Whales and dolphins are the aquatic animals. They are distributed in the aquatic habitat. Whale is the perfectly marine in habitat where as the dolphin is also found in fresh water as well as in marine habitat.  Both whales and dolphins have got stream-lined body with the paddles and flippers as the locomotary organs. They are excellent divers in the aquatic habitat. Whale is the largest animal of nature. But Dolphin is considered to be the intelligent mammal.They show the secondary aquatic adaptation i.e. they were primarily adapted in the terrestrial habitat but in the course of evolution they migrated from the terrestrial habitat to the aquatic habitat and started tom live permanently in the aquatic habitat.

Animals of spiritual value

Animals are valuable from the different point of view. Some animals of nature are of high spiritual value. There are many animals which are considered to be spiritually valuable  and even worshipped from time to time in the special occasion. Some of such animals are elephants, tiger, lion, Garuda, fish, snake, mouse etc.
 Elephant which is the very big animal which is spiritually valuable. It is considered to be the incarnation of Lord Ganesh. Its trunk is comparable to the trunk of Lord Ganesh. It has been the belief that if the soil inside the feet of elephant is touche dor kept in home it will do good harmony in the home. It is the good sign which helps to eliminate evils around the home.
Another important animal of spiritual value is the tiger which is considered to be the bahan of Goddess Durga. She had won the victory over Demon Madhukaitab by riding over the tiger and fighting with the fearful monster. Similarly, snake has its own value in spiritual world. Although snakes are fearful animals of natureand have frighetening appearance, snakes are considered to be the incarnation of God and worshipped as Nagraj, i.e. the king of snakes They are worshipped on the occassion of Nagpanchami.

Octopus, the well known predicting animal of nature.

Octopus, is the common marine animal which comes under the phylum mollusca and class cephalopoda. It is the very popular animal in forecasting and predicting the future events. The general characters of this animals are the following:
It has the soft body which consists of the skeleton which is made up of calcium carbonate. Its locomotary organs are situated in the head region, It has the sucking organs in its body. What is particular about octopus? One of the peculiar of octopus is the capacity of this animal to predict the future events. For example, Octopus paul was the very popular octopus which was born in England and brought to Germany. It was kept in the tank and given the mussel as the food. Then the flags of the concerning countries were placed in the tank. Then, the observation was done by looking the choice of octopus Paul to choose the box with flag of the concerning country. The Octopus Paul's prediction became correct as its choice for Spain's flag as the future winner was materialized. Then it was found to be dead in the month of October in the same year.

Hippocampus, a peculiar bony fish of sea

Hippocampus  is the peculiar bony fish of marine habitat. It is quite different from the other remaining bony fishes. Being a bony fish it exhibits all the general characters of the other bony fishes such as presence of body covering with smooth cycloid and ctenoid scales, having a gill covering called operculum, and the skeleton whichnis made up of true bone instead of cartilage. The particular characters which make it quite different from the remaining other bony fishes are that it is the fish which is more or less similar to the horse. Its snout is very much similar  to the appearance of a horse. and it always lives in the sea. So it is known as sea horse. The other peculiar character of this fish is the swimming method of this fish. It has the capacity to swim vertically. i.e. up and down. Other bony fishes use to swim horizontally but this fish  swims vertically , up and downward movement. Another important character of sea horse is that it is adapted to hold the twigs  and so it is adapted to resemble with the twigs of the branches of the tree. Its tail is prehensile. So, it has become the peculiar fish of marine habitat.

Butterfly, the beautiful animal of nature

Butterfly is the well-known invertebrate of animal kingdom. It belongs to the class insecta of the phylum arthropoda. Being the representative animal of phylum arthropoda, it exhibits all the general characters of phylum arthropoda like body covering with the exoskeleton of chitin, jointed appendages in the body, distribution in the air and other terrestrial habitat but wide capacity of tolerance to survive even in the cold climate of the peak of the mountains. Butterflies are of different colors and they use to live in the gardens especially during the day times.
  Their body can be divided into the three parts: they are anterior head, middle thorax and the posterior abdomen. Head consists of a pair of compund eyes, a pair of clavate antennae and mouth parts. They have the siphoning type of mouth parts which is adapted for sucking up the nectars of flowers. This type of mouth part consists of a well-developed proboscis which is used to form a sucking tube for collecting nectar of flowers. They have one pair of wings which lie vertical in position when they are at the resting stage.They remain active during the day time. Such animals are called diurnal animals.

Amphibians of Nepal

Amphibians of Nepal are of various types. There are 43 species of amphibians reported from Nepal according to (Shaha,1995) and Tiwari (2004).Shaha and Tiwari reported 53 species of amphibians from Nepal in "Herpeto fauna of Nepal: A conservation companion". They are of considerable aesthetic and economic importance. Some of them are found in great abundance in the remote hills and plains of Nepal. Some formerly common have become increasingly rare due to habitat destruction, pollution of the streams, lakes etc where they live. In the villages , the frogs are extensively hunted for commercial purposes. Some tree frogs are caught and kept in earthen  pots and marketed in the living form.The killed frogs are dried or smoked and are sold in the off season.
 Purplw Caecilian (Ichthyophis glutinosa) is a burrowing amphibian reported from the locality of Butwal  area. It is the only representative genus and species from the order Apoda.
 Himalayan newt or salamander (Tylototrion verrucosus)  commonly called pani kukur is the only urodel found in Arun valley of Nepal.

Giardia, the endoparasite

Giardia is one of the endoparasite which lives inside the alimentary canal of men and other vertebrates. This is the unicellular protozoan which comes under the class ciliata. Giardia lambla or Giardia intestinalis is a parasite in the small intestine and colon of men. It remains attached in masses to the mucus membrane from where it absorbs food consisting mainly of mucus.Occasionally the parsite invades the bile ducts and gall bladder.Other species of Giardia are parasites in the intestine of vertebrates.
Giardia has an elliptical body which is bilaterally symmetrical. The dorsal side is convex, but the ventral side is flat or may be convex.. The anterior end is rounded and the posterior end is tapering.In the anterior half of the ventral surface is a concave sucking disc for attachment to the host.There are two vesicular nuclei and four pairs of long flagella.Passing through teh cytoplasm from the anterior to the posterior end are two parallel ,flexible, needle like axostyleswhich support the body. The nuclei are attached by fibrils to the axostyles. Just behind he sucking discs is a deep staining parabasal body.
   Giardia prevents absorption of fats by the host inside the body of which it lives. The unabsorbed fat causes diarrhoea.It also forms oval thick-walled cysts. Cyst undergoes the division of nuclei inside it as a result of which four nuclei  are formed. The cysts pass out with the faeces and remain infective for about ten daysor more. The parasites can be removed by the treatment of the disease by the help of antimalarial drugs like chloroquin ans antrebrin.

