Animal Categories
Amphibians   .   Annelids  .   Arachnids  .   Birds   .    Cnidaria      Crustaceans   Echinoderms     Fish    .    Insects        Mammals       Marsupials   .      Molluscs   .    Reptiles   
INVERTEBRATES 
Animals without a backbone

Invertebrates do not have an external skeleton made of bone. Others have a hard outer shell.  The most common invertebrates include:  

Annelids *  Anthropods *  Echinoderms  *  Mollusks   Protozoa   

Many invertebrates have a fluid-filled skeleton (jellyfish and worms), whilst others have hard outer shells.  (insects and crustaceans).  

More than 98% of the animal species in the world are invertebrates.  
VERTEBRATES 
Animals with a backbone

Invertebrates have an internal skeleton made of bone.   Vertebrates include:


Amphibians  *  Fish  *  Reptiles  *  Birds  *   Mammals
Primates   *  Rodents  *   Marsupials

Most large land animals are vertebrates - even large sea animals.  Although vertebrates represent only a small percentage of all animals, their size and mobility allow them to dominate their environment.
Sleeping through the winter is called HIBERNATION
Sleeping through hot and dry periods is called ESTIVATION
WARM BLOODED ANIMALS
Almost all mammals and birds are warm-blooded.  They try to keep the inside of their bodies at a constant temperature.  They do this by generating their own heat when they are in cooler environments, and by cooling themselves when they are in hotter environments.  
Warm- blooded animals require much more food to survive.  
COLD BLOODED ANIMALS
Almost all insects, amphibians and arachnids are cold-blooded. These creatures take on the temperature of their surroundings.  When the environment is hot, they are hot and vice-versa.
​They are also much more active in warm environments and very sluggish in cold environments.  
EXCEPTIONS TO THE RULE are bats and mole rats.  Certain insects - such as hawk moths and some bees can raise their body temperatures by beating their wings.  Some fish have internal mechanisms to help keep their brains and eyes from becoming too cold.  
Visit:
​http://www.wisegeek.com/what-is-the-difference-between-warm-blooded-and-cold-blooded-animals.htm
ANNELIDS
Annelids are invertebrates consisting of over 17,000 species of worms - earthworms and leeches.  They live in damp, moist and wet soils as well as marine and freshwater environments. Many annelids move using muscle contractions and expansions to sweep along the body - like a wave.  They can crawl and swim.  Other annelids move by using a whip-like movement of the body. 
*   Earthworms   *   Ragworms   *    Leeches   
ARACHNIDS
Arachnids are invertebrates with eight legs.  However, in some cases, the front pair of legs have become adapted for feeding, defines, sensory perceptions and are not used for walking.  Almost all arachnids live on land, although some live in freshwater areas.  Arachnids differ from insects because they have eight legs (not six) and they don't have antenna or wings.
*   Spiders   *   Scorpions   *   Harvestmen   *   Ticks   *   Mites
BIRDS
Birds are vertebrate, winged animals with two legs and lay eggs.  They are also feathered with a beak (no teeth).  Birds are warm-blooded (they are able to control their body temperature by internally regulating their metabolic rate).  Although all birds have wings, not all of them can fly - for example: the penguin and the ostrich.  Many migrate to take advantage of seasonal temperatures, food sources and breeding habitats.  Some birds live in small family groups (Eagle and Hawks) and others in large flocks to provide them with safety.  
*   Birds
CNIDARIA
Cnidaria are invertebrates found in aquatic and marine environments.  Cnidaria comes from the Greek work 'cnidos' meaning stinging nettle.  Some Cnidaria are free-floating (Jellyfish), whilst others are stationery (sea anemone) and both have tentacles and can sting ... and in the case of the sea wasp, the sting can be deadly.  
*   Jellyfish   *   Sea Anemone   *   Coral   *  Sea Wasp
CRUSTACEANS
Crustaceans are invertebrates.  They are also part of the anthropod family (meaning that they have jointed feet).  Most crustaceans live in water and they have a hard outer shell to protect the body.  Their legs are used for crawling and swimming and many have claws.
*   Crabs   *   Lobsters   *    Crayfish   *   Shrimp   *   Barnacles   *    Krill
ECHINODERMS
Echinoderms are a type of invertebrate found in marine and ocean environments.  Most echinoderms have arms or spines that radiate from the centre of the body.  
*   Sea Star   *   Sea Urchin   *   Sand Dollar   *   Sea Cucumber
FISH
Fish are vertebrates and live in water from which they breathe oxygen through gills.  Fins are also a common characteristic of fish, although not all fish have fins.  The fins are use to propel them through the water and their bodies are covered in scales.
INSECTS
Insects are invertebrates and are also a type of anthropod.  Insects are one of the largest classes of animals and can be found anywhere on earth.  Their bodies are in three parts - head, thorax and abdomen.  The head includes the brain, two compound eyes, mouth parts and two antennae.  The thorax has thee pairs of jointed legs and on some, one or two pairs of wings.  The abdomen consists of the digestive, respiratory, excretory and reproductive organs.
MAMMALS
Mammals are vertebrate animals.  Mammals are warm-blooded, air-breathing animals with hair or fur on the body.  The term mammal comes from the fact that female mammals have mammary glands that produce milk to feed their young. 

