CLASSIFICATION OF NATRIX : WATER SNAKE
PHYLUM :- CHORDATA (Notochord, dorsal tubular nerve cord present and gill slits present )
Group :- CRANIATA ( Definite head. Cranium with brain present )
Sub-phylum :- VERTEBRATA ( vertebral column present)
Division :- GNATHOSTOMATA ( Jaws and paired appendages present )
Super class :- TETRAPODA ( Paired limbs, lungs, bony skeleton and cornified skin)
Class :- REPTILIA ( Scaly vertebrates with right and left aortic arches. Single condyle, pulmonary respiration. Embryo with amnion and allantois ).
Sub-class :- DIAPSIDA ( Skull with two temporal openings separated by postorbital and squamosal ).
Order :- SQUAMATA ( Lizards and snakes with horny epidermal scales or shields. Quadrate bone movable. Vertebrae procoelous. Anal opening transverse).
Sub-order :- OPHIDIA ( Snakes. Limbs, feet, ear openings sternum and urinary bladder absent. Mandibles jointed anteriorly by ligament. Tongue slender, bifid and protrusible. Left lung reduced).
Family :- COLUBRIDAE ( facial bones movable, no fang ).
GENUS :- Natrix
Natrix or Water Snake is widely distributed in U.S.A. Mexico, North Africa and India.
HABIT AND HABITAT
It is found near water source, such as rivers, lakes, ponds and marshes, though they prefer relatively quiet waters. They like to bask in the sun so seek areas that are not overly shaded. When they’re done with the sun, water snakes take refuge under flat rocks and logs. . It is diurnal oviparous and feeds on fishes and frogs.
GENERAL CHARACTERSTICS OF NATRIX : WATER SNAKE
- Commonly called water snake. It is non-poisonous. Natrix is the common Indian water snake .
- They should not be confused with sea snakes, which live primarily or entirely in marine environments.
- Body is covered with epidermal scales and contains chess-board like black spots. Body divided into head, neck. trunk and tail. Ventral surface abdominal plates.
- The common water snake can grow up to 135 cm (4 ft 5 in) in total length (including tail)
- Head is distinct and comprises bulging eyes, slit-like mouth and bifid tongue. Head scales are large called as shields. Belly scales plate-like, while side scales smaller. Bifid tongue protrude between upper and lower jaw.
- Both jaws contain teeth but without fangs. Maxillaries horizontal forming most part of upper jaw.
- Facial bones movable. Squamosal loosely attached to skull. Tympanum absent.
this snake contains chess-board like black spots and above features, hence it is Natrix or Water Snake.
- Book of Practical Zoology VERTEBRATE by S.S.LAL – Rastogi Publications.
- SOURCES OF IMAGES – https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.raritanheadwaters.org%2F202 0%2F06%2F05%2Fcreature-feature-northern-water-snake%2F&psig=AOvVaw3CAs6nBqGdM0YAFQKLXCsN&ust=1602684954389000&source=images&cd=vfe&ved=2ahUKEwj-lbXs4LHsAhXAEbcAHTozC9AQr4kDegUIARD7AQ