Dinosaur

Dinosaurs are the giant reptiles of prehistoric times. The geological survey of India has brought to light fossil remains of dinosaurs at Siranatham at Kallamedu in Tiruchirapalli district of Tamilnadu. These great dinosaurs which ruled earth for about 150 million years ago. came extinct 65 million years ago.There extinction was probably due to their great size and small brains which prevented them  from effectively competing with mammals.
 As the dinosaurs were the huge bodied dominant animals as frightening as any animals with their fearful appearance every body especially children  are afraid of their name. They always use to ask the different questions regarding dinosaurs how they are,  what they do, what they eat, where they live , How often they us etc appear in the different forms , how to see them without fear etc etc. Any way dinosaurs are the fearful reptiles like the huge lizards which were flourishing in the mesozoic era of the earth's history. They were dominating all the animals of nature including the human beings

Spiritual value of buffalo

Buffalo is one of the animal which has also the spiritual value. It is the huge bodied animal with black colour. Body is covered with hairs. It is herbivorous in food habit. It has one pair of horns which are used as its defensive organ. Buffalo sometimes uses butting its head with other elephants. Although elephant is domesticated mainly for milk and milk products but it is also used for ploughing the land before cultivating crops. Buffalo is also used to run the vehicles like bailgada It is also used for running the vehicles.
So far as the spiritual value is concerned, buffalo is also considered as the vehicle of Yamraj, the God of death. According to Hindu mythology, Yama, the God of death, goes to his sister Yamuna and stays with her as a guest for five days. In Nepal, Deepawali or Yama panchak festival is celebrated as Tihar festival. During this festival due respect is paid to Yama by the people. During this festival buffalo is also paid due respect as the ehicle of God Yamaraj.

More about elephant

Elephant has got different names from the religious point of view. These names are naga, dvipa, padmin , Hastin etc. So, the different epithets have been given to the elephant. It is so called naga because it freely moves in water as well as on mountains and jungles. The name Dvipa which means the twice drinking i.e. drinking both from the mouth and the trunk. It has the habit of eating lotus. Due to this habit its name is given as Padmin that means lotus.It is associated with lotus in several representations. It is also given the name of 'Hastin' as it is born from teh hands of God rahma.
          According to legend, thefirst elephant was produced from the cosmic golden egg or Hiranyagarbha. Brahma took two halves of the broken shell in his hands and breathed life into them. Out of the shell came Airabata and seven other male elephants and from tehsecond shell sprang eight female elephants. These male and the female elephants started reproducing. Attached to this legend, an elephant is also called Hathi in Hindi and Hatti in Nepali. The eight male elephants became the bahana of Astha dikpalas or guardians of eight directions.

lElephant is also one of the majestic animal which is also important from the spiritual point of view along with its lots of other importance.These majestic animals are greatly associated witht he myths, mythologies and symbolisms of Hinduism and Buddhism in the countries like Nepal and India.
Its habitat: Its habitat is the jungle of herbs,where it goes cautiously moving breaking through all obstacles, protecting its calves from dangers, roaming over hills ,swimming across rivers and lakes in spite of its huge body. It possesses enormous strength and size. It imparts decorative grandeur to the pomp and pageantry of Indian and Nepalese life It has multifarious characteristics which has led to their representation in arts and literature. Its a fact that among the large animls of nature only the elephant survived in the struggle for existence. Its survival is not only due to its intelligence but due to its qualities of being associated and domesticated with men. It means it has the power of adaptation which has made it successful in the different types of adverse natural condition.The elephant enjoyed great prestige and it finds mention in various contexts in the epics i.e. in arthashastra of Kautilyawhere its force has been referred to the fabulous strength of kings.

Monkey ,the familiar animal of nature

Monkey is the familiar animal of nature. It is found almost all over the world. Monkeys are distributed in the forest areas. But sometimes they come near the human dwellings. They live in groups.The zoological name of monkey is Macaca mulatta. That is its genus is Macaca and species is mulatta. Monkeys have the general characters like that of human beings in many of the points which are as follows:
- They have the body which is covered with hairs.
- They have one pair of external ears known as pinna.
- They have two pairs of limbs, one pair of forelimbs and one pair of hind limbs.
- They have the four - chambered heart.
- They are also viviparous animals i.e.they do not lay eggs but give birth to the young ones.
-They are warm-blooded animals. i.e. they keep the body temperature constant all the year round.
  Monkeys are well known as the naughty animals of nature. They have the herbivorous food habit. They show the very good example of group behavior.

Porcupine, as the sacred animal

Porcupine is also one of the sacred animal of nature. It is directly not associated in religion as the vehicle of any God and Goddess. But still it has some spiritual value.
Porcupine is an animal which belongs to the order rodentia of class mammalia. It comes under phylum chordata. It is in the same group in which the cat belongs.
Habitat: Porcupine lives in the deeply wooded areas of the forest. It is very easy to kill porcupines and its meat is also tasty. Porcupine has the habit of girdling trees. The quill of porcupine is found to be used for different porpuses: For example, In the investiture of the sacred thread ceremony (upanayan) the top knot of the brahmachari (celibate) is separated into three portions with the help of a quil of porcupine. Another use of the quill of porcupine is that a pregnant woman observes a ceremony called simanta ceremony in which the prtings are separated with a quill of porcupine.Among the newar caste, there is the custom of performing the primary marriage ceremony called ihin when young girls of pre puberty age are symbolically married to a bell fruit which is the personification of God Narayan.During this ceremony, a quill of porcupine is inserted in the hair of the girl.