There are three types of mammals - placentals, marsupials and monotremes). Most mammals give birth to live young (placentals) ... others have a pouch in which females carry their young through early infancy (marsupials) and others, such as the platypus, are unusual mammals that lay eggs to give birth to their young.

There are approximately 5,500 specials of mammals divided into 153 families of animals.  
*   The largest family are rodents:  mice, rates, porcupines, beavers and other gnawing animals
*   The next largest family are the chiroptera or bat family
*   The next is the soricomorpha family:  shrews and moles

Followed closely by:
*   The carnivore family:  dogs, cats, bears and weasels
*   The cetartiodactyla (hoofed animals):  cows, deers, pigs and hippopotamus
*   The primates:  humans monkeys and apes

Mammals are the only animals with flaps around the ears.  This does include whales and dolphins, although the flap is concealed inside.  Most mammals have a good sense of sight, smell and hearing

The largest mammal is the Blue Whale and the smallest is the tiny hog-nosed bat (a fully grown adult weighs less than a teaspoon of rice (2 grams in weight).  

MARSUPIALS
Marsupials are unique mammals in that the female has a pouch in which to carry and nurse her young.  When the newborn is born, it crawls into the pouch and latches onto the mother's nipples and will remain in the pouch through early infancy.  
*   Kangaroo    *   Koala   *   Wallaby   *   Wombat   *   Tasmanian Devil   *   Bandicoot   *   Opossum
MOLLUSCS
Molluscs are invertebrates that live in the ocean, freshwater and terrestrial habitats.  There are several different classes, the most common of which are gastropods (snails and slugs) - the cehalopods (octopus, squid and cuttlefish) and the bivalves (clam, muscle, oyster and scallop).  The Giant Squid and the Colossal Squid are the largest animals without a backbone.
*   Snails    *   Slugs    *   Octopus    *    Squid    *    Cuttlefish    *   Clam    *    Muscle    *    Oyster    *    Scallop
REPTILES
Reptiles are some of the oldest life forms found on Earth.  They are cold-blooded, four-legged vertebrates and the skin is covered with a tough external plate - such as the shell of a turtle or the scales on a crocodile. Whilst
most reptiles spend a considerable amount of time in water, all reptiles breathe using lungs.  Reptiles lay eggs with a tough, leathery shell.

There are four classes of reptiles:
*   Crocodilia:             crocodiles, caimans and alligators
*   Squamata:            lizards and snakes
*   Testudines:           turtles and tortoises
*  Sphenodontia:      tuataras - a reptile endemic to New Zealand
​  
('Tuatara' derives from the Maori language and means 'peaks on the back').  This reptile is protected by New Zealand law - since 1895 and are threatened by habitat loss and introduction of predators such as the Polynesian Rat. 
                          
Acknowledgements:         Animal Kingdom - All about the World of Animals : 
                                     http://www.animalkingdom.net
                                  
                                     The Kiwi Conservation Club: 
                                     http://www.kcc.org.nz/tuatara