Slow worm (Anguis colchica)

27 November 2016

The slow worm is a limbless elongated lizard. It is the only limbless lizard species in Romania and it can be easily mistaken for a snake. In vernacular language, this species is also named Glass snake, due to the fact that it „breakes” (the lizard can separate its tail rom the body), a phenomena called autotomy.

Until recently the species, scientific name was Anguis fragilis colchica, subsequently the subspecies being raised to species rank.

The species is present in all European countries, except the cold Northern regions. [6]

The Geographic Range of Anguis colchica in Europe [6]

The Geographic Range of Anguis colchica in Europe [6]

In Romania the species is encountered more often in the central regions but it is encountered in other regions of the country as well. [3, 4, 5]

The Geographic Range of Anguis colchica in Romania [3]

The Geographic Range of Anguis colchica in Romania [3]

Morphology. It can reach 50 cm in length. The lack of limbs contributes to its serpent-like look. The eyes of this lizzard are small, with round pupil and mobile eyelids. The nozzle is cone-shaped and the external opening of the ear duct is visible. The tail has a round section, it is thick and twice as long as the rest of the body the transition from the body to the tail being undetectable. The body is covered in small, smooth and round scales. They have a vitreous luster, being equal in size, shape and position both on the dorsal and on the ventral side. It has a single internazal shield, separated from the nasals by two plaques. The frontal is singular, neighbouring two prefrontals, two long and narrow parietals; the nazals are small and are separated from the rostral by a plaque, and the supraoculars vary from 5 to 6. It has from 26-29 rows of scales, as counted in transversal ring-like succesions. Males are differentiated from the females by their large heads and the occurence of blue dorsal spots. Females are larger than same age males and have a darker dorsal stripe and flanks. [4, 5, 11]

Ecology. The species is active mainly during twilight, being encountered in plain, hilly and montanous areas. It can be found in sunny spots in damp habitats, forests, on the edge of the forests, in pastures and orchards, living in underground borrows dug by various small mammals, in the cracks at the base of the trees, under the rocks, fallen trees, hay stacks or even in ant hills. It can be easily captured since it is slow moving and never bites. It feeds on snails, earth worms and various arthropods, and this type of food is closely related to lizzard’s activity, which is active immediately after a rainfall, during the first hours of the day and at sunset. Case of cannibalism were recorded for this species, a relatively common behavirous in amphibians and reptiles. Hibernation starts in October and they can sometimes hibernate in groups of several specimens. They are turning active in March, as soon as the temperatures warm up the ground. The species sheds several times a year, in patches, and it can live up to 46 years old. [1, 4, 5, 8, 9, 10]

Reproduction takes place in May, the male immobilising the female during coupling by biting the back of her neck. The species is ovoviviparous, in August the femail giving birth to 5-26 youngs, approximately 8.5 cm in length at birth. [4, 5]

Legislation. In Romania, the species is protected by Law no. 13 of 1993, by which Romania ratifies the Bern Convention (Annex III) and by Emergency Government Order no. 57/2007 regarding the protected areas regime, the conservation of natural habitats, wild flora and fauna, approved with further modifications and completions (Annex IV B), being considered a s national interest species requiring strict protection. [12, 13]

According to the IUCN classification, worldwide the species is considered non evaluated (NE), and in the Romania’s Vertebrates Red Book the species is noted as vulnerable (Vu). [7, 14]


1. Ceirans A., (2004): Reptiles in sub-boreal forests of Eastern Europe: patterns of forest type preferences and habitat use in Anguis fragilis, Zootoca vivipara and Natrix natrix. Herpetozoa 17: (1/2): 65-74.

2. Cicek K., Tayhan Y., Hayretdag S., Ayaz D., Tok V C., (2011): A case of cannibalism behavior of the Slow worm, Anguis fragilis (Reptilia: Anguidae) in Turkey, Biharean Biologist 5 (1): 76-77.

3. Cogălniceanu D., Rozylowicz L., Székely P., Samoilă C., Stănescu F., Tudor M., Székely D., Iosif R., (2013): Diversity and distribution of reptiles in Romania, ZooKeys 341: 49-76.

4. Fuhn I.E., Vancea Ș., (1961): Fauna R.P.R. Reptilia (Țestoase, Șopârle, Șerpi). Vol XIV, fasc. 2, Editura Academiei R.P.R., București.

5. Fuhn I.E., (1969): Broaște, șerpi, șopârle. Ed. Științifică, București.

6. Gasc J.P., Cabela A., Crnobrnja-Isailovic, Domen D., Groessenbacher K., Haffner P., Lescure J., Martens H., Marinez Rica J.P., Maurin H., Oliveira M.E., Sofianidou T.S., Veith M., Zuiderwijk A., (1997): Atlas of Amphibians and Reptiles in Europe. Societas Europaea Herpetologica & Museum National d’Histoire Naturelle Paris.

7. Iftimie A., (2005): Reptilia. In: Botnariuc & Tatole (eds): Cartea Roșie a Vertebratelor din România. Ed. Academiei Române, București.

8. Luiselli L., (1992): The diet of the Slow Worm, Anguis f. fragilis LINNAEUS, 1758, in the Tarvisio Forest (Carnic Alps, NE Italy). Herpetozoa 5 (3/4):91-94.

9. Polis, G.A. (1981): The evolution and dynamics of intraspecific predation. Annual Review of Ecology and Systematics 12: 225-251.

10. Polis, G.A., Myers, C.A. (1985): A survey of intraspecific predation among reptiles and amphibians. Journal of Herpetology 19: 99-107.

11. Sos T., Gábor H., (2010): Sexual Size Dimorphism in Eastern Slow-Worm (Anguis fragilis colchica, Reptilia: Anguidae). Russian Journal of Herpetology 16 (4): 304-310.

12. ***Legea 13 din 1993 prin care România ratifică Convenția de la Berna.

13. ***Ordonanţa de Urgenţă a Guvernului nr. 57/2007 privind regimul ariilor naturale protejate, conservarea habitatelor naturale, a florei şi faunei sălbatice, aprobată cu modificări și completări ulterioare.

14. ***


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