A new epigean pseudoscorpion species (Pseudoscorpiones: Neobisiidae) from northeast of Iran, with an identification key to the species of the family Neobisiidae from Iran

Zahra LATIFI, Mahrad NASSIRKHANI, Omid MIRSHAMSI* Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran Entomology Department, Faculty of Agriculture and Natural Resources, Islamic Azad University, Arak branch, Arak, Iran Reseach Department of Zoological Innovations (RDZI), Institute of Applied Zoology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran


Introduction
The genus Roncus L. Koch, 1873 belonging to the family Neobisiidae Chamberlin, 1930 currently contains 127 described species. Little is known about the Roncus species distributed in western Asia and there are no detailed description/redescription of them (Nassirkhani and Mumladze, 2019). Therefore, it is not possible to compare some diagnostic characteristics for all of the species, e.g., the presence/absence of the microsetae located proximal to the trichobothria eb and esb, or number of microsetae between the trichobothria eb and esb. These characters have been repeatedly used to separate the species by some authors such as Gardini (1983), Gardini and Rizzerio (1985), Hendericks and Zaragoza (2000), Zaragoza and Šťáhlavský (2008), and Zaragoza and Hendericks (2009). Nassirkhani and Mumladze (2019) provided a key to the Roncus species recorded for the Middle East and Caucasian regions based on the morphological and morphometric characteristics presented in the literature. However, reexamination of these species seems to be mandatory.
The diversity of the Pseudoscorpiones is not well known for Iran, one of the largest countries in the Middle East. Though 65 valid pseudoscorpion species (belonging to 32 genera of 12 families) were recorded from Iran, studies are relatively scarce and scattered as the new species/records Swann᾿s medium (fluid), and studied and illustrated with an Olympus CH-2 compound microscope equipped with a drawing tube.
The morphological nomenclatures and measurements were adapted from Chamberlin (1931), Harvey (1992), Harvey (2013), Harvey et al. (2012), Judson (2007), and Zaragoza (2017). The depository of the studied material is the Zoological Museum of the Ferdowsi University of Mashhad, Iran (ZMFUM), and the Collection of Acarology Laboratory, Islamic Azad University of Arak, Iran (IAUA). All measurements are in millimeters and measured with Nikon MM-40 measuring microscope.

Etymology
The specific epithet is derived from the type locality.

Diagnosis
Roncus khorasanicus sp. n. differs from the other congeners by the following combination of characters: carapace with two small corneate eyes, transverse furrows absent, epistome long, knob-like and apically rounded, pedipalpl femur and chelal hand slightly granulated, pedipalpal femur with one tubercle on retrolateral and two tubercles on prolateral margin, chelal hand more or less rounded in dorsal view, microsetae proximal to trichobothria eb-esb absent, two short setae located between trichobothria eb and esb, movable chelal finger distinctly longer than chelal hand (with pedicel) and pedipalpal femur, trichobothrium ist located proximed to middle, claws simple and without dorsal tooth, and morphometric characteristics, e.g., pedipalpal femur 0.60-0.65 mm long and 3.52-3.61× longer than broad, and chela (with pedicel) 1.07-1.18 mm long and 3.45-3.68× longer than broad.
Pedipalps: brown, chela slightly darker in color than femur and patella; dorsal surface of trochanter finely granulated, prolateral half of femur distinctly granulated, patella entirely smooth, distal half of chelal hand distinctly granulated at base of fixed finger ( Figure  2E); coxa including manducatory process with 11 setae, manducatory process with five acuminate setae, seta located at base of manducatory process longest; trochanter with small dorsal tubercle, L/W 2.10-2.22; femur with short pedicel, prolateral margin with two tubercles located in basal half of the segment, one tubercle located medially on retrolateral margin, with one glandular pore located distally, with a number of long setae without enlarged alveoli in basal two thirds of the segment ( Figure 2E), L/W 3.52-3.61; patella with short and stout pedicel (L=0.16-0.18 mm); patella distinctly shorter than femur, with three lyrifissures situated basally and two lyrifissures located distally, L/W 2.47-2.50; chela (with pedicel) L/W 3.45-3.68; chela (without pedicel) L/W 3.13-3.37; chelal setae simple; movable finger distinctly longer than hand (with pedicel); movable finger 1.54-1.60× longer than hand (with pedicel); chelal hand more or less rounded in dorsal view ( Figure 2E); hand (with pedicel) L/W 1.55-1.67; true microsetae on chelal fingers absent; two short setae situated between eb and esb in lateral view, short setae/microsetae proximal to trichobothria eb and esb absent; fixed finger with three lyrifissures: one (fa) located at same level of esb and one (fb) at same level of isb in retrolateral view, and one (fd) at same level of et in dorsal view; movable finger with three lyrifissures in lateral view: one (ma 2 ) located slightly distal of b, one (ma 1 ) between trichobothria sb and st, and one (ma 3 ) between st and t; chelal hand with one lyrifissure (hp) located close to pedicel and one glandular pore located distally in retrolateral view; two sensilla present, one sensillum located close to dental margin, approximately in the middle of distance between sb and st, and other sensillum situated slightly distal to sb; fixed finger with 59-62 similar contiguous teeth, reaching slightly distal of trichobothrium ib, all teeth with dental canal; movable finger with 51-54 contiguous teeth, not reaching to the level of trichobothrium b, distal teeth cusped and large, gradually reduced in size, basal teeth flattened but distinguishable, all teeth with dental canals; nodus ramosus of venom duct in fixed chelal finger situated distinctly distal to et.
Trichobothriotaxy: fixed finger with 8 and movable finger with 4 trichobothria; fixed finger with trichobothrium it located in the middle of et and est, ist situated distad to middle of the finger (TS=0.55-0.57), ist distinctly closer to it than to ib, isb on retrolateral face, ib situated basally closer to esb than to isb, eb and esb located basally; movable finger with trichobothrium st situated distinctly closer to t than to sb, sb distinctly situated in midway between b and st; distance b-sb longer than distance t-st ( Figure 2F).

