A presentation for BSC biology semester 1 students. This rich presentation is about major phylum in animal kingdom, each phylum is explained in detail with their general characterstics. Can be used for presenting in college or school, teaching, learning, etc.

1. General Characteristics
of Major Phyla in the
Animal Kingdom
By Siddharth Sirvaiya
BSC CBZ sem1
Assignment - Zoology

2. Introduction
• Animals are eukaryotic, multicellular, species
belonging to the Kingdom Animalia. Every animal
has its own unique characteristics. They obtain
their energy either by feeding on plants or on other
animals. There are millions of species which have
been identified, few share similar characteristics
while others differ drastically.
• Another important feature is that they have a
heterotrophic mode of nutrition, which means that
they cannot make their own food.

3. Classification of Animals
classification is the process of arranging organisms, both living and extinct, into
groups based on similar characteristics. The science of naming and classifying
organisms is called taxonomy. The term is derived from the Greek taxis
(“arrangement”) and nomos (“law”).
The classification system commonly used today is based on the Linnean system
and has eight levels of taxa; from the most general to the most specific, these
are domain, kingdom, phylum (plural, phyla), class, order, family, genus (plural,
genera), and species. (For plants, the term division is generally used instead of
phylum.)

4. Kingdom Animalia
• Kingdom Animalia constitutes all animals.
Amongst the five kingdoms, the largest
kingdom is the animal kingdom. Animals
are multicellular eukaryotes. However, like
plants, they do not possess chlorophyll or a
cell wall. Therefore, members of the animal
kingdom exhibit a heterotrophic mode of
nutrition. Kingdom Animalia has been
classified into ten different subphyla based
on their body design or differentiation.
• The different phylum of the animal
kingdom are listed ahead.

5. Phylum Porifera
• This group of animals is probably
considered as the oldest animal group.
They are also called as Sponges. These are
by far the simplest multicellular animals