Rat Snake ( Ptyas mucosa Linnaeus, 1758 )

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Scientific Name: 
Ptyas mucosa (Linnaeus, 1758)
Regional Names: 
ಕೇರೆ ಹಾವು
Dhaman, Ghoda-Pachad, Ashadhia
Oriental Rat snake,
Yellowish-brown adult. Madhya Pradesh
Venom Type: 
Characteristics for identification: 
Very long body with dark color patterns on the whole dorsal surface. Posterior body reticulated with black colour net like markings which continues to end of tail. Traditionally people differentiate between Cobra and Rat Snake by assuming its head broader than neck or neck thinner than mid body.

Length -
This is the largest Colubrid of India. General length is about 7ft but can grow up to 350cm(11.6ft).

Dorsal body -
Body slender with shiny smooth and keeled scales. Keeled scales present on 4-8 topmost rows mostly on the posterior body. Regular black, yellow and white band like markings present on the whole body according to the color of the dorsal body. These black colored patterns become net-Like on tail side and clearer than mid body. Dorsal body color varies from jet black (Central India and parts of North-East), greenish black, range of brown, yellow etc. Sometimes black colored specimens don’t have any patterns so appear like Cobra.

Ventral body -
Belly color also depends on dorsal body color from pale yellow or white mixed with green, brown, gray, yellow etc. sometimes dark color patches exist on the whole ventral side. Subcaudal scales paired in a zig-zag manner and ends with a pointed tip.

Head -
Head pointed with shiny smooth scales, clearly broader than the neck. Between two lip scales, there is a presence of a blackish color border. Large eyes have rounded pupil. Tongue color purplish-black with darker color on the front side.

Tail -
Long tail typically like other tree snakes with a pointed tip. Blackish reticulations present on the whole posterior body including the tail.

8 Supralabial; 4th & 5th touches eyes; preocular 1; presubocular 1; loreal 1-4 but 3 is most common; postocular 2; temporal 2+2. Maxillary teeth 20-25.
Both smooth and keeled scales in 17/18/19:16/17:14 rows.
190-213; angulated laterally.
Sub Caudal: 
100-146; paired; anal divided. Hemipenis extends to the 10th-12th caudal plate, not forked.
Rat snake is a diurnal species and show activity at day and evening time only. Remains hidden in dark and silent places like rat holes, termite mounds, wood caves, under rocks etc. during night time. Lives in almost all kinds of habitat due to its tendency to survive in tough conditions; this includes urban area, dense & open forest, hills, agricultural lands, scrubs, rainforest etc. Prefers wet surroundings during summer (shows semi aquatic behavior few times), while dry during monsoon. Habitat include hills, open and dense forest, hills, grassland, wetland etc.
Feed on a variety of prey mostly on rodents and toads; also feeds upon birds, small mammals, other snakes, all kind of lizards, eggs etc.
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