{"id":1250,"date":"2012-10-03T19:56:37","date_gmt":"2012-10-03T17:56:37","guid":{"rendered":"http:\/\/blog.moroccoherps.com\/?page_id=1250"},"modified":"2020-01-12T23:48:59","modified_gmt":"2020-01-12T23:48:59","slug":"taxonomic-troubles-in-the-hemorrhois-genus-in-morocco","status":"publish","type":"page","link":"https:\/\/www.moroccoherps.com\/en\/taxonomic-troubles-in-the-hemorrhois-genus-in-morocco\/","title":{"rendered":"Taxonomic troubles in the Hemorrhois genus in Morocco"},"content":{"rendered":"

by Gabriel Mart\u00ednez del M\u00e1rmol Mar\u00edn & David Donaire Barroso.<\/strong><\/p>\n

In 2001 were recognized the genera Hemorrhois<\/span>, Hierophis<\/span> and Platyceps<\/span> for some of the species previously assigned to Coluber<\/span> (Sch\u00e4tti & Utiger, 2001; Sch\u00e4tti et al.<\/em> 2001).<\/p>\n

Four species are nowadays recognized in the genus Hemorrhois<\/span> Boie, 1826: Hemorrhois hippocrepis<\/span> (Linneo, 1758), Hemorrhois algirus<\/span> (Jan, 1863), Hemorrhois nummifer<\/span> (Reuss, 1834) and Hemorrhois ravergieri<\/span> (M\u00e9n\u00e9tries, 1832). These snakes are known for their colour pattern variability. The eastern species (H.\u00a0nummifer<\/span> and H.\u00a0ravergieri<\/span>) can even have designs that mimics the designs of the vipers of their same habitat. In other species is possible the change of the coloration with the age (H.\u00a0algirus<\/span>; Arnold & Burton, 1997; Baha el Din, 2006).<\/p>\n

Only two species are known to occur in Morocco: H.\u00a0algirus<\/span> and H.\u00a0hippocrepis<\/span> (Bons & Geniez 1996) and the Maghreb.<\/p>\n

H. hippocrepis<\/span> is a large, thin and strong snake with big eyes, smooth scales and beautiful design based in rounded marks and a typical horseshoe mark in the head. It\u00b4s range covers the Iberian Peninsula, Morocco, Tunisia and some islands where it has been probably introduced recently (Sardinia, Balearic islands, etc\u2026). It is one of the most common snakes in Morocco and occurs in the areas with Mediterranean clima north of the high Atlas chain, the Souss Valley reaching the south Atlantic coast until 20 Km north of Tan-tan (Bons & Geniez, 1996; Leon Vigara, 2012) and it has been recently found in Tendrara (B. Rebollo Fernandez & G. Martinez del Marmol, unpublished).<\/p>\n

\n
\"Hemorrhois
Hemorrhois hippocrepis. Casablanca (Morocco). Photo: \u00a9 Gabri Mtnez.<\/figcaption><\/figure>\n<\/div>\n
\n
\"Habitat
Hemorrhois hippocrepis. Habitat in Casablanca (Morocco). Photo: \u00a9 Gabri Mtnez.<\/figcaption><\/figure>\n<\/div>\n

H. algirus<\/span> is smaller and thiner than H. hippocrepis<\/span>. It occurs in Morocco, Western Sahara, Mauritania, Algeria, Tunisia, Lybia, Egypt and Malta. In Morocco and Western Sahara is represented by the subspecies intermedius Werner, 1929 (Geniez et al.<\/em>, 2004), characterizated by a design of transversal bars along the body and horseshoe mark on the head following the original description of Werner (1929) but also by individuals with rounded blotches and horseshoe mark and grey-black headed individuals (Bons & Geniez, 1996). It occurs in a restricted distribution in Morocco limited to the Saharan zones (Bons & Geniez, 1996).<\/p>\n

\n
\"Hemorrhois
Hemorrhois algirus algirus, adult. Tunisia. Photo: \u00a9 Tomas Mazuch.<\/figcaption><\/figure>\n<\/div>\n
\n
\"Hemorrhois
Hemorrhois algirus algirus, subadult. Tunisia. Photo: \u00a9 Tomas Mazuch.<\/figcaption><\/figure>\n<\/div>\n
\n
\"Hemorrhois
Hemorrhois algirus intermedius. Guelmim (Morocco). Photo: \u00a9 Philippe Geniez.<\/figcaption><\/figure>\n<\/div>\n

