A male of Stenochilus (Stenochilidae) is reported from southern Iraq, representing the first record of the family for the Middle East and the westernmost record of the family. The specimen was identified as Stenochilus hobsoni O. , previously known only from India.
Stenochilidae Thorell, 1873 is one of the smallest families within Araneomorphae, represented by 13 species belonging to two genera (World Spider Catalog 2021) and distributed in the Oriental Realm from India to Fiji (Zheng et al. 2009). Members of this family are characterized by their uniquely diamond-shaped prosoma with fovea constricted in the middle, four posterior spinneret remnants and divided prolateral scopulae on metatarsi I and II. The genus Stenochilus O. Pickard-Cambridge, 1871 can be recognized by the laterally undulating margins of the prosoma, presence of an embolus and accessory sclerites on the palps and by unpaired median spermathecae in the internal female genitalia (Platnick & Shadab 1974). The genus comprises three species, which are known from a few Southeast Asian countries: India, Sri Lanka, Myanmar and Cambodia (World Spider Catalog 2021).
While studying newly collected material from Dhi Qar Province in southern Iraq, specimens belonging to Stenochilus O. Pickard-Cambridge, 1871 were found. They were identified as S. hobsoni O. Pickard-Cambridge, 1871, which was previously only known from India (World Spider Catalog 2021). Generally, the spider fauna of Iraq is still poorly known. In recent years a compilation of the known species (Zamani & El-Hennawy 2016) and several other papers on Iraqi spiders were published (Fomichev et al. 2018, Al-Khazali 2018, 2020, Al-Khazali & Najim 2018, Al-Khazali & Jäger 2019). The last five of these articles deal with spiders found in the Dhi Qar province, in which Stenochilus was now found.
Material and methods
The spiders were collected manually from under dry mud piles located on the bank of an irrigation canal embedded in agricultural land. The specimens are deposited at the College of Basic Education, University of Sumer, Dhi Qar, Iraq. For the photos a Nikon D750, D5600 camera on an EZ4 stereo-microscope has been used. Photographs of the pedipalp were taken in a dish with white cotton at the bottom, filled with alcohol. Digital images were stacked using the Image focus program Zerene Stacker. Leg measurements are provided as totals (without coxa) (femur, patella, tibia, metatarsus, tarsus). All measurements are in mm.
Taxonomy
Family Stenochilidae Thorell, 1873
Stenochilus hobsoni O. Pickard-Cambridge 1871 (Figs 1-2)
For taxonomic references see the World Spider Catalog (2021).
Specimens examined. Southern IRAQ, Dhi Qar Province, Qalht Suker district, agricultural land, under dry mud piles, 31.85732°N, 46.08153°E, 12 m a.s.l. (Fig. 3), 10. Mar. 2020, 1 ♂ and 1 subadult ♂, leg. A. M. Al-Khazali.
Determination. Platnick & Shadab (1974).
Description of male. General appearance as in Fig. 1a, b. Measurements: Body length 5.54; prosoma 2.69 long, 1.26 wide; opisthosoma 2.85 long, 1.34 wide. Femur I 1.44 long. Leg measurements: I 4.43 (1.44, 0.66, 1.10, 0.97, 0.26), II 3.56 (1.20, 0.33,1.03, 0.84, 0.16), III 3.26 (1.19, 0.19, 1.11, 0.64, 0.13), IV 4.11 (1.23, 0.42, 1.22, 0.87, 0.37). Prosoma diamond-shaped, with gentle undulations at the outer edges and clearly extended posterior tip, coloured bright reddish orange with small puncture and covered with fine setae. Eyes arranged in two rows, anterior median eyes dark and rounded, anterior and posterior lateral eyes smallest, close to each other, posterior median eyes the largest, oval shaped, bright silver in colour.
Opisthosoma ovally elongated, dorsally and ventrally covered with fine setae, uniformly coloured, reddish-brown with small whitish spots and with two elongate orange spots in the dorsal mid part and one on each side of the dorsal side of the opisthosoma close to the prosoma. Sternum, chelicerae and labium uniformly reddish-brown. Pedipalps, legs and ventral scutum yellowish-orange. Pedipalp: as in Fig. 2a-e, for the re-description see Platnick & Shadab (1974).
Distribution. The species was previously known from the west and east coast of southern India: Bombay/Mumbai (locus typicus) (Pickard-Cambridge 1871), Puducherry (Simon 1884), Andrah Pradesh, Karnataka and Maharashtra (Platnick & Shadab 1974). It was already the most widespread species of the family. The new record from Iraq (the westernmost and northernmost distribution limit of the entire family) extends the range of the species 3000 km to the west (Fig. 3).
Comment. The specimens of the current study were found side by side with members of the genus Palpimanus, Palpimanidae (under the same dry mud mounds, Fig. 4).
Fig. 2.
Stenochilus hobsoni, male pedipalp. a. prolateral view; b, d. ventral view; c, e. retrolateral view (d, e after Platnick & Shadab 1974: figs 7-8)
Acknowledgements
I am grateful to Mr. Akram Jabbar for allowing me to enter his barley field and helping to collect specimens. I thank the late great Dr. Norman I. Platnick (USA) and Hisham K. El-Hennawy (Egypt) for providing scientific advice and confirming the identity of species. I express my gratitude to the anonymous reviewers for their valuable scientific and technical notes.
