Kingdom Animalia Characteristics
General characteristics of the Kingdom Animalia are as follows:
Animals are eukaryotic, multicellular and heterotrophic organisms.
They have multiple cells with mitochondria and they depend on other organisms for food.
Habitat - Most of the animals inhabit seas, fewer are seen in fresh water and even fewer on land.
There are around 9 to 10 million animal species that inhabit the earth. Only 800,000 species are identified.
Biologists recognize 36 phyla in the animals kingdom.
Size - The sizes of animals ranges from a few celled organism like the mesozoans to animals weighing many tons
like the blue whale.
Animal bodies - Bodies of animals are made of cells organized into tissues which perform specific functions. in
most animals tissue are organized into complex organs, which form organ systems.
Cell structure - The animal cell contains organelles like the nucleus, mitochondria, Golgi complex, ribosomes,
endoplasmic reticulum, lysosomes, vacuoles, centrioles, cytoskeleton.
Animals are made up of many organ systems, that aids in performing specific functions that are necessary for
the survival of the organism.
Organ systems are skeletal system, muscular system, digestive system, respiratory system, circulatory system,
excretory system, reproductive system, immune system and the endocrine system.
Body symmetry - Most of the animals are bilaterally symmetrical, while primitive animals are asymmetrical and
cnidarians and echinoderms are radially symmetrical.
Locomotion - Most animals have the ability to move, they show rapid movement when compared to plants and
other organisms.
Respiration - It is a gaseous exchange of taking in oxygen and giving out carbon dioxide. This process takes place
in organs of respiration like the lungs, gills, book gills and book lungs and some animals skin is also used for
respiration.
Digestion - Animals ingest food, and digestion takes place in the internal cavity like the digestive system in
animals, in primitive animals vacuoles are for digestion.
Nervous system - Sensory mechanism and the coordination of the organ systems is carried on by the nervous
system. In animals the nervous system comprises of nerve ganglions, or brain, spinal cords and nerves.
Circulatory system - The distribution of nutrients, exchange of gases and removal of wastes takes place in the
circulatory system. This system comprises of the heart, blood vessels and the blood.
Excretory system - Removal of wastes from kidneys.
Skeletal system - support and protection is provided by the skeletal system.
Reproductive system - Most animals reproduce sexually, by the fusion of haploid cells like the eggs and the
sperms.
Glands of the endocrine system help in control and coordination of the body system.
Kingdom Animalia Classification
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Kingdom Animalia has approximately 36 sub-divisions known as 'phyla'. Each phyla share particular properties structurally
and functionally which together separate it from other phyla. Below are the most common phyla classified under traditional
biological methodology.
Phylum Porifera - They are primitive organisms, most of them are salt-water sponges. They do not have organs or nerve
cells or muscle cells. Approximately, 8,000 species exist today. Example: Sycon, Euspongia, Spongilla.
Phylum Coelentrata (Cnidaria) - This group is composed of jelly-fish and other lower aquatic animals. Approximately,
15,000 species exist today.Example: Aurelia, Adamsia.
Phylum Platyhelminthes - This group consists of flat worms. They inhabit both marine and fresh water habitats and they
are mostly endoparasites found in animals. Example: Taenia, Fascicola.
Phylum Aschelmeinthes - It is a group of round worms, most of them are parasites. This phylum consists of about 80,000
parasitic worms.
Phylum Annelida - They are present in aquatic, terrestrial and are free-living or parasitic in nature. This phylum comprises
of segmented worms. Example: Earthworm, Leech etc.
Phylum Arthropoda - This is the largest phylum which consists of insects. There are over 1 million species of insects
existing today. Example: Locusts, Butterfly, Scorpion, Prawn.
Phylum Mollusca - It is the second largest phylum. They are terrestrial and aquatic. Example: Pila, Octopus.
Phylum Echinodermata - This consists of sea stars and sea urchins. There are about 6,000 species.
Example: Asteria, Ophiura.
Phylum Chordata - Animals of this phylum have a characteristic feature of presence of notochord, a dorsal hollow nerve
cord and paired pharyngeal gill slits. Within this phylum advanced group called vertebrates which include fish,
amphibians, reptiles, birds and mammals.
Kingdom Animalia Examples
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Some of the well known examples of Kingdom Animalia
Phylum Porifera - Sycon, Euspongia, Spongilla.
Phylum Coelentrata - Aurelia, Adamsia.
Phylum Platyhelminthes - Taenia (Tapeworm), Fascicola (Liver fluke).
Phylum Aschelminthes - Ascaris (Round worm), Wuchereria (Filaria worm), Ancylostoma (hook worm).
Phylum Annelida - Nereis, Pheretima (earthworm), Hirudinaria (blood sucking leech).
Phylum Arthropoda - Apis (honey bee), Bombyx (Silkworm), Laccifer (lac
insect), Anopheles, Culex and Aedes (mosquiotes), Locusta (locust), Limulus (king crab).
Phylum Mollusca - Pila (Apple snail), Octopus (devil fish), Pinctada (pearl oyster), Aplysia (sea-hare), Sepia (cuttle-
fish), Dentalium (Tusk Shell), Chaetopleura (Chiton).
Phylum Echinodermata - Ascarias (star fish), Echinus (sea urchin), Antedon (Sea lily), Cucumaria (sea
cucumber), Ophiura (brittle star).
Phylum Chordata - Balanoglossus, Ascidia. All fishes, amphibians, reptiles, birds and mammals.
