Swimming in the Sahara: A new locality record and range extension of Natrix maura (Linnaeus, 1758) (Squamata, Colubridae), from central Algeria

Study Extent

Field observations were conducted at Sebkhet El Melah wetland (30° 28' 06" N, 2° 55' 35" E; 370 m a.s.l.; fig. 1A), El Menia Province (formerly El Goléa), central Algeria. This shallow, saline lake covers about 8 km² and is bordered by sand dunes and rocky hills. It receives water from surrounding palm grove drainage, El Menia city domestic wastewater, and rainfall (Hacěne et al., 2004; Alioua et al., 2016). Designated as a Ramsar Site (https://rsis.ramsar.org/ris/1429), Sebkhet El Melah is a critical habitat for Saharan biodiversity, particularly waterbirds (Bouzid et al., 2009, 2019, 2023; Chedad et al., 2021). Based on data from the WorldClim database with a resolution of ~1 km² (Fick and Hijmans, 2017), the site falls within the inferior Saharan bioclimatic zone, characterized by temperate winters and a mean annual precipitation of 30 mm.

Sampling

To comprehensively update N. maura distribution in Algeria, we conducted a thorough literature review and searched online museum and institutional collections for occurrence records.

Quality Control

Additionally, occurrence data were obtained from the Global Biodiversity Information Facility (GBIF, 2024) and iNaturalist (https://inaturalist.org). Following Chowdhury et al. (2024), data were also sourced from Facebook (https://facebook.com), specifically from the group named “world of wildlife in Algeria (https://www.facebook.com/groups/1641684429224291/).

Method steps

1. The species identification of data obtained from both iNaturalist and Facebook was double-checked and confirmed by the authors. To ensure data accuracy, all records included precise locality description and/or GPS coordinates with a minimum precision of two decimal degrees, while excluding records with coordinates referring to the centroids of large geographic areas. Duplicate records from the same locality were merged into single entries. The final dataset comprised 139 unique presence locations (annex 1) visualized using ArcGIS v. 10.8.

1. Chordata
   rank: phylum
2. Reptilia
   rank: class
3. Squamata
   rank: order
4. Colubridae
   rank: family
5. Natrix
   rank: genus
6. Natrix maura
   rank: species

Field observations were conducted at Sebkhet El Melah wetland (30° 28' 06" N, 2° 55' 35" E; 370 m a.s.l.; fig. 1A), El Menia Province (formerly El Goléa), central Algeria. This shallow, saline lake covers about 8 km² and is bordered by sand dunes and rocky hills. It receives water from surrounding palm grove drainage, El Menia city domestic wastewater, and rainfall (Hacěne et al., 2004; Alioua et al., 2016). Designated as a Ramsar Site (https://rsis.ramsar.org/ris/1429), Sebkhet El Melah is a critical habitat for Saharan biodiversity, particularly waterbirds (Bouzid et al., 2009, 2019, 2023; Chedad et al., 2021). Based on data from the WorldClim database with a resolution of ~1 km² (Fick and Hijmans, 2017), the site falls within the inferior Saharan bioclimatic zone, characterized by temperate winters and a mean annual precipitation of 30 mm.