Parrot, the beautiful song bird of nature

Parrot is the beautiful animal bird of nature. It is included under the class aves of phylum chordata. being the birds parrots show the general characters of birds  which are as follows:
1.They have the stream-lined body
2. Body is covered with feathers which provide the   good insulating mechanism to their body.Feathers help them to decrease the body weight as well.
3. Forelimbs are modified in the form of wings which help them to fly in air.
4. They have the hard and curved beak which are white or red in colour. Beak halps them to tear the nuts and hard fruits.
5. The colour of the body is very attractive with :amixture of green and lemon yellow which looks brilliant tot eh viewers.
6. Their tail is cylindrical and help them to balance the body in air during their flight.
Parrots as the beautiful cage bird: Parrot is the beautiful cage bird. It has the sweet voice and it can imitate certain words of human beings. So people use to keep them inside the cage and use to hear their sweet song time to time.
Role of parrot in ecosystem: Parrot is not only the beautiful animal of nature but also has the important role in balancing the natural system called ecosystem. Being the herbivorous bird, it is included under the primary consumer in the food chain of ecosystem. They help to balance the number of producers in an ecosystem which is their role of balancing the ecosystem. As a whole they are helping to protect the environment by balancing the ecological system.

The Dragon, a symbolic animal

Dragon is a fabulous, winged fire breathing monster which is scaly- armoured . Dragons are symbolic animals because they are represented in various paintings, weaving- works, sculptures and wood works.They are also represented on the sides of the temples. For example dragons are sculptures in the Kalmochan temple at the Bagmati river and the Akash Bhairabha temple which is situated in Indrachowk of Kathmandu city.Hindus and Buddhists believe that dragon is associated with water. They believe that water sprout is regarded as a dragon as it can never be seen fully because its head or its tail always remains invisible.It is also regarded that a dragon and the tiger are mutual enemies. Buddhists regard that if a tiger's bone is thrown into a dragon's well, the rain will intervene and a fight takes place between them.It is also a common belief about the dragon that if the dragon moves there is always rainfall.
                 Dragons are usually represented half feline , half reptilian  with dorsally situated spikes and pin wined wings. However some people believe dragons to be winged lions and not the dragons.So it can be said that dragons are the animal symbols which can not be described in any one form but they show the mixed characters of the different animals. They are master pieces of carefully related forms. Sometimes horns are also depicted and fire juts out of their mouths. Their wings are highly styled and neck is powerful and thick.
The body is very muscular with swelled up chest. The treatment of the muzzle is excellent. They look very terrible in  appearance. The pre -paws are pointed in front. Phallus is highly erected to depict its fierce attitude.The dragons are bulky with square  block -like heads. The monster is in a roaring condition and has a forward -striding attitude. Dragon's figures are commonly woven on the carpets  which are manufactured in Nepal.

The Dragon, a symbolic animal

Introduction of squirrel

Squirrel is natures one of the beautiful animal. It comes under the phylum chordata. It belongs to the class mammalia. Squirrel as in the figure, shows the elongated cylicdrical bodywhich is covered with hairs. Its body

consists of the following parts:
a. head b.Neck.c. Trunk and d. Tail.
Head consists of the paired eyes , a pair of pinna or external ear, and a snout which is protruded anteriorly. At the tip of the snout , there is the mouth.
Neck: It is the second part of the body of squirrel and it lies in between the head and the trunk.
Trunk: Trunk is the third part of the body of squirrel. It lies just posterior to the neck and anterior to the tail. Trunk is the longest part of the body of squirrel and it is comparatively the wider part also. On the ventral side of the trunk two pairs of limbs are found, they are fore limbs which are anteriorely located paired limbs and the next pair of limbs are the hind- limbs which are longer than the fore- limbs.d.
dTail; It is the last part of the body. It is not very long but short and bushy.
Whole the body is covered with hair which is one of the important character of the class mammalia.
      Squirrels have the alternating longitudinal stripes of alternating black and brown colour on the dorsal side of its body which is the identifying feature. They are herbivorous animals and have the strong grasping power. They climb on the trees and can leap very fast to the long distance.
Distribution: It is distributed in the most ofthe tropical countries of South Asia like Nepal, India, Bangladesh etc.

Swan, the semiaquatic animal of nature.

Swan is also known as Hamsa. It is the long -necked bird with a red beak and a snow-white body. It is capable to fly high. It belongs to the migratory kind of bird. Its famous living place is Manosarobar , a famous big fresh water lake located in Tibet. This lake is the most sacred lake by both the Hindus and Buddhists and is situated against then backdrop of famous Kailash mountain.
According to Buddhists, in one of his previous birth, Buddha was a golden goose i.e. a kind of Swan He was helping a Brahmin  and his family by providing a feather daily. but the Gee Brahmin one day took off all the feathers which turned white and were of no value.
According to Hindus , Swan is the vehicle of Lord Brahma. Some scientists also consider the bird as the incarnation of Kubera, the Lord of wealth. Bannerjee write that later on the Hansa became the vehicle of Goddess Saraswati.Saraswati is the Goddess of learning.
 Anyway the appearance of a white Hansa or evena white bird over the head is considered to be an auspicious sign. When Budha got enlightenment, white birds similar to Hansa flew over him. Similarly when he descended fromTushita heaven or when he crossed the Niranjan river , white birds flew over the head of Buddha.

How do animals remove their excretory wastes?

Animals perform the different systems from the from the different organs. Excretory system which is found in animals as one of the vital systems of the body is the system which helps animals to remove the excretory waste ,materials from their body to out side. The organs which help in excretion are known as the excretory organs.The main excretory organs of the vertebrates are known as kidneys. Kidneys are paired structures which are bean-shaped and located in the dorsal wall of the abdominal cavity. Human kidneys are not located in the same level, one is located a little bit above than the other. Anyway kidneys are the very important organs of the animals body. They have two important functions:
One is the filtration of blood and the other is urine formation. For that purpose each kidney has its two important functioning parts: The Bowman's capsule- which helps to filter the blood and pass the useful substances present in the blood back to the body cells and the other important functioning part of the kidney is called the uriniferous tubule. It is the elongated tubule of varying diameter which helps to form urine.

Facts about Sharks

Introduction : Sharks are the animals which are included under the phylum chordata and the group vertebrata. They are in the series pisces. i. e. fishes.
Sharks do not have the well -developed skeleton like other fishes becaus  other fishes have the well developed skeleton which are made up of bones. But in sharks, the body is supported by cartilaginous skeleton that means  the skeleton is not made up of bones but of cartilage. Cartilage is not as hard as the bone and it is made up of the material called chondrin. That is the reason the sharks are also known as the cartilaginous fish.Sharks have the muscle tissue made up of cartilage and it makes the fish to be weightless in water.They are adapted excellently to live in water. They have the rough type of skin which is covered with the small toothed scales, which overlap like roof tiles to achieve streamlining and speed in water. Sharks can find their prey over distances of up to 1000 metres. They have ultra sensitive receptors in their snout and lateral sensorial system which detect the slightest vibration in water.They also have the reflective mechanism in their eyes which allows them to distinguish objects in dim light.

