Aesculapian snake

The Aesculapian snake /ˌɛskjəˈleɪpiən/ (now Zamenis longissimus, previously Elaphe longissima), is a species of nonvenomous snake native to Europe, a member of the Colubrinae subfamily of the family Colubridae. Growing up to 2 metres (6.6 ft) in length, it is among the largest European snakes, similar in size to the four-lined snake (Elaphe quatuorlineata) and the Montpellier snake (Malpolon monspessulanus). The Aesculapian snake has been of cultural and historical significance for its role in ancient Greek, Roman and Illyrian mythology and derived symbolism. Z. longissimus hatches at around 30 cm (11.8 in). Adults are usually from 110 cm (43.3 in) to 160 cm (63 in) in total length (including tail), but can grow to 200 cm (79 in), with the record size being 225 cm (7.38 ft). It is dark, long, slender, and typically bronzy in color, with smooth scales that give it a metallic sheen. Juveniles can easily be confused with juvenile grass snakes (Natrix natrix), because juvenile Aesculapian snakes also have a yellow collar on the neck that may persist for some time in younger adults. Juvenile Z. longissimus are light green or brownish-green with various darker patterns along the flanks and on the back. Two darker patches appear in the form of lines running on the top of the flanks. The head in juveniles also features several distinctive dark spots, one hoof-like on the back of the head in-between the yellow neck stripes, and two paired ones, with one horizontal stripe running from the eye and connecting to the neck marks, and one short vertical stripe connecting the eye with the 4th to 5th upper labial scales. Adults are much more uniform, sometimes being olive-yellow, brownish-green, sometimes almost black. Often in adults, there may be a more or less regular pattern of white-edged dorsal scales appearing as white freckles all over the body up to moiré-like structures in places, enhancing the shiny metallic appearance. Sometimes, especially when pale in color, two darker longitudinal lines along the flanks can be visible. The belly is plain yellow to off-white, while the round iris has amber to ochre coloration. Melanistic, erythristic, and albinotic natural forms are known, as is a dark grey form. Although there is no noticeable sexual dimorphism in coloration, males grow significantly longer than females, presumably because of the more significant energy input of the latter into the reproductive cycle. Maximum weight for German populations has been 890 grams (1.96 lb) for males and 550 grams (1.21 lb) for females (Böhme 1993; Gomille 2002). Other distinctions, as in many snakes, include in males a relatively longer tail to total body length and a wider tail base. Scale arrangement includes 23 dorsal scale rows at midbody (rarely 19 or 21), 211-250 ventral scales, a divided anal scale, and 60-91 paired subcaudal scales (Schultz 1996; Arnold 2002). Ventral scales are sharply angled where the underside meets the side of the body, which enhances the species' climbing ability. Lifespan is estimated at about 25 to 30 years. The contiguous area of the previous nominotypical subspecies, Zamenis longissimus longissimus, which is now the only recognized monotypic form, covers most of France except in the north (up to about the latitude of Paris), the Spanish Pyrenees and the eastern side of the Spanish northern coast, Italy (except the south and Sicily), all of the Balkan peninsula down to Greece and Asia Minor and parts of Central and Eastern Europe up until about the 49th parallel in the eastern part of the range (Switzerland, Austria, South Moravia (Podyjí/Thayatal in Austria) in the Czech Republic, Hungary, Slovakia, south Poland (mainly Bieszczady/Bukovec Mountains in Slovakia), Romania, south-west Ukraine).