A new distribution record of Eirenis walteri (Boettger, 1888) (Ophidia: Colubridae), In Yazd province, Central Iran

1. Introduction

The genus Eirenis, as defined by Jan (1863), encompasses 20 species of colubridae, colloquially referred to as "dwarf snakes" ( 3 ). These species are distributed across a range of countries, including southern Armenia, southern Turkmenistan, southern and southeastern Turkey, eastern Iraq, Iran, and potentially Pakistan, Afghanistan, and parts of India ( 1 , 20 , 13 , 19 ). Additionally, they are found in southeastern Europe ( 21 , 10 ). Dotsenko (1989) identified two subgenera based on the number of dorsum scales at Eirenis (Eirenis), which has 17, and Eirenis (Collaria), which has 15. Three distinct morphs have been documented for this species, which are designated as the persicus, walteri, and nigrofasciatus morphs. The Walteri morph exhibits pale dark blotches on the head similar to those observed in the Persicus morph, in addition to narrow dorsal crossbars on the anterior portion of the dorsum that gradually disappear towards the posterior portion of the body. All Eirenis persicus specimens exhibiting the persicus and walteri morphologies are designated as Eirenis persicus persicus (Anderson, 1872). This classification is based on the findings of Dotsenko (1989, 5, 20), who demonstrated that specimens exhibiting a walteri pattern are predominantly female, while those displaying a persicus pattern are primarily male ( 10 , 16 ). A review of the literature revealed that the genus Eirenis, comprising 13 species, exhibits the greatest diversity in Iran ( 17 , 7 , 13 ) (Figure 1). Conversely, other studies have indicated that the highest diversity, with 11 species, occurs in Turkey ( 3 , 21 ). A minimum of ten species within this genus are identical between Iran and Turkey ( 22 ). The genus has been divided into four subgenera based on mitochondrial Cytb and 16s genes, as follows: The new subgenus Eoseirenis (on decemlineatus), Pseudocyclophis Boettger, 1888 (on persicus) and Pediophis Fitzinger, 1843 (on all remaining taxa) ( 12 ) are also worthy of note. The identification of characters for the Eirenis species is as follows: small eyes, a circular pupil in the head, the presence of a loreal plate in most species, subcaudal scales that are divided, one preocular, a dorsum that is devoid of keeled scales, and an anal plate that is divided into seven, ten, and fourteen. A review of the literature reveals that 13 species of Eirenis have been documented in Iran. These include Eirenis coronella (Schlegel, 1837), Eirenis collaris (Ménetriés, 1832), Eirenis coronelloides (Jan, 1862), and E. The species include Eirenis decemlineatus (Duméril, Bibron & Duméril, 1854), E. kermanensis Rajabizadeh, Schmidtler, Orlov and Soleimani, 2012, E. medus Chernov, 1940, E. modestus (Martin, 1838) ( 9 ), E. nigrofasciatus (Nikolsky, 1907), E. occidentalis Rajabizadeh et al. In 2016, the following species were recorded: Eirenis persicus (J. Anderson, 1872), E. punctatolineatus (Boettger, 1892), Eirenis rechingeri Eiselt, 1971 and E. walteri (Boettger, 1888) ( 15 , 8 , 18 ). An investigation by Nilson and Rastegarpouyani ( 11 ) reported the presence of Eirenis coronelloides in the western region of Iran. They added it to the Iranian snakes checklist based on the incidence of two specimens of this snake in Kermanshah Province of Iran. The genus Eirenis is currently unrepresented in Iran, as new species and subspecies continue to be identified. For instance, Eirenis rafsanjanicus sp. is distinguished by genetic data (6% in Cytb) that is most similar to the recently described E. yassujicus, which is endemic to high-altitude regions in southern Iran ( 2 ). It is therefore imperative that all reports from all regions be taken into account. Eirenis walteri. In the course of this research, one of the cases that merits particular attention is the examination of the distribution of species within the genus Eirenis.

Figure 1. Current Range of Eirenis walteri distribution in Iran.

2. Materials and Methods

The specimen was procured from Ghotrom village (Kouh-e-Bafgh Protected Area), situated 46 km southeast of Bafgh County, Yazd Province, Iran (31°25' 18.60'' N and 55° 47' 51.58''E, elevation 1540 meters) during June 2019. Over 80% of the village is comprised of arid terrain. The village of Ghotrom is situated in a geographical area comprising two distinct regions: the Bajegan Mountains and the mountain valley. The village itself is concentrated in the valley, occupying a shape that reflects its topographical location. In general, the climate of the village is moderate and arid, semi-arid, or cold semi-humid (Figure 2).