Whales and dolphins

Introduction: Whales and dolphins are the animals which are included under the order Cetacea of class mammalia. They come under the phylum chordata.
Habit and habitat : Whales and dolphins are found in all seas. Few of them also live in rivers and lakes. They are carnivorous and predaceous in habit. They are found to be swimming with great strength.
Structure : Body of these animals is fish -like and stream-lined. Scales are lacking. So, the body is naked. But a thick layer of fat is present below the skin in subcutaneous layer. It is also known as blubber . Nasal apertures are found on the top of the head region. Caudal fin or tail fin is expanded horizontally expanded. Their dorsal fin is fatty. They have minute external ear. But pinna are absent. Eyes are very small and are situated at the angle of the mouth. Their body size ranges from small five feet to hundred feet in length and about 150 ton in weight. Whales are the largest animals in the animal kingdom. They are even larger than the dinosaurs. These animals are descended from the land living ancestors and use to breathe air by coming to the surface frequently.

Rhinoceros unicornis

Rhinoceros unicornis is one of the huge animal. It belongs to the order perrisodactyla of class mammalia. This is the huge bodied mammal. Its distribution is in African continent as well as in the Asian continent. In Asia this animal is found in the countries like India, Nepal and Nepal. It is also found to be distributed in the south east countries like Indonesia , Sumatra etc.
Rhinoceros has the huge body with tons of weight. Its body is divisible into head, neck. trunk and tail. Head hinregion consists of special horn which is epidermal in origin. The name Rhinoceros unicornis signifies to the presence off single horn in its head region. Some rhinoceros have two horns in the head region. They are known as Rhinoceros bicornis. Rhinoceros bicornis or two horned Rhino are found to be distributed in a the African continent but not in Asian continent. But single horned Rhino is distributed in Asian continent but not in Africa.
Single horned Rhino which is distributed in Asia is found mainly in the dense forests of the tropical countries like Nepal.

Introduction of amphibian animals

Amphibian animals are those animals which live in the two different types of habitat, the aquatic habitat and the terrestrial habitat or land. These animals need the aquatic habitat at the time of breeding season. Some amphibians are more terrestrial than others. Toads are the amphibians which are more terrestrial. Other amphibians are more aquatic than other amphibians. For example frog is the amphibian which is more aquatic in habitat. There are other amphibians which have tail in their body and which swim in water y and look like the fish or like the larva of frog. Anyway amphibian animals have the important characters like :
- They have stream-lined body shape
- They have thin and moist skin which helps them in cutaneous respiration
- They also respire through the lungs when they are in the adult stage and when they need more oxygen like in breeding season and in the time of high metabolic rate.
- They have the body colour which harmonise them in the surrounding environment-

Introduction of 'Dipnoi'

Dipnoi are also called lung fishes. They have the peculiar character. They first appeared in the mid Devonian deposits, flourished in Permian and Triasic period and became rare. They are actually the  fishes having the skeleton made up of bones . They belong tot he subclass choanichthyes. Actually all the fishes use to respire with  the help of gills but the most interesting and peculiar character of  these fishes is that they have lungs by which they breathe in oxygen during respiration. The living Dipnoans are represented by three genera only. These show the discontinuous distribution. These genera are the following:
1.Protopterus from Africa, 2. Lepidosiren from South America and 3. Neoseratodus from Queensland - Australia.
Dipnoi are so known as lung fishes that they have air filled bladder like structures in their body called air bladder which act as lung. These fishes also possess gills. So, these fishes exhibit the double mode of breathing, i.e. breathing from gills and breathing from lungs or air bladder.

How animals communicate ?

Animals use different methods to communicate with one another. Dogs use to bark and show their communication to their fellow dogs. Mouse vibrates its tail so as to communicate with other mouse. Bee which are the insects use to produce a unique sound to give the signal of presence of some sweet fragrance of flowers in a particular direction. Crows and other birds produce the special sound to give the signal of communiacation with other birds.  Parrots make the sweet call as a method of communication. The communication of animals is for the purpose of giving signal to their own fellow species  and the other purpose is to give signal to the other species and to human beings also. communication of animals is usually nonverbal. Some animals use to communicate just by their body language. They use to make the fast or the slow movement of the body and some times come close to the human beings. Some animals use tom gaze at the other animals and also with human beings. Gazing at a point is also one of the form of communication which is seen usually among the cattles.

Animal behaviour

Definition: Animal behaviour can be defined as the activity of the animals in response to a particular type of environmental stimulus. Animal behaviour is mainly of the two types:
(1) The simple type of animal behaviour and
(2) The complex type of animal behaviour

Simple type of animal behaviour: Simple type of animal behaviour is that behaviour which takes place automatically and without any will. It is also of two types.
 a. Reflexes and b. Taxes
:Reflexes: Reflexes are the animal behaviour which is considered to be of the simple type. It takes place in the higher animals as well as the lower animals. Reflexes can be defined as the automatic activity which occurs without any will. It is also known as the involuntary activity of animals without any will There are different types of reflexes which are- Protective reflexive, anti gravity reflex, righting reflex and the conditioned reflex.
 The protective reflex is that in which the sudden acitivity is shown to protected the stimulated part of the body. For example, sudden withdrawl of one's hand when it touches any hot surface or hot object. In this activity a reflex arc is formed during this type of reflex. This reflex arc involves the different nervous components arranged in a cyclical  pattern. The various nervous components involved in this arc are the receptor organ, sensory neurons, spinal cord, brain, response the motor neuron and the effector organs.

What is animal adaptation?

