Structural organisation of Animal
FROG (Rana tigrina)
Phylum: Chordata
Class: Amphibia
Order: Anura
Genus: Rana
Species: tigrina
The most common frog found in India is the Indian bullfrog.
It is the largest frog and is named as bullfrog because of its large size and
loud call.
Indian bullfrog is found in fresh water marshes, ditches, ponds, and shallow
lakes.
30
They undergo aestivation (summer sleep) in summer and hibernation
(winter sleep) in winter.
They are carnivorous (feeding upon other animals, insects, etc.),
poikilothermic ie. the body temperature changes with environment.
They develop protective coloration to camouflage, ie., to hide in
surroundings.
The most common species is known as Rana tigrina (Indian bull frog).
The scientific name of common toad is Bufo melanostictus. Frogs
exhibit sexual dimorphism.
Male and female are distinguishable externally only during breeding season
when the males develop nuptial pad in the first digit of forelimbs.
Vocal sacs are well developed in males so they produce louder sound as
compared to the females which are devoid of vocal sacs.
The vocal sacs help to produce mating calls.
Total number of bones is 153.
External Morphology
Skin is made up epidermis and dermis. Mucous glands are present in the
dermis and their ducts open at the surface.
, Blood capillaries and pigment cells (chromatophores) are present in the
dermis.
Skin is without scales or any other cover or exoskeleton.
Body is divisible into head and trunk, neck is absent. The trunk is
provided with a pair of fore and hind-limbs. The hind-limbs are much
larger and muscular than the fore-limbs. Fore-limbs end in four digits and
the hind limbs end in five digits. The digital formula of fore-limbs is
02233. The digital formula of hind limbs is 22343.
Shank or crus is associated with hind limbs.
Sexual dimorphism:
By inflating these repeatedly with air from the lungs, the males produce
a loud croaking sound meant to call the females for copulation
(amplexus).
The sound is actually produced by a pair of vocal cords in the larynx; the
sacs only increase its pitch, like resonators.
The females produce a low pitch sound by their vocal cords alone.
The forelimbs in both male and female frogs bear small articular pads
dorsally at the joints of digits, but the males also possess a special
nuptial, copulatory or amplexusary pad on ventral side of the first finger
of each forelimb.
Normally, these pads appear merely as rough patches but during
breeding season, these become thick and sticky.
In amplexus, the male strongly grips a female under her armpits by
means of these pads.
FROG (Rana tigrina)
Phylum: Chordata
Class: Amphibia
Order: Anura
Genus: Rana
Species: tigrina
The most common frog found in India is the Indian bullfrog.
It is the largest frog and is named as bullfrog because of its large size and
loud call.
Indian bullfrog is found in fresh water marshes, ditches, ponds, and shallow
lakes.
30
They undergo aestivation (summer sleep) in summer and hibernation
(winter sleep) in winter.
They are carnivorous (feeding upon other animals, insects, etc.),
poikilothermic ie. the body temperature changes with environment.
They develop protective coloration to camouflage, ie., to hide in
surroundings.
The most common species is known as Rana tigrina (Indian bull frog).
The scientific name of common toad is Bufo melanostictus. Frogs
exhibit sexual dimorphism.
Male and female are distinguishable externally only during breeding season
when the males develop nuptial pad in the first digit of forelimbs.
Vocal sacs are well developed in males so they produce louder sound as
compared to the females which are devoid of vocal sacs.
The vocal sacs help to produce mating calls.
Total number of bones is 153.
External Morphology
Skin is made up epidermis and dermis. Mucous glands are present in the
dermis and their ducts open at the surface.
, Blood capillaries and pigment cells (chromatophores) are present in the
dermis.
Skin is without scales or any other cover or exoskeleton.
Body is divisible into head and trunk, neck is absent. The trunk is
provided with a pair of fore and hind-limbs. The hind-limbs are much
larger and muscular than the fore-limbs. Fore-limbs end in four digits and
the hind limbs end in five digits. The digital formula of fore-limbs is
02233. The digital formula of hind limbs is 22343.
Shank or crus is associated with hind limbs.
Sexual dimorphism:
By inflating these repeatedly with air from the lungs, the males produce
a loud croaking sound meant to call the females for copulation
(amplexus).
The sound is actually produced by a pair of vocal cords in the larynx; the
sacs only increase its pitch, like resonators.
The females produce a low pitch sound by their vocal cords alone.
The forelimbs in both male and female frogs bear small articular pads
dorsally at the joints of digits, but the males also possess a special
nuptial, copulatory or amplexusary pad on ventral side of the first finger
of each forelimb.
Normally, these pads appear merely as rough patches but during
breeding season, these become thick and sticky.
In amplexus, the male strongly grips a female under her armpits by
means of these pads.