Figure 2. Ghotrom village in Kouh-e-Bafgh Protected area. Photo by Hamid Morad Alizadeh.

3. Results

The specimen in this research was identified by examining the scales on all aspects of the body (Figure 3). Meristic characters and mensural characters were investigated (Table 1). pending present study, additional specimens of Walteris dwarf snake are reported in Ghotrom village (Kouh-e-Bafgh Protected area), in Yazd Province, central Iran (Figure 4). Records show that E. walteri is not invader species like the other morph of this species. Meanwhile rodents can be the main preys for the E. walteri in the Kouh-e-Bafgh Protected area. The Eirenis walteri is typically observed in habitats characterised by soft sand aunes in close proximity to vegetation, including bushes and other forms of ground cover. This is likely due to the species' utilisation of these areas as refuges. The Eirenis walteri is also found in semi-arid lowlands, rocky slopes in mountainous semi-desert regions, and limestone terrain with stony, sparse grassland. The only previously known precise locality for E. walteri in Iran was Dehbakri, situated in the Kerman province in the south-eastern region of the country ( 16 ). This record from Bafgh represents a southward extension of the species' range by approximately x km. The addition of these records from Iran enhances our understanding of the distribution and diversity of the herpetological fauna in the region. Nevertheless, further data are required in order to gain a fuller understanding of the distribution, taxonomy and historical biogeography of E. walteri.

Figure 3. Different aspects of the specimen found in Yazd, Dorsal head aspect (A), Lateral head aspect (B), Ventral head aspect (C), General aspect (D).

Figure 4. Location of Yazd province (blue) in central Iran (right), and accurate and approximate localities of the specimens of E. walteri from Ghotrom Village in Kouh-e-Bafgh Protected area (left).

4. Discussion

It is noteworthy that Zare Khormizi (2023) included the E. walteri among the snake fauna of Yazd province based on the specimen of this species in this research. The genus Eirenis of dwarf snakes represents a critical group within the Colubridae family of snakes. The presented paper introduces new distribution records for the Eirenis walteri species and provides an updated, annotated list of the Eirenis species currently known from Iran. As previously reported by Rajabzadeh ( 16 ), the distribution of E. walteri is believed to be extensive, encompassing central and eastern areas of Iran. This conclusion is supported by the current report from Yazd Province (Figure 5). In a previous study, Rajabzadeh ( 16 ) simulated the distribution of the dwarf snake Eirenis persicus (Anderson, 1872), which included the eastern region of Iraq, southern and southeastern Turkey, southern Armenia, southern Turkmenistan, Iran, southern Turkmenistan, and potentially parts of Afghanistan, Pakistan, and northwestern India. The presence of this snake in the centre of Iran may represent the final component of this extensive distribution, thus increasing the geographical range of the Walters dwarf snake from the east to the centre of Iran. Based on this research, Yazd province is included within the distribution range of the Eirenis walteri species.

Figure 5. Habitat of E. walteri at a locality, Ghotrom village that 46 km southeast of Bafgh County, Yazd Province, southeast Iran. Photo by Hamid Morad Alizadeh.

Acknowledgment

We are grateful to Dr Mehdi (Khosrow) Rajabizadeh of the Department of Biodiversity at the Institute of Science and High Technology and Environmental Sciences, Graduate University of Advanced Technology, Kerman, Iran, for confirming the species of snake in question.

Authors' Contribution

Study concept and design: A.S, M.Z

Acquisition of data: A.S, M.Z

Analysis and interpretation of data: A.S, A.T

Drafting of the manuscript: M.J, A.T

Critical revision of the manuscript for important intellectual content: A.S, M.Z

Statistical analysis:

Administrative, technical, and material support:

Study supervision: A.T

Ethics

Ethics committee of the Razi Vaccine and Serum Research Institute (No. RVSRI.REC.98.016).

Conflict of Interest

The authors declare that they have no conflict of interest.

Funding

This research did not receive any specific funding from public agencies, or commercial or not-for-profit organizations

Data Availability

The data that support the findings of this study are available on request from the corresponding author.

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