Although the specific rank of Hemorrhois algirus<\/span> and Hemorrhois hippocrepis<\/span> has been ascertained (Schatti & Utiger, 2001; Nagy et al.<\/em>, 2004; Carranza et al.<\/em>, 2006; Wuster et al.<\/em>, 2007), the number of samples used is very low (Schatti & Utiger used samples from Rabat, Agadir and \u201cMorocco\u201d for hippocrepis<\/span> and a Tunisian sample for algirus<\/span>; Nagy et al.<\/em> used samples of Tantan plage for algirus<\/span> and a spanish sample for hippocrepis<\/span>; Carranza et al.<\/em> used just one algirus<\/span> sample from Tunisia and many hippocrepis<\/span> samples but all of them from north of the Atlas Chain so no \u201cintermediate\u201d individuals were compared to \u201cpure\u201d algirus<\/span> or hippocrepis<\/span> and Wuster et als samples has no origin known), the distribution of both species it is not totally clear in contact areas between both species. Bons & Geniez (1996) mentioned the difficulty to identify some individuals from the Anti Atlas chain in Morocco.<\/p>\n

\n

\"Hemorrhois<\/p>\n

\"Hemorrhois
Hemorrhois sp. with a grey coloration and with an absent horseshoe mark, pale dorsal circled marks, 25 rows of dorsal scales, in one side of the head the eye contact with a supralabial scale and in the other side there is a scale row between eye and supralabial scales (found by B. Rebollo Fernandez & G. Martinez del Marmol). Igherm (Morocco). Photos: \u00a9 Gabri Mtnez.<\/figcaption><\/figure>\n<\/div>\n

Along the Atlantic coast of south Morocco, from Tiznit to Tan-Tan some ecological particularities allow that snakes of different biogeographycal origins occur in sympatry: tropical-sahelian snakes (Boaedon fuliginosus<\/span>, Dasypeltis sahelensis<\/span>, Bitis arietans<\/span>, Naja haje<\/span>), Mediterranean snakes (Macroprotodon brevis<\/span>, Hemorrhois hippocrepis<\/span>, Malpolon monspessulanus<\/span>, Daboia mauritanica<\/span>, Natrix maura<\/span>) and Sindo-Saharan snakes (Cerastes cerastes<\/span>, Cerastes vipera<\/span>, Hemorrhois algirus<\/span>, Rhagerhis moilensis<\/span>, Spalerosophis dolichospilus<\/span>, Psammophis schokari<\/span>, Lytorhynchus diadema<\/span>).<\/p>\n

\n
\"\"
Contact area habitat. Between Guelmim and Tantan where H.\u00a0hippocrepis meets H.\u00a0algirus (Morocco). Photo:\u00a0\u00a9\u00a0Gabri\u00a0Mtnez.<\/figcaption><\/figure>\n<\/div>\n

Moreover the extreme variability of design in both species in Morocco snakes makes indentification impossible based on current published keys alone and thus the relations between both species continue unclear (Bons, 1962; Bons & Geniez, 1996). Following Schleich et al.<\/em> (1996) the main differences between both species are:<\/p>\n

\n

Table 1:<\/strong> Based in Schleich et al.<\/em>, 1996.<\/span><\/p>\n\n\n\n\n\n\n\n\n\n\n\n
<\/th>\nH. hippocrepis<\/span><\/th>\nH. algirus<\/span><\/th>\n<\/tr>\n<\/thead>\n
dorsal design<\/th>\nrounded marks<\/td>\ntrasversal bars<\/td>\n<\/tr>\n
horseshoe mark<\/th>\nyes<\/td>\nno<\/td>\n<\/tr>\n
supralabial scales in contact with the eye<\/th>\nRarely<\/td>\nAlways 1 or 2<\/td>\n<\/tr>\n
scales at midbody<\/th>\n25-29<\/td>\n23-25<\/td>\n<\/tr>\n
ventral scales<\/th>\n214-258<\/td>\n209-237<\/td>\n<\/tr>\n
subcaudal scales<\/th>\n72-109<\/td>\n83-110<\/td>\n<\/tr>\n
anal scale<\/th>\nusually is divided<\/td>\nsometimes divided<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