Animals adjust themselves in their habitat by making the body structure suitable according to their environment. This adjustment of the animals in their environment is known as animal adaptation.
Types of animal adaptation:

(1) Aquatic adaptation
(2) Terrestrial adaptation
(1) Aquatic adaptation: Adjustment of animals in the aquatic habitat by modifying certain structures of their body is known as aquatic adaptation. The structures or features which help them to adjust themselves in aquatic habitat are known as the adaptational features or adaptational structures.
     Following adaptational structures or adaptational features are found int the body of aquatic animals

- Body is streamlined in shape which enable them to live in aquatic habitat
- Fins as the main locomotory organs in aquatic habitat. Fins are also of the different types. They are dorsal fins, ventral fins caudal fins. There are paired fins also which are known as the pectoral fins and the pelvic fins.
The fins help them in swimming mode of life but the caudal fin helps them in balancing the body in water and also for changing the direction while swimming.
Gills- as the respiratory organs are also the adaptational structures which help the aquatic animals to breathe in oxygen the oxygen which is dissolved in water. Such aquatic animals which have gills as the respiratory organs are perfectly adapted in aquaticc mode of life.

prchecker.info

Geometrical ratio of increase or theory of ove production

Charles Darwin, the British naturalist propounded his popular theory of organic evolution which is popularly known as ''Darwinism''. This theory states that there is the tendency of all the animals to reproduce and continue the race. They all tend to increase the number of their species and this increase in numbe rof their species is always in the geometrical ratio. This theory is known as the theory of over production or the theory of the geometrical ratio of increase. In this point of his theory he has given the example of the fast reproducing animal and the slow reproducing animal. In the fast reproducing animals he has given the example of paramecium. In the slow breeding animal he gave the example of the elephant. According to this theory of over production Darwin explains that paramecium reproduces by the process of binary fission in the favourable condition of the year and gives the two daughter paramecia. Paramecium reproduces four times a day by the process of binary fission. and the total number of daughter paramecia formed in one day are sixteen. Inthe same way if paramecium foes on reproducing in this way for one year and if all the off springs produced in one year survive without death then what will eb the result? The result will be that there will be no place for other animals to live in this world. The space will not be sufficient for only paramecium also.But there is the check and balance system also which is going on in nature.

Survival of animals in nature

Animals use to survive in nature in the different ways. They have to face the different environmental conditions in their life time. They are so vulnerable that they have to face the survival problem even in the different season of the year. For example, the cold- blooded animals which are also known as poikilothermic animals have the variable body temperature. They do not have the constant body temperature. Their body temperature fluctuates according to the environmental temperature. When there is rise in environmental temperature, the body temperature of the poikilothermic animals also goes up. Similarly, when the environmental temperature falls below zero during severe cold of winter, the body temperature of these cold-blooded animals also fallsbelow zero. But, the metabolic reactions of the body cells of living organisms can take place only in the suitable temperature of about 20 to 30 degree centigrade. The important physiological processes can go on only in the suitable temperature but if there is temperature imbalance inside the body cells then the metabolic activity of the body is disturbed. So, the cold -blooded animals have to face the survival problem in each winter season of the year. Most of them which can not escape the severe cold temperature of cold winter die in the winter season. But the warm-blooded animals have at least the constant body temperature all teh year round. They don't hav eto face the survival problem in each winter. It is not a big problem for them to ace the winter. But some cold blooded animals have adapted their temperature variation by means of the physiological adaptation. Many of them go under the ground to live for the whole winter so as to escape the severe cold temperature of the winter season. This is just to survive in winter.

Intraspecific competetion in animal world

It is the law of nature that there is always the different types of competition  going in nature among the living organisms including the animals of nature. There are mainly three different types of competition going on in nature. They are :
-Intra specific competition
- Inter specific competetion and
- the competetion or the struggle going on against the forces of nature.
Intra specific competition or intrspecific struggle: It is the struggle or competition going on in nature between the animals of the same species. In this type of competition, there is the struggle going on mainly for the food, for space to live in and for the mating partner.
Inters pecific struggle or inter specificcompetition: This is the struggle going on in nature mainly for the food. This type of struggle takes place between a predator and the prey. In this type of competition one animal called predator usually kills the animal which is its prey. This type of competition takes place in the form of the predator and the prey relationship.
Struggle against the forces of nature:  The third type of competition goes on in such a way that all the animals are doing struggle to survive against the forces of nature which are not under the control. For example, flood, land slide, erosion, earthquake, storms like hurricane, tornado etc are the naturAL factors which occur unexpectedly and cause the destruction of large number of the living animals.
  Only a few animals are able to survive in the natural disaster and the large number of them die in the struggle.This phenomenon is known as the ''Struggle for existence''. Struggle for existence is the important part of Darwin's theory. It is the important element of Darwinism.

What is Anjina ?

Anjina is a symptom of the coronary artery disease. Progressive narrowing of the arteries, due to formation of plaque supplies inadequate oxygen rich blood to the heart muscles,during exercise or stress. This condition is called ''Ischaemia''. When 'ischaemia' of the heart muscles occurs, ''angina'' is  the pain signal from the heart asking for more rest.
Anjina Pectoralis? Anjina pectoralis means chest pain. This pain is often not identified to the chest. It is often a referred or radiating pain in the upper body, left arm, jaw or upper back. The pain can also show symptoms like heaviness in chest or indigestion. An anjinal attack normally lasts for less than five minutes. The effects of ischaemia on the heart muscle are reversible and do not result in the death of cells. An anjinal attack can be relieved by rest and medication.
How to diagnose anjina? Diagnosis of anjina can be made on the basis of one's medical history.The relation of one's symptoms to the physical activity or emotional stress, identify the risk of factors for atherosclerosis. Also, certain laboratory tests, a resting electrocardiogram and chest x-ray are needed to help make the diagnosis of one's disease.
Medical History  The pattern of discomfort or pain along with a review of one's medical history will help the doctor to make a provisional diagnosis of anjina.
- Th epriority is given to the nature of the discomport or pain. Its location , what brings it on and what it relieves - The risk factors will be identified by the doctor . Risk factors are overweight, smoker etc.
- The family history will be assessed .

How to find peace of mind?

