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Issue: Vol. 5693 No. 1: 16 Sept. 2025
Type: Article
Published: 2025-09-16
DOI: 10.11646/zootaxa.5693.1.3
Page range: 41-65
Abstract views: 129
PDF downloaded: 0

Phenotypic variability in the western grass snake Natrix astreptophora, with description of a new subspecies from Morocco

Calle Pedro Antonio de Alarcón 34; 5º A; 18002; Granada; Spain.
CEFE; Univ Montpellier; CNRS; EPHE-PSL University; IRD; Biogéographie et Écologie des Vertébrés; 1919 route de Mende; 34293 Montpellier Cedex 5; France.
Zoologische Staatssammlung München (ZSM-SNSB); Münchhausenstraße 21; 81247 München; Germany.
Zoologische Staatssammlung München (ZSM-SNSB); Münchhausenstraße 21; 81247 München; Germany.
Museum of Zoology; Senckenberg Dresden; A.B. Meyer Building; 01109 Dresden; Germany.; Institute of Biology; University of Leipzig; Talstraße 33; 04103 Leipzig; Germany.
Reptilia Algeria France melanism Morocco Natricidae Natrix astreptophora soumiafahdae subsp. nov. Portugal Serpentes Spain Squamata taxonomy Tunisia

Abstract

Based on a large sample of 920 Natrix astreptophora (López Seoane, 1884) from Western Europe and 32 specimens from North Africa, we examine phenotypic variation in this species. In agreement with genetic findings of previous phylogeographic studies, we distinguish three subspecies. The nominotypical subspecies is distributed in the European part of the distribution range. Natrix astreptophora algerica (Hecht, 1930) lives in northeastern Algeria and northern Tunisia. Moroccan grass snakes represent Natrix astreptophora soumiafahdae subsp. nov., which is described here as new to science. All three subspecies differ in coloration and pattern and represent three deeply divergent genetic lineages as reflected by mitochondrial and nuclear DNA. Natrix astreptophora soumiafahdae subsp. nov. is very rare and has a fragmented distribution range. It represents an evolutionarily significant conservation unit for which conservation measures are needed. In addition, across the distribution range of the nominotypical subspecies, three non-melanistic phenotypes can be distinguished that also differ in coloration and pattern. One of these phenotypes is widespread across the whole European range, while two are geographically restricted to the north and west of the Iberian Peninsula, respectively, where they may co-occur with the other phenotypes. In addition, there is a clear correlation between the distribution of melanistic grass snakes and latitude; 45 of the 46 melanistic N. a. astreptophora were recorded from the northern and northwestern Iberian Peninsula. There are no records for melanistic grass snakes in North Africa.

 

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How to Cite

Mármol, G.M.D., Geniez, P., Neumann, A., Glaw, F. & Fritz, U. (2025) Phenotypic variability in the western grass snake Natrix astreptophora, with description of a new subspecies from Morocco. Zootaxa, 5693 (1), 41–65. https://doi.org/10.11646/zootaxa.5693.1.3