) comb. nov. Kut dimensis sp. nov. palp differs by having an embolus with tip sharply bent posteriorly, instead of gradually, and by having a more slender tegulum. Difference between Kut dimensis sp. nov. and K. izmiricus sp. nov. palps is more distinct, since in K. izmiricus sp. nov. tegulum/embolus ratio is higher  compared to other species of the genus. K. dimensis sp. nov. females differ from other species by having longer paraspermathecae compared to midspermathecae, which is the opposite in the other two species. Description. Somatic traits of Kut dimensis sp. nov. resemble the other two species in general. Eye reduction at an extreme level, eyes almost absent (Fig. 4A). Anterior and posteriolateral eyes barely visible only under stereomicroscope, in a state of indistinct spots. Legs more slender than in K. troglophilus (Brignoli, 1978) comb. nov. Anterior metatarsi with ventral spines. See Tables 5, 6 for details on leg measurements and spination.
Palp (Fig. 4G, H). Palpal tarsus shorter than tibia, conical. ¾ part of embolus continues straight after the separation from the tegulum, then bent with a sharp coil at the 4 th quarter, shaped like an "L" towards posterior.
Note. Kut dimensis sp. nov. is not the first troglomorphic species recorded from its type locality, the Dim Cave. López-Pancorbo et al. (2013)    Province". We provide these details to point out that Kut dimensis sp. nov. has not been found outside of the cave, in surface habitats, despite extensive sampling efforts, which is one of the reasons we consider this species a troglobiont.

Discussion
With the description of Kut gen. nov., the number of genera belonging to spider family Dysderidae is now 25. Even though there are other genera known exclusively from hypogean habitats such as caves (for example Minotauria Kulczyński, 1903 andFolkia Kratochvil, 1970 from Harpacteinae; Stalita Schiödte, 1847 from Rhodinae), Kut gen. nov. is the first genus of Dysderidae ever discovered, in which all known species display troglomorphic traits such as reduced eyes or hypogean foraging. Kut troglophilus (Brignoli, 1978) is currently the only species of the Kut gen. nov. with recorded surface activity; however, it was also recorded from hypogean habitats: in MSS with this study and the Zindan Cave (Brignoli 1978). The other two species were recorded either exclusively from caves (Kut dimensis sp. nov.) or from MSS (Kut izmiricus sp. nov.) (Fig. 5).
With this paper, we have resolved the discussion regarding the generic placement of Kut troglophilus. In our opinion, Kut gen. nov. has a unique and important position among Dysderidae due to its troglobitic and biogeographic affinities, coupled with the unique morphology of copulatory organs.
During our sampling efforts throughout the Mediterranean Turkey by using MSS traps, we have discovered further populations that might very likely belong to Kut gen. nov. as well. Moreover, we have collected subadult individuals from central parts of Anatolia with similar morphology, which may indicate a more or less continuous range of the genus throughout the Anatolia. We hope to reveal the specific identity of these populations, study their relationship to the known Aegean, Mediterranean, and Central Anatolian species, and the relationship between Kut gen. nov. and the Caucasian Cryptoparachtes in the near future. A high level of endemicity of Dysderinae around Anatolia at both species and genus levels indicates that many more taxa are still waiting to be discovered.