Many people have good talent, health ,wealth and fame. But only a few have peace of mind.Its a question how can we get peace of mind?To get peace in mind , we should judge ourselves less harshly. We should not ascribe superior power to our neighbours. We should realise that all men and women bear the scars of many lost battles. Let us accept ourselves what we are i.e. a combination of strengths and weaknesses. We have to accept the truth that we are capable in some directions and limited in others. We have to remember also that we can and should change ourselves.
Every normal person can control fears and worries. Our feelings of insecurities are left over from childhood when we were below average. We should look at these shortcomings in the light of maturity and see that others are no less faulty than ourselves. As matured adults, we should withstand many shocks.
  The obstacles to peace of mind lie within us. If we free ourselves from 'shadow fears' , accept ourselves as we really are , learn to face grief  and remain beyond it , we can have peace of mind.

car

Cars are the vehicles with four wheels.They are used to transport mainly the passengers from one place to the other. The car has its  own engine for its operation. It has various numbers of seat usually for five to eight people.
         There are different types of car one of which is the motor car. It has the space for passengers along with the baggage. The use of cars have been found to connect the urban places to the suburban areas. The fuel used to operate the car engine is petrol, diesel and gasoline. The number of car is increasing annually in the industrial countries like India China Japan, U.S.A.etc.
          Cars are of different names like Ford car, Chevrolet car, Jeep, Hyundai, Honda, Mitsubishi, Toyota, Volkswagen, BMW etc. Cars are of different models. For example, Luxury cars, Sports cars, vans, Green cars etc.  

pisces

Introduction: Pisces are the animals which are included under phylum chordata. Their group is vertebrata. They have got jaws.So, they are also categorised under gnathostomata.

General characters of pisces:  Pisces exhibit the following characters:

-They aquatic in habitat. They live in any type of aquatic habitat like sea, lakes, ponds ditches rivers etc.
- They have stream - lined body shape which helps them to reduce water resistance during swimming mode of life.
-Locomotary organs are the fins which help in swimming. There are different types of fins in the body of fishes. Foe example, the dorsal fin, ventral fin, caudal fin, pectoral fin and pelvic fin.Among the different types of fins, the dorsal, ventral and the caudal fins  are unpaired and called the median fins where as the pectoral and pelvic fins are the paired fins. Fins are supported with finrays.
- Fishes respire through the gills. So, the respiratory organs are the gills which take in oxygen whch is dissolved in water. They give out carbondoxde.
- Their body is covered wth scales. Scales may be spiny or smooth and slippery. Some fishes have the spiny scales and some have the smooth and slippery scales.Anyway, Scales are the organs which protect the body of fishes from externsl injury and also help to hes escape from the enemies.
- Some fishes have the air-filled sac like  structures called air bladder. Air bladder helps them to live and adjust their body in the different depths of water accordng to their need.

Protochordates

Introduction: Protochordates can be defined as the primitive group from which chordate animals developed. Actually protochordates include all animals which were prior to the chordates.

Distinguishing characters of protochordates:  Following are t
he important characters of group Protochordata:
- They have a small rod like structure on the dorsal side of their body which is called notochord.
- They have the dorsal tubular nervous system whch is not very well- developed and is of primitive type.
- they have the primitive type of gill slits
Protochordate animals may have the notochord in the different places like in tail region or in head region and in one half region of the body.
Depending on the position of the notochord the group protochordata is again divided into following subphylum:
(1) Subphylum - hemichordata in which the notochord is present in the anterior one half of the body. The representative animal os this subphylum is called Balanoglossus.
(2) subphylum - urochordata in which the notochord is present in the tail region. The representative animal of this subphylum is called herdmania.
(3) Subphylum - cephalochordata. The representative animal of this phylum is called Amphioxus.
It is very important to know that all these three subphyla of the group protochordata although exhibit the primitive characters of phylum chordata can not be included under vertebrata because they do not have fdwell developed vertebral column. But they have the initial form of vertebral column which is just the notochord or the rod like structure found in the dorsal side of the body.

Survival of animals in nature

Introduction: It is very necessary and interesting to know that each and every living organism in the world are trying to survive or in the process of survival from the very beginning. Those animals which can survive best in the different types of changed environmental conditions can survive and adapt in nature. Such animals are considered to be successful animals of nature. On the other hand there are some animals which can not survive or adapt in the different types of the changed environmental conditions can no more survive in nature. For example Dinosaurs of the mesozoic era.
Why were dinosaurs wiped out in nature? Dinosaurs were the animals of mesozoic era in the history of earth. Formerly, they were dominating all the other animals of nature by their huge body which was more than a ton of body weight. But they had the less developed brain than the mammals. Suddenly the environment was changed in nature and all the herbivorous food source was destroyed.Dinosaurs which were dependent in the herbivorous food could not change the food habit from the herbivorous to the carnivorous type. Only those animals who could change their food habit survived in nature and the others which could not adjust their food habit from the herbivorous to carnivorous were destroyed in nature. This phenomena is known as the "survival of fittest."
What is natural selection? Natural selection is also one of the important phenomena in nature. It is one of the point of the theory of evolution of Charles Darwin which is popularly known as "Darwinism". According to the point "the natural selection", Nature helps those animals which help themselves. In other words, nature selects only those animals which are fittest in the survival process of nature. But those animals who could not change to adapt and survive in the different types of the changed environmental conditions are no more selected by natural in the list of new species.
Advantage of natural selection. the phenomena of natural selection is the important element of Darwin's theory which acts positively in the process of organic evolution or the gradual development of living organisms in nature.It gives strong evidence in favour of the fact that organic evolution has taken place in the earth and it is still an ongoing process.

Adaptation in aquatic vertebrate animals

Introduction: Adaptation is defined as the structural and physiological modification in the body of the living organisms in order to adjust themselves in the particular environment. Aquatic environment is the habitat which consists the large or smaller water bodies like sea,lakes, ponds, rivers ponds,streams and even the ditches and the pools.
Which animals are the aquatic vertebrates? Aquatic vertebrate animals are the vertebrate animals with back bone in their body and aquatic means living in any type of water body.Fishes, amphibians, reptiles, and mammals are the classes of which some of the animals of each group are adapted or adjusted to live in the aquatic habitat. Not all the animals of each group are adapted in water but only few of them are adapted to live in water bodies. For example, Fishes, amphibians, some reptiles, some birds and some mammals are adapted to live in water.
Adaptational features of the aquatic adapted animals : Animals which are adapted in aquatic habitat usually show the following  adaptational features:
- They have streamlined body shape which helps them to minimise water resistance which makes them to live easily in in water.
- Respiratory organs are gills or nostrils . But in perfectly adapted forms gills are the respiratory organs which help to take in dissolved oxygen from water and give out carbondioxide. Nostrils or the nose openings in the aquatic adapted vertebrates other than the fishes in which the position of nostrils is jfound at the or near the top of the head which makes them to take in oxygen from the air by frequently coming up to the surface of water.

