Reflexions about potential distribution of Echis leucogaster in North Africa
by Gabriel Martínez del Mármol Marin (firstname.lastname@example.org), Baudilio Rebollo Fernández (email@example.com) & Tomas Mazuch (firstname.lastname@example.org)
Genus Echis Merrem, 1820, is one of the most complex genera of snakes in Africa. Recent genetic analysis has shown that the genetic variability among Echis leucogaster and Echis pyramidum group is very low and some authors suggest the existence of a single species with several subspecies (Arnold et al., 2009).
Echis leucogaster or Echis pyramidum leucogaster is probably the rarest snake in Morocco (Aymerich et al., 2004). In 1996 in Morocco the only known populations were Aouinet Torkoz (now called Aouinet Lahna) and Ait-Semgane-n-el-Grara (originally attributed to Echis carinatus by Sochurek but later classified as Dasypeltis scabra by Stemmler, 1971)(Bons & Geniez, 1996).
Over the years both populations have been confirmed: in Aouinet Lahna the population is relatively abundant (Aymerich et al., 2004; K. Lazghem, pers. comm.; G. Martinez del Marmol Marín, pers. obs.) and it has also been found in nearby regions such as Tiglit (F. Cuzin in Herrmann et al., 2000). South of Ouarzazate the number of citations has also increased with up to 6 specimens found in 2009 in the area between Ait Semgane-n- el-Grara and Tasla (Escoriza et al., 2009; Aymerich, 2010) and other nearby points such as Amazer (J. Maran & Maran in Geniez, 1999) and Allougoum (Pook et al., 2009).
As the populations are more than 300 Km apart there was a question that there could be intermediate populations between both nucleuses, especially as there are many sites potentially favourable for the species (Brito et al., 2011).
During a herpetological trip to Morocco on April 30, 2012, some of the authors found a juvenile of this species (Martinez del Marmol & Rebollo Fernandez, 2012) on the outskirts of the town of Tata.
Figure 1: Photograph of the Echis leucogaster specimen found in Tata. Photo: © Baudilio Rebollo Fernández.
Figure 2: Photograph of the exactly habitat where it was found. Photo: © Baudilio Rebollo Fernández.
The importance of this record is that it shows that the distribution of Echis leucogaster in Morocco is not limited to two isolated nuclei. This report shows that Echis leucogaster has a much wider distribution than that previously thought and confirms the possibility of a continuous population.
Figure 3: Map showing the known distribution of Echis leucogaster in Morocco. Indicated as dark red dots known locations (according to Aymerich et al., 2004; Escoriza et al., 2009; Pook et al., 2009; Aymerich, 2010). The last record as yellow dot (Martinez del Marmol Marin & Rebollo Fernandez, 2012). The potential distribution for authors is drawn with a soft red coloration.
Prior to this sighting, some of the authors had prospected around Assa, Foum el Hisn and Akka but without success. These and other places as Tisgui-El-Haratine, Icht, Tissint or Foum Zguid are locations where this species could possibly occur as they contain similar characteristics.
Figure 4: Foum Zguid landscape. Photo: © Gabri Mtnez.
In the last genetic analysis the E. pyramidum haplotypes are in turn subdivided into western (Mauritania, Senegal, Morocco, western Mali) and eastern (Tunisia, Niger, eastern Mali) clades (Pook et al., 2009). Those two groups are in the beginning of the diversification and at this moment and knowledge they don’t deserve any taxonomic unit (e.g. subspecies). The Echis vipers found in Biskra, Algeria (Jiri Hales-Tomas Mazuch, pers. comm.), should belong to Echis leucogaster species, as the specimens from both sides (Morocco, Tunisia) of this locality according to DNA (Pook et al., 2009), coloration (dorsal patterns, white venters) and morphology analysis (D 29, V165, Scd 36, thus certainly not from the complex ocellatus).
Figure 5: Echis leucogaster. Aouinet Lahna (Morocco). Photo: © Gabri Mtnez.
Figure 6: Echis pyramidum?. Biskra (Algeria). Photo: © Jiří Haleš.
Figure 7: Echis pyramidum. Bou Hedma (Tunisia). Photo: © F. Kovařík.
If we would speculate to which populations belong (eastern vs. western) Biskra specimens may belong to the eastern clade, because this population is closer and without any geographical barrier. Whereas the E. pyramidum and “E. leucogaster” meeting area is in somewhere in Libya (and probably further south in the Chad and western Sudan; T. Mazuch, unpublished), the possibility of a contact area between both E. pyramidum clades is uncertain due to the scarcity of Algerian and Moroccan records. Maybe there are some populations between Ait Semgane and Biskra (Tazzarine, Figuig, Beni Ounif, Brezina or Laghouat are good examples where “Echis leucogaster” could occur). Although a morphology analysis shows that an animal from Biskra (Natural History Museum, London: BMNH 1907.4.6.55) has a distinctive hemipenis and may represent yet another taxon (Arnold et al., 2009), there are no other reasons (geographically or phylogenetically) to recognize this population as another taxon.
Figure 8: Map showing the potential distribution of Echis pyramidum in North Africa following Pook et al., 2009.