Remarks
According to the identification key provided by Nassirkhani and Mumladze (2019) and the description provided by Mahnert (1974) R. khorasanicus sp. n. resembles most closely to R. viti. Due attention to the presence of two small corneate eyes, the chaetatoxay of the carapace and the tergite I (posterior margin of carapace and tergite I with six setae), the presence of a small tubercle on dorsal surface of the trochanter, loss of microsetae located proximal to trichobothria eb and esb (judging from Mahnert 1974), the granulation pattern of the pedipalp (i.e. femur clearly granulate, patella entirely smooth, dorsal and mediolateral face of chela hand granulated) (see Mahnert, 1974), the more or less rounded shape of the chela hand in dorsal view (see Mahnert, 1974), the trichobothriotaxy especially the position of trichobothrium ist on the fixed chela finger, and the morphometric characteristics, e.g., the movable chela finger distinctly longer than the chela hand (with pedicel) (ratio > 1.5×) and somewhat longer than the femur, and length of the pedipalpal femur (Length < 1.00 mm), the new species, R. khorasanicus sp. n., from northeastern part of Iran resembles R. viti which was originally described from Guilan province, northern Iran by Mahnert (1974).
Comparatively, the prolateral and retrolateral margins of the pedipalpal femur of R. viti bear no tubercles (see Mahnert, 1974) whereas in R. khorasanicus sp. n., there are two tubercles on the prolateral and one tubercle on the retrolateral margin of the pediplapal femur. This is the most important difference between these two species. Moreover, the posterior transverse furrow on the carapace of R. viti is present (see Mahnert, 1974), while both transverse furrows are completely absent in R. khorasanicus sp. n.
Also, these two species can be separated from each other on the basis of some morphometric characteristics (Table), e.g., the pedipalp femur of R. viti is 3.9× longer than wide whereas it is 3.5-3.6× longer than wide in R. khorasanicus sp. n. (Figure 3). The size of epistome is the minor difference between the species, e.g., the carapace of R. viti has a smaller epistome than that of R. khorasanicus sp. n. (see Mahnert, 1974).

Female: Unknown Key to the species of the family Neobisiidae from Iran
A total of 13 species belonging to the Neobisiidae family have been up to now recorded from Iran, The present key is prepared on the basis of the morphological and morphometric characters mentioned in the literature and can be used for recognizing the adult stage of the family from Iran.  (Beier, 1971) (Mazandaran Province)