- Locomotory organs are fins in the perfectly adapted forms like fishes but in other aquatic forms fins are not found but fin-like structures called flippers and paddle are found which help them to move easily in aquatic habitat.
- Modification  is also found in the toes in some aqsuatic animals. A thin fold of skin called web is developed between the toes for e.g. in ducks and frogs. Presence of helps them a lot to increase the surface area for swimming.
- Modification in the skin or under the skin is also found. For example, whales have the thick layer of fat under the surface of their skin which helps them in temperature regulation so that they can survive easily even in the extreme cold temperature of the winter season.

Some particulars about dogs, cats and pigs

Dogs are men's best friends: Dogs are the animals which are intelligent, good and use to show the basic obdience. They can learn to sit, lie down and fetch. They can even read their owner's intentions. They can at least find food in response to non-verbal cues,which is a type of understanding that scientists think may be akin to the human ability to understand some one else's point of view.
Cat's are adaptable: Cats are the carnivorous animals of phylum chordata of class mammalia. According to the report given by the cat owners ,they have trained their pet cats to sit down, roll over and jump through hoops. Cats learn the tricks by observation and imitation. But training cats is harder than dogs. But does that mean that they are less intelligent? Not necessarily. Cat experts say they are solitary animals which are motivated by the need to survive. This has allowed them to adapt a variety of domestic environment for at least 9,500 years.
Pigs: Pigs are also the chordates which belong to the class mammalia and the order primate. They are the smartest , cleanest domestic animals known more so than cats and dogs according to some experts..But pigs don't have sweat glands. So they roll around in the mud to stay cool.A sign of their cleverness came from  experiments. Pigs were trained  to move a curser on a video  screen with their snouts and used the curser to distinguish between scribbles they knew and those they were seeing for the first time. They learned the task as quickly as chimpanzees.

Lizards in the animal world

Introduction:Lizards are the vertebrate animals which have got a welll - developed vertebral column in their dorsal side of the body. They are more developed than fishes and amphibians but less developed then the aves and mammals.
Systematic position: Lizards are included under phylum chordata and class reptilia. Their order is lacertilia. There are two different orders in reptilia, one is lacertilia and another is ophidia. Lacertilia order includes lizards which are with two pairs of limbs. Order ophidia includes the snakes which are limbless lizard
Where do they live? They are terrestrial in habitat i.e. they live on dry terrestrial land. They are completely adapted to live  in dry terrestrial habitat. They have the stream - lined body with horney and dry skin. They have well-developed claws. They are also known as the first amniotic animals because of the presence of the amniotic cavity inside their body. Amniotic fluid present inside the amniotic cavity  helps them to float in the embryonic stage so  that they are not affected by dessication and drying and any dry condition of the environment.
How are lizards different from the snakes? Lizards are different from the snakes in habing two pairs of limbs, and hering capacity where as snakes are limbless and totally deaf reptiles without any ear.

STAR FISH, THE MACROINVERTEBRATE OF SEA

Introduction: Echinoderms are the latest group of macroinvertebrate animals which live exclusively in marine habitat. They are not found in any type of inland water. They have the spiny structures in the outer surface of their body or skin. So they are known as "echinoddermata". Several animals are included under this group like starfish, seacucumber, holothuria etc Among them starfish is very familiar to us. Actually starfish is not the fish. To be a fish the animal must be included under the phylum chordata in which all the animals having the vertebral column are included. But its very funny that starfish sontains neither the vertebral column nor it is a true fish. But still it is popularly known as "starfih." Zoology is a very funny subject although it is a biological study of animals. for example, naming of starfish is not based on any reasonable facts.
Why it is named starfish although its not actually a true fish? It is very interesting question to ask why starfish is named as is. Of course , all the fishes use to live in water. Starfish also lives in water like a fish. Its body is shaped like a star in the sky. So, there are two reasons behind the naming
of starfish. One is it lives in water all the time. And the another reason is that it has the shape like that of the star of sky. So, it is known as starfish.
What is  particular about starfish?  Starfish consists of certain characters which makes it special in the animal world. It consists of a unique system in its body which is not seen in any other groups of animals in the animal world. This is the special type of vascular system in which water circulates in its body. This system is known as "water vascular system". This system is scientifically known as ambulacral system. Another unique structure of its body is the presence of tub e like feet in the body which are called tube feet. They are the legs or locomotary organs of starfish which help in the movement.

MOLLUSCA, THE SHELLED INVERTEBRATES OF ANIMAL WORLD

 Introduction :Animal world consist of a particular group of animals which have their body covering made of of shell which is made up of calcium carbonate. Having been composed of calcium carbonate the shell is very hard in texture and give protection to the whole internal vital organs of the body.Inside the shell the various organs of the body are found in compact form concentrated in a mass  and this mass of all the internal visceral organs is known as "visceral mass". The body of these animals consists of the following parts which are anterior head, ventral muscular foot and visceral mass.

Why are they called the macroinvertebrates?: As the molloscs are the invertebrates with comparatively large sized body in comparison to all the other invertevrates from protozoa to arthropoda, they are called macro - invertebrates. Invertebrate animals with large sized body are a little bit different from micro invertebrates in the sense that they have more devveloped systems and structures in the body. Their digestive system, respiratory system,circulatory system,excretory system an reproductive systems  and  nervous systems are all well-developed  than the microinvertebrates.So they are considered to be one step forward in the developmental step according to the Naturalists.

Economic importance of macroinvertebrates including the animals of phylum mollusca: Molluscs and the other macro invertebrates are economically very important animals of nature. They use to live in aquatic and semiaquatic habitat. They always live in association with other animals and plants of nature along with the nonliving components like water, soil temperature, light and dissolved nutrients.
Molluscs help to filter the impure water and purify it. Molluscs use to eat the various dissolved and decayed vegetable materials of the inhabiting water turning the water clear and transparent. So, they are said to be helpful in water purification in the various types of inland waters like rivers, lakes, ponds, streams and pools.