Eastern clade in yellow colour:
- Sidi Toui (Karen, 2003, in Kaupia Journal)
- Matmata (Pook et al., 2009)
- Bou Hedma (Joger, 2003, in Kaupia Journal)
- Near (Djebel Attig) Gafsa (Olivier, 1896)
- Tadjera, near Mettamer (Boulenger, 1890, also as reference for (6) Biskra population)
- NE and SE of Biskra (Chirio L. & Blanc C . P ., 1997 – Statut et distribution des Reptiles dans le massif de l’Aurès (Algérie) – Rev. Zool. afr., Tervuren, 111: 205-233.) Here is what wrotte Laurent Chirio to Tomas Mazuch: “I worked during 2 years in Khenchela (1984-86), north-east of Biskra, and made a thesis about reptiles of Aures montane. I found only one dead (and dry) specimen of Echis leucogaster in Hammam-Salahine, just near Biskra, and a piece of another dead one south-east of Biskra. This entire specimen is now in Paris Museum (MNHN).”
Western clade in red colour:
- Ait Semgane (Bons & Geniez, 1996 ; Escoriza et al., 2009 ; M. Aymerich, pers. comm.)
- Amazer (Aymerich et al., 2004)
- Allougoum (Pook et al., 2009)
- Tata (Martinez del Marmol & Rebollo Fernandez, 2012)
- Aouinet Lahna (Bons & Geniez, 1996; Aymerich et al., 2004 ; G. Martinez del Marmol, pers. obs.)
- Tiglit (Herrmann, Herrmann and Geniez, 2000)
Figure 9: Errachidia landscape, E. leucogaster habitat?. Photo: © Gabri Mtnez.
Figure 10: Habitat of E. pyramidum in Bou Hedma (Tunisia). Photo: © Tomas Mazuch.
- Arnold, N.; Robinson, M. & Carranza, S. 2009. A preliminary analysis of phylogenetic relationships and biogeography of the dangerously venomous Carpet Vipers, Echis (Squamata, Serpentes, Viperidae) based on mitochondrial DNA sequences. Amphibia-Reptilia, 30: 273-282.
- Aymerich, M., Borof-Aymerich, E. & Geniez, P., 2004. Neufunde der seltenen Weißbäuchigen Sandrasselotter Echis leucogaster Roman, 1972 in Marokko (Serpentes: Viperidae). Herpetozoa, 16 (3/4): 157-162.
- Aymerich, M. 2010. Vipere des pyramides ou Echide à ventre blanc (Echis leucogaster). Dans Groupe d´Etude et de Recherches des Ecologistes Sahariens. Mahraoui, L., Aymerich, M., Borof-Aymerich, E., Tarrier, M., Delacre, J. & Marseault, L. (Fondateurs). www.geres-asso.org. Visited in 15 january 2011
- Bons, J., & Geniez, P. 1996. Amphibiens et reptiles du Maroc (Sahara Occidental compris). Atlas biogéographique. Asociación Herpetológica Española, Barcelona, 319 pp.
- Boulenger, G.A. 1890. Catalogue of the Reptiles and Batrachians of Barbary (Morocco, Algeria, Tunisia), based chiefly upon the Notes and Collections made in 1880-1884 by M. Fernand Lataste. Tr. Zool. Soc. 13: 93-164.
- Brito, J.C.; Fahd, S.; Geniez, P.; Martínez-Freiría, F.; Pleguezuelos, J.M. & Trape, J-F. 2011. Biogeography and conservation of viperids from North-West Africa: An application of ecological niche-based models and GIS. Journal of Arid Environments (November 2011), 75 (11), pg. 1029-1037
- Chirio L. & Blanc C . P . 1997. Statut et distribution des Reptiles dans le massif de l’Aurès (Algérie) – Rev. Zool. afr., Tervuren, 111: 205-233
- Escoriza, D.; M. Metallinou, Donaire-Barroso, D., Amat, F., and Carranza, S. 2009. Biogeography of the White-Bellied Carpet Viper Echis leucogaster Roman, 1972 in Morocco, a study combining mitochondrial DNA data and ecological niche modeling. Butll. Soc. Cat. Herp., 18: 55-68.
- Herrmann, H.-W.; Herrmann, P. A. & Geniez, PH. 2000. Zur Verbreitung von Echis leucogaster ROMAN, 1972 in Marokko.– Salamandra, Rheinbach; 36 (3): 203-207.
- Joger U. 2003. Reptiles and Amphibians of southern Tunisia. Kaupia (Darmstadt), 12: 71-88 pp.
- Karen A. 2003. Les Parcs Nationaux de Tunisie. Kaupia (Darmstadt), 12: 3-17 pp.
- Maran, J. & Geniez, Ph. 1999. Nouvelles observations sur l´herpétofaune du Maroc, 7. Redécouverte de l´Echide à ventre blanc, Echis leucogaster Roman, 1972 (Reptilia, Serpentes, Viperidae) au Maroc.- Bull. Soc. Herp. France, Paris; 90: 63-64
- Martinez del Marmol Marin, G. & Rebollo Fernandez, B. 2012. An important new record of Echis leucogaster Roman, 1972 from Morocco. Herpetology Notes, volume 5: 229-231 (published online on 21 June 2012)
- Olivier M. E. 1896. Les Serpents de la Tunisie. Bull. Ass. franc, pour l’av. des se. Tunis, 25: 471-476 pp.
- Pook, C.E.;Joger, U.; Stumpel, N. & Wuster, W. 2009. When continents collide: phylogeny, historical biogeography and systematics of the medically important viper genus Echis (Squamata: Serpentes: Viperidae). Molecular Phylogenetics and Evolution 53: 792-807
- Stemmler, O. 1971. Die Eirschlange, Dasypeltis scabra (Linnaeus, 1758), eine weitere Aethiopische form in der Marokkanischen Herpetofauna. Zool. Abhl., Staat. Mus. Tierk., Berlin, 32: 69-73.