Chekered Keelback (Xenochorophis piscator)
English- Checkered Keelback, Asiatic Water Snake | Gujrati- Dendu, Dendvo, Pani no sap | Hindi- Paani wala saap, Dendu, Panial | Marathi- Divad | Malyalam- Neerkoli, Thannipampu,Kulamandali, Thanneer pampu, Neerpampu, Olla Pulavan, Neer Mandali | Oriya- Dhanda
Distribution - All over India.
Status -Very Common. Most common Colubrid.
Length- Adults measure approx. 3.5ft(adult) but can grow upto 5.7ft.
Dorsal body- Body shape stout with keeled scales on the top and smooth on side dorsal body. Scales have 2-4 different colors in a single specimen, generally glossy green dominant with blackish, brownish, reddish and yellowish color spots. Specimen from Maharastra have blackish color dominant with yellow-white patches. Juveniles have clear olive green color with black patches and yellow patch row in top scales.
Ventral body- Belly entirely yellowish white(most commonly) or white mixed with red or green(rarely). Subcaudal scales paired in a zigzag manner, their color is similar to ventral scales but sometimes can be darker than ventrals.
Head- Head tringular with smooth shiny scales; broader than neck. Color shiny olive green or brownish mostly. Two black streaks starts from eyes and ends on posterior lip, the color of area between these stripes is lighter than rest of head part. Two yellow-black patches present on inner side of parietal scales very close to each other; may be absent in adults. Eyes have rounded pupil; tongue color purplish-black.
Tail- The tail also has highly keeled scales. Normal as typical range with pointed tip. Tail color almost same like rest of the dorsal body but usually without other color patches.
Key Characters for Identification
- Body greenish in color with Black patches in whole dorsal surface. Usually adults have lower lip of yellowish color.
Look alikes- Cobra(in low light), Rat Snake, Green Keelback(on shedding), Olive Keelback, Smooth Scaled Water Snake.
9 Supralabials; 4th & 5th touches eyes while 6th SL is excluded clearly by 3rd postocular; 1 Preocular; 1 Loreal; 3 Postocular; Temporals 2+2 or 2+3.
Scales keeled with 19-19 in front body while 17-17 on posterior dorsals.
122-158; Anal divided or undivided.
Behavior- Chekered keelback can be active all the time but found to be more active in the evening and early night. Lives around any type of water body including lakes, river, pond, sewer line, logged water in agricultural lands, wells; can survive in moist surrounding without any water supply.
Feed variety of animals including fishes, toads & frogs(mostly), small mammals, lizards, other snakes; juveniles feeds on insects and tadpoles also.
Behavior alert and aggressive. Always bite when disturbed or provoked. On provocation they flatten their neck in “Cobra Style”, at some height above the ground and creeps in a jumpy manner in uncertain direction to get temperory hiding place.
Reproduction - Mating is from winter starting to middle of summer. Female lay upto 90 eggs in dry and moist place. Maximum hatchlings observe during late June to end of July.
Chekered Keelback is probably the most common species in rescues. Its adaptation to live with humans is very high, can live in any kind of water supply in urban area including sever lines also. This is the only species which could be found deep inside the urbanized colony which is due to the fact that it can survive in unhygienic conditions(strictly unsuitable for other snakes) also. Though it is totally harmless species but as its rescue cases from inner parts of city are very common. In such cases rescuers have to find out appropriate new places outside the city. Specimen of larger size can be released(not in bunch) outside the city in natural water bodies like lakes and pollution free water stream.