However this information contrast with Werner (1929), Bons & Geniez (1996) and Geniez (2004) who include some Hemorrhois<\/span> individuals with horseshoe mark in H.\u00a0algirus<\/span>. In contrast, Sochurek (1979) described these specimens as a subspecies of H.\u00a0hippocrepis<\/span> and suggested the possibility of being a full species or a hybrid between H.\u00a0algirus<\/span> and H.\u00a0hippocrepis<\/span>. In fact, the Schleich et al.<\/em>\u2019s description agrees with the eastern form, H.\u00a0a.\u00a0algirus<\/span>, but not with the western form, H.\u00a0a.\u00a0intermedius<\/span> (including \u201cColuber algirus villiersi<\/span>\u201d Bons, 1962; Geniez et al.<\/em>, 2004) which can exhibit a horshoe mark and rounded blotches on the dorsum, and has rarely a dark headed colouration. Even in the eastern form, has been published the possibility of 27 rows of dorsal scales at midbody (in most Malta specimens; Bons in Joger, 1997). Le Berre (1989) published that Coluber florulentus<\/span> (includying H.\u00a0algirus<\/span>) has between 21-25 rows of dorsal scales at midbody, whereas to Gruber (1993) and Baha el Din (2006) all specimens of Hemorrhois algirus<\/span> have 25 rows.<\/p>\n

\n

\"Hemorrhois<\/p>\n

\"Hemorrhois
Hemorrhois algirus intermedius (found by Raul Leon Vigara & Gabri Mtnez). Erfoud (Morocco). Photos: \u00a9 Gabri Mtnez.<\/figcaption><\/figure>\n<\/div>\n

In Morocco (including Atlantic Sahara), western Algeria and Mauritania, some specimens can have a horseshoe-mark and can have a design of transverse bars (fitting with the Werner\u00b4s description of Coluber algirus intermedius<\/span>). But it is also possible to find Hemorrhois sp.<\/span> with unicolour head and unbranded horseshoe mark but with circular markings similar to H.\u00a0hippocrepis<\/span>. Schatti (1986) argued that the distinction of two subspecies of the Algerian whip snake (algirus<\/span> and intermedius<\/span>) is not conclusive because reliable characters are lacking.<\/p>\n

About head pholidosis, it is common to find specimens with one side of the head with a supralabial scale in contact with the eye, but on the other side there is a row of scales between the eye and supralabials, in other cases on both head sides one or two supralabials scales are in contact with the eye, and sometimes on both sides of the head there is a row of scales between the eye and supralabials so the supralabial scales and their contact with the eyes is not a reliable characteristic to distinguish both species. Such individuals sometimes have a typical H.\u00a0hippocrepis<\/span> design but too pale and in the H.\u00a0algirus<\/span> typical habitat (pers. obs. in Tata, Igherm, Aouinet Lahna, Plage Blanche, Ouarzazate surroundings). Even in Tata we have seen individuals with 23 and 25 rows of mid-dorsal scales very close.<\/p>\n

\n

\"Hemorrhois<\/p>\n

\"Hemorrhois
Hemorrhois sp. with design H. hippocrepis but pallid coloration. Aouinet Lahna (Morocco). Photos: \u00a9 Michel Aymerich.<\/figcaption><\/figure>\n<\/div>\n
\n

\"Hemorrhois<\/p>\n

\"Hemorrhois
Hemorrhois sp. (found by J.P. Gonzalez de la Vega; L. Garcia-Cardenete; J.R. Fernandez Cardenete; V. Gabari Boa; F. Jimenez-Cazalla; J.A.M. Barnestein; J.A. Fernandez Carrasco & G. Martinez del Marmol). Tata (Morocco). Photos: \u00a9 Gabri Mtnez.<\/figcaption><\/figure>\n<\/div>\n
\n
\"Hemorrhois
Hemorrhois algirus. Tata (Morocco). Photos: \u00a9 Gabri Mtnez.<\/figcaption><\/figure>\n<\/div>\n
\n
\"\"
Hemorrhois sp. and H. algirus habitat. Tata (Morocco). Photo: \u00a9 Gabri Mtnez.<\/figcaption><\/figure>\n<\/div>\n
\n
\"Hemorrhois
Hemorrhois hippocrepis. Tendrara (Morocco). Photo: \u00a9 Gabri Mtnez.<\/figcaption><\/figure>\n<\/div>\n