Earth worms in the animal world

       Earthworms   Earthworms are the animals in the animal world which have the elongated cylindrical body with pointed anterior ends but blunt posterior ends. They have metamerically segmented body i.e. whole the body is segmented in such a way that external segmentation is continuous with the internal segmentation and each segment is true and complete. Such segments are annules or rings. Earthworms are also the invertebrate animals without any back bone i.e. vertebral column. These animals use to live in the moist places of the earth and have elongated worm like body, so they are known as earthrorms.
Earthworms as the friends of farmers: Earthworms are the animals which contribute a lot to the farmers in being the animals which help them to make the soil loose and perforated. They also discharge their wastes inside the soil. wastes discharged by earthworms is very rich in organic substances and large amount of humus i.e. the very fertile part of soil enriched with decayed vegetable materials. Moreover , such soil is also very rich in oxygen content. Nitrogen fixing bacteria prefer to live in such type of soil which help to increase the fertility of soil a lot by fixing nitrogen in the soil.
Earthworms as the laboratory animals: Earthworms are very popular as the laboratory animals. They are among the cheap animals and easy to collect from the land. They are supplied in the laboratory to be used for scientific experiments. They are very helpful to be used for experiments in scientific research.
Use of earthworms in medical treatment:  Earthworms are used as the animals whcih are use din the medical treatment of several types of diseases. For example, they are used in the treatment of jaundice, bladder disease, plague etc. Poder prepared by dried earthworms is very useful in the treatment of malnutrition.

Nematohelminthes in the animal world

Introduction: Nematohelminthes are the animals which have round and cylindrical body. They have the transparent white colour without any segmentation. They also lack cilia. Their body is elongated and pointed at both ends. Most of these animals are also live as the endoparasites inside the body of the other animals. As they have round and cylindrical body shape, they are popularly known as "round worms". They sexual dimorphism i.e. male and female reproductive organs are present in the differentt individuals. Nematohelminthes are also termed as aound worms schelminthes. Many animals of this group are familiar to us as the round worms. For example, hook worms, pinworms, filaria worms etc. Round worms are the very famous endoparasitic worms which are included under the phylum nematohelminthes.
Which part of the body they live in? Actually round worms use to live in the small intestine in the body of vetebrates especially in the children. Children are the main victim of round worms due to the lack of health awareness in them. They use to eat and drink with dirty hands without cleaning the hands with soap and water.
Disease they cause: Round worms enter inside the body of children especially with dirty habits along with the contaminated food and drinks and reproduce inside their body. They eat the digested nutrients of the alimentary canal of children and finally cause the disease called "ascariasis."

certain invertebrate animals of animal world

Invertebrate animals other than coelenterates are grouped under  the following phylum: Each mentioned phylum consists of the particular animals with particular characters as follows:

Phylum Platyhelminthes: This group of animal consists of the animals having dorsoventrally flattened leaf-like body. These animals are also known as flat worms. They are free-living as well as parasitic in habitat. But most of them are endoparsitic i.e. live inside the body of other animals and pass their whole life in this way. They are totally dependant on the other animals for food and oxygen. The animals which harbour them inside their body are called hosts.Animals which live inside the body of other animals are called endoparasites which are different from the ectoparasites which live out side the body and use to suck up the blood from the body of the other animals. Unlike ectoparasites ,endoparasites use to eat the digested food materials from the body of their hosts. Platyhelminth animals are very interesting being the one which show lots of modifications which enable them to live as the parasites. These animals have the hooks and suckers which are very helpful to help them   in the parasitic mode of life. Hooks help them to get attach firmly in the soft tissue of the hosts. Suckers help them to suck up the digested food materials from the body of their hosts. Other interesting facts about these animals is that they do not have the locomotary organs for movement. This is because they do not need these organs due to the fact that they get every essential things inside the body of the hosts.
Platyhelminthes or flat worms are hermaphrodite animals that means they have got both the male and the female reproductive organs in the same individual. Such animals are also known as bisexual or monocious..

Animals world

Introduction:  Animals world is actually the synoname of animal kingdom which includes the different types of animals present in nature. Animal world consists of the very large group in which only those  living things which show the distinguishing features of animals are included. They are different from other living groups which are included in plant kingdom. Basically, animals possesss the important characters which makes them to be animals and not the plants. Characters like capacity of movement, having the particular types of locomotary organs, power to grow continuously and gradually, property of showing irritablity i.e. showing response to the particular types of environmental stimulus like heat, cold,temperature,light touch, chemicals etc.  Although different from the plants in the different characters,animals also show the similarity with the plants as the plants are also the living things of nature. Similarity in   having the unit structure in their body called cell, being  able to respire, life's vital processes like metabolism, having the vital fluid called protoplasm in the cell, capacity to reproduce for the continuity of race are the the characters which make the animals similar to plants.: Animals world consists of animals which are of different types. They are differentiated into different types on the different ways and different basis. For example,
Invertebrates and vertebrates on the basis of presence or absence of vertebral column. Those animals which have aell-developed vertebral column in their body are said to be vertebrates. Those animals which have no vertebral column or backbone are said to be invertebrates. Animals are again diffrentiated into two groups on the basis of presence or absence of jaw. Those animals which have jaw are grouped into "Gnathostomata" and those animals which have no jays are grouped into "agnatha".  Animals are further classified into the different groups. some groups are larger and some are smaller. Very large group of animals is known as phylum , and the smaller group is called subphylum. Subphylum is further divided into classes and subclasses  which are further divided into order and suborders. Suborders are further divided into genus and genus into species. In this way it is very important to keep a particular animal in its part icular systematic position by keeping it in the order of its phylum,subphylum, class, subclass, order, suborder, genus and species. Keeping the animal in its systematic position or classifying the particular animal is the branch of biology which is called "taxonomy".
Classifification:   Animals are of various size and various types. Animals like invertebrates which have no vertebral column are classified into the following phyla i.e. the large group which are as follows:
Phylum1 Protozoa: This is the first invertebrate phylum which consists of the first appeared animals of animal world. These are unicellular or made up of only one cell, with the particular types of locomotary organelles and some of which may not hve such organelles. Animals like amoeba, paramecium, euglena, verticella, malaria parasites like plasmodium etc are included inthis phylum.
Phylum Porifera: This phylum includes the multicellular animals whcih living in aquatic habitat. They are more or less plant like with no locomotary organs. They remain fixed to the substratum.They are aquatic in habitat.
Phylum Coelenterata : This is the third invertebrate phylum which includes those animals which flattened body. Most of them live as parasites and live inside the body of the other animals called hosts.

animals world

Animals are the living organisms in the world which have certain characters which make them different from plants. They