TROPIDONOTUS-NON-POISONOUS SNAKES

TROPIDONOTUS-This is common snake found in pond,or also called grass snake.It feeds on frogs,toads,fish. Body is stout,cylindrical and 1 meter long.Body is rough due to keeled scales. Colour is yellow or brown with black spots. e.g T.quincunciatus,two black streaks run behind from each eye. It is not harmless.
LYCODON-The maxillary fangs are not grooved but adapted for catching these slippery lizards.Colour is brown above with white cross bars all over the body.e.g wolf snake grows to 60 cm.The ridge runs along the sides of abdomen and tail.Incolouration it mimics the poisonous krait, but is non-poisonous.
DRYOPHIS-The whip snake has excessively slender body like the cord .Head is narrow,long with a tapering snout.Pupil is horizintal.posterior fang like maxillary,teeth is grooved.Having green colour.It is viviparour and feed on small birds and reptiles.The non-poisonous snake its saliva is weakly poisonous so they was able to kill small animals.

POISON APPARATUS-SNAKE

The poisonus snake include <1>poison gland <2>ducts <3>fangs <4>muscles.
<1>POISON GLAND-The sac like poison gland is situated  on either side of upper jaw, below the eyes .The are modified superior labial or parotid glands. The gland be small and oval ,large or tubular .The gland is sticky ,encapsulated with fibrous connective and mostly covered by a fan-shaped constrictor muscle,as temporal or masseter.Its stretching during biting squeezes poison from gland into its duct.
<2>POISON DUCTS-The poison duct leads anteriorly from poison gland to the base of a poison fang to enter its groove .
<3>FANGS-The fangs are certain specialized teeth attached to maxillary bones.Fangs are long,curved ,sharp and pointed.They use hypodermic needles for injecting poison into the body of victim.The fangs occur in poisonous snakes.
<a>SOLENOGLYPHOUS-The large functional fang occurs on the front of each maxilla.The base is covered with reserve and developing fangs.The fangs are movable and turned to lie to the roof of mouth .The hollow poison canal lined with enamel runs through the fangs opening at the tip.e.g vipers,rattle.
<2>PROTEROGLYPHOUS- The front of maxillae are permentely erect, the fangs are small. Each fang is grooved all along its anterior face.e.g cobras,kraits, coral snakes and sea-snakes.
<3>OPISTHOGLYPHOUS-The fangs are small,lie at the back of maxillae .e.g family colubridae.

UROPELTIS-NON-POISONUS SNAKES

It is called rough-tailed snake.It is similiar to blind snake having a short tail ends flat rough shield.Teeth are found in both jaws.It is viviparous. e.g uropeltis grandis.
TYPHLOPS-Having a size of 175-180 cm long.It looks like earthworm,hence the worm snake.Tail is blunt. Body scales are small,uniform and semicircular. Blunt scales is covered with large shield. Eyes are vestigial and hidden beneath shing scales,called as blind snakes. Teeth are abesent in lower jaw. It is harmless and feeds on insect larvae and termites.e.g T.braminus and T.thurstoni.

GIRAFFA

Giraffe,giraffa camelopardalis,tree-studded grasslands of E.Africa.It is the tallest the living animals reaching a height of 6 m above ground.Head in both sexes carries 3 to 5 small bony horns covered by velvety skin. It is prehensile tongue can extend up to 50 cm to eat leaves of trees. Giraffe is fast enough to outrun most of its enemies. It cannot make sound.

HEMIRHAMPHUS,DIODON

Family hemirhamphidae,order beloniformes. found in rivers and ponds of w.bengal and orissa,called haif-beaked fish.lower jaw projected beyond the upper jaw,both having pointed teeth.
DIODON-family diodontidae,order tetraodontiformes. similar to tetradon in structures and habit aiso called as porcupine fish. occurs from red sea through out indian seas to pacific ocean.

CLARIAS,HETEROPNEUSTES

Cat fish clarius batrachus  has accessory respiratory organs.These are in the formof two much branched tree-like dendritic or arborescent organs developed inside suprabranchial cavities one on either side above the gill chambers. The cavities and the organs are covered by vascular mucous epithelium and functions as lungs. The fish periodically reaches watter surface to renew air.
HETEROPNEUSTES-This catfish has a pair of long tubular and dorsally situated air sacs arising posteroorly from gill chambers and extending almost up to the tail.They are highly vascular .The air is drawn in and expelled out through pharynx.

KRAITS-POISONOUS SNAKES

The poisonous snakes are cobras, kraits,pit less vipers  pit vipers,sea snakes and coral snakes. Their tails are cylindrical teeth modified into fangs.Their tails are cylindrical except in sea snakes.Head are covered into shields and ventral shields cover the entire width of belly .