The extreme variability of individuals suggests some questions:<\/p>\n

– Is it possible to group all these odd individuals in a subspecies of H.\u00a0hippocrepis<\/span> or H.\u00a0algirus<\/span> as it has been done historically with the subspecies “intermedius<\/span>“?<\/p>\n

– Would it be possible that in large areas of contact between both species hybridization has occurred and the so called subspecies “intermedius<\/span>” is simply the product of a continuum hybridization zone of both Hemorrhois<\/span>?<\/p>\n

Against this latter hypothesis points out that following the distribution maps of Bons & Geniez (1996) most specimens of H.\u00a0algirus<\/span> with circular markings have been found outside the contact area with H.\u00a0hippocrepis<\/span>. It is precisely in the contact area with H.\u00a0hippocrepis<\/span> where more specimens were found with transversal bars design.<\/p>\n

Although this could also be because most specimens with rounded blothches of the contact area could be automatically assigned to H.\u00a0hippocrepis<\/span>. But it seems very rare that Hemorrhois algirus<\/span> has evolved with the horseshoe mark without any gene flow of H.\u00a0hippocrepis<\/span> although the presence of sympatric areas and \u201cintermediate\u201d individuals.<\/p>\n

\n
\"Mapa\"
Map. Red colour to Hemorrhois\u00a0hippocrepis distribution area; Yellow spots to H.\u00a0algirus with trasversal bars; green spots to H.\u00a0algirus with round marks & blue spots to black headed H.\u00a0algirus (based in Bons & Geniez, 1996).<\/figcaption><\/figure>\n<\/div>\n
\n

\"Hemorrhois<\/p>\n

\"Hemorrhois
Hemorrhois algirus intermedius. Tantan (Morocco). Photos: \u00a9 Michel Aymerich.<\/figcaption><\/figure>\n<\/div>\n
\n

\"Hemorrhois<\/p>\n

\"Hemorrhois
Hemorrhois algirus intermedius. Dakhla (WS). Photos: \u00a9 Michel Geniez.<\/figcaption><\/figure>\n<\/div>\n
\n
\"Hemorrhois
Hemorrhois algirus intermedius. Habitat in Tantan (Morocco). Photos: \u00a9 Gabri Mtnez.<\/figcaption><\/figure>\n<\/div>\n
\n
\"Hemorrhois
Hemorrhois hippocrepis with strange design. Lakhsas (Morocco). Photos: \u00a9 Gabri Mtnez.<\/figcaption><\/figure>\n<\/div>\n
\n
\"Hemorrhois
Hemorrhois \u201chippocrepis\u201d. Jebel Sirwa (Morocco). Photos: \u00a9 Fernando Martinez-Freiria.<\/figcaption><\/figure>\n<\/div>\n

A genetic analysis with wide sampling (mostly \u201cintermediate\u201d and \u201cstrange\u201d individuals) is madatory to clarify the taxonomical situation of this genus in Morocco.<\/p>\n

Acknowledgements<\/strong><\/p>\n

Thanks to Philippe Geniez for his information and photos. To Mario Schweiger for his information and helping in the german translations. To Michel Aymerich, Tomas Mazuch and Fernando Martinez-Freiria, for their photos.<\/p>\n

\n

To cite this page:<\/strong>
\nGabriel Mart\u00ednez del M\u00e1rmol Mar\u00edn & David Donaire Barroso: Taxonomic troubles in the Hemorrhois<\/span> genus in Morocco.
\nPublished on October 03, 2012. Updated on October 18, 2012. Available from http:\/\/blog.moroccoherps.com\/taxonomic-troubles-in-the-hemorrhois-genus-in-morocco\/<\/a>. Accessed [php snippet=1].<\/p>\n

To cite www.moroccoherps.com<\/a> as a whole:<\/strong>
\nAmphibians & Reptiles of Morocco and Western Sahara.
\nAvailable from www.moroccoherps.com<\/a>. Accessed [php snippet=1].<\/p>\n<\/div>\n

Bibliography:<\/h3>\n