Description of two new species and redescription of one species of agnarid terrestrial isopods (Oniscidea, Agnaridae) from western Iran

Abstract The present study reports on three species of terrestrial isopods from western Iran. The genus Mongoloniscus Verhoeff, 1930 is recorded for the first time from Iran, with description of a new species: M. persicus sp. n. Protracheoniscus ehsani sp. n. is described and P. darevskii Borutzky, 1975 is redescribed based on Iranian specimens. The diagnostic characters of these species are figured and their geographical distribution is presented on a map.


Introduction
The terrestrial isopods of the family Agnaridae Schmidt, 2003 are distributed from the Mediterranean region to eastern and southern Asia (Schmidt 2003(Schmidt , 2008. The German author postulated an Indian origin for the family. He considered the internal lungs with spiracles located on the lateral margin of all pleopod exopodites as the only autapomorphy of the family. According to world catalogue of terrestrial isopods (Schmalfuss 2003), Agnaridae include 15 nominal genera. Former studies recorded two genera in Iran: Hemilepistus Budde-Lund, 1879and Protracheoniscus Verhoeff, 1917(Kashani et al. 2010, Kashani 2014. In this study, three agnarid species are reported from western Iran, of which two are new species. The genus Mongoloniscus is found for the first time in Iran. Protracheoniscus darevskii Borutzky, 1975 is reported for the first time from Iran. Since the type specimens are lost, a redescription of the species is presented based on Iranian specimens. Moreover, two new species, namely Mongoloniscus persicus sp. n. and Protracheoniscus ehsani sp. n. are described. Sampling localities for these species are presented on the map (Fig. 1).

Material and methods
The material examined was collected in many localities from western Iran (Fig 1). Specimens were collected by hand and preserved in 96% ethanol. The isopods were dissected and body parts were slide-mounted in Euparal. Drawings were made using a drawing tube fitted on a SaIran ZSM-100 dissecting stereomicroscope and on a Nikon Y-IDT compound microscope. Type material of the newly described species is deposited in the Zoological Museum, University of Tehran (ZUTC), Staatliches Museum für Naturkunde, Stuttgart (SMNS), Iranian Research Institute of Plant Protection (IRIPP) and in the author personal collection (PCGMK). All the other specimens are kept in PCGMK. Diagnosis. Kwon (1993) discussed in details the characteristics of the genus Mongoloniscus and considered it as a good genus. He mentioned the granulated dorsum and triangular median lobe of the head as differentiating characters of the genus from Protracheoniscus. According to the eco-morphological classification proposed by Schmalfuss (1984), the members of the genus are clinger type. Diagnosis. Head with well developed lateral and median lobes. Male pereopod VII ischium with concave ventral margin. Male pleopod exopodite I with a deep hollow at apex.

Mongoloniscus persicus
Description. Maximum length, male and female, 6 mm. Color pale brown with the usual pale muscles spots. Body outline as in Fig. 2A. Cephalon with well developed lateral and median lobes; frons with an incision in the middle, vertex with faint tubercles (Fig. 2B). Antenna surpassing the posterior margin of pereon-tergite I but not reaching the posterior margin of pereon-tergite II; fifth article of peduncle as long as flagellum, with length:width ratio 4:1; flagellum with two articles, proximal one shorter, flagellar articles ratio 1:1.5 (Fig. 2D). Pereon covered with faint tubercles. Pereon-tergite I with rounded posterolateral margin. Noduli laterales on pereonites II to IV distinctly more distant from the lateral margins than those on pereonites I and V to VII ( Fig. 2A).
Male: Pereopods I-III merus and carpus with brushes of trifid setae (Fig. 2E). Pereopod I ischium triangular, carpus with depression on rostral surface equipped with slender scales; propodus narrow and long, proximal part of sternal margin with dense small scales, distal part bearing strong setae; dactylus with one dactylar and one ungual seta (Fig. 2E). Pereopod VII ischium with concave ventral margin, straight in smaller specimens; propodus narrow and long; dactylus with one dactylar and one ungual seta (Fig. 2F). Pleopod exopodite I with long hind lobe bearing a deep hollow and one short seta at apex, outer margin with no setae (Fig. 3B); endopodite I straight with triangular apical part slightly bent outwards and some short setae (Fig.  3A). Pleopod endopodite II longer than exopodite; exopodite triangular with a line of strong setae on outer margin (Fig. 3C). Pleopod exopodites III-V as in Fig. 3D-F. Etymology. Due to the broad geographical distribution of the species in Iran, the name of the species is after the old name of the country, Persia.
Remarks. Prior to this study, the genus Mongoloniscus was only reported from eastern Asia (Kwon 1993;Schmalfuss 2003). Mongoloniscus persicus sp. n. is the first species of the genus Mongoloniscus to be reported from western Asia. It has a broad geographical distribution in the central and western parts of Iran. Ecologically, this species is well adapted to cultivated areas and exists in huge numbers in some habitats.

Genus Protracheoniscus Verhoeff, 1917
Diagnosis. Body length variable, up to 25 mm; tergites always smooth; head with short or developed lateral lobes; antenna variable in size, with flagellum of two articles; pereon epimera I with rounded posterolateral corner; telson triangular with more or less concave sides; male pleopod exopodite I with short to long hind lobe, endopodite I straight; clinger or runner type according to the eco-morphological classification proposed by Schmalfuss (1984). Redescription. Maximum length, male and female, 10 mm. Color dark brown with the usual pale muscles spots. Body outline as in Fig. 4A. Cephalon with rounded lateral lobes not protruding compared with broadly rounded frons (Fig. 4B). Antenna long, surpassing the posterior margin of pereon-tergite III; fifth article of peduncle as long as flagellum, with length:width ratio 7:1; flagellum with two articles, proximal article as long as the distal one (Fig. 4D).

Protracheoniscus darevskii
Pereon smooth. Pereon-tergite I with rounded posterolateral margin. Noduli laterales on pereonites I to IV distinctly more distant from the lateral margins than those on pereonites V to VII (Fig. 4A).
Male: Pereopods I-III merus and carpus with brushes of setae (Fig. 4E). Pereopod I ischium triangular, carpus with depression on rostral surface equipped with slender scales; propodus narrow and long, proximal part of sternal margin with dense small scales, distal part bearing strong setae; dactylus with one dactylar and one ungual seta (Fig. 4E). Pereopod VII ischium with straight or concave ventral margin, merus with a short crest on dorsal margin, propodus narrow and long, dactylus with one dactylar and one ungual seta (Fig. 4F, G). Pleopod exopodite I with long hind lobe bearing a deep hollow at apex, in smaller specimens with an obliquely truncate apex; outer margin with several spine setae (Fig. 5B-D); endopodite I straight with an apical lobe equipped with small setae (Fig. 5A). Pleopod endopodite II longer than exopodite; exopodite triangular with a line of strong setae on outer margin (Fig. 5E). Pleopod exopodites III-V as in Fig. 5F-H.
Remarks. During the examination of type material of terrestrial isopods deposited in Zoological Museum of Moscow State University (ZMMU), it was revealed that the type material of P. darevskii is possibly lost. Borutzky (1975) described the species from Armenia and figured its diagnostic characters. Protracheoniscus darevskii is here redescribed on the new material from western Iran (Fig. 1).
This species is characterized by the male pleopod exopodite I possessing a deep hollow at apical part of distal margin and endopodite I with an apical lobe bearing small setae.
Distribution. Southern Armenia: Megri District; western Iran. Description. Maximum length, male 8 mm and female 11 mm. Color dark brown with the usual pale muscles spots. Body outline as in Fig. 6A. Cephalon with very small lateral lobes not protruding compared with broadly rounded frons (Fig. 6B). Antenna long, surpassing the posterior margin of pereon tergite III; fifth article of peduncle as long as flagellum, with length:width ratio 7:1; flagellum with two articles, proximal article as long as the distal one (Fig. 6D).
Pereon smooth. Pereon tergite I with rounded posterolateral margin. Noduli laterales on pereonites I to IV distinctly more distant from the lateral margins than those on pereonites V to VII (Fig. 6A).
Male: Pereopods I-III merus and carpus with brushes of setae (Fig. 6E). Pereopod I ischium triangular, carpus with depression on rostral surface equipped with slender scales; propodus narrow and long, proximal part of sternal margin concave with dense small scales, distal part bearing strong setae; dactylus with one dactylar and one ungual seta (Fig. 6E). Pereopod VII ischium with concave ventral margin, carpus with a triangle ridge in dorsal margin, propodus narrow and long, dactylus with one dactylar and one ungual seta (Fig. 6F,G). Pleopod exopodite I hind lobe variable in shape, with rounded short to truncate long distal margin; outer margin equipped with few to several strong setae (Fig. 7B-E); endopodite I straight with apical part slightly bent inwards bearing two rows of long setae (Fig. 7A). Pleopod endopodite II longer than exopodite; exopodite triangular, outer margin convex equipped with a line of strong setae (Fig. 7F). Pleopod exopodites III-V as in Fig. 7G-I.
Etymology. The name of the species is after my late friend, Ehsan Entezari, who unfortunately passed away tragically during a field study.
Remarks. Protracheoniscus ehsani sp. n. is characterized by short lateral lobes of head, a triangle ridge on dorsal margin of male pereopod VII carpus, and two rows of long setae at apical part of male pleopod endopodite I. This species is similar to P. darevskii, but differs from that in the shape of pleopod endopodite and exopodite I, and in the conspicuous ridge on the dorsal margin of carpus of pereopod VII.
Distribution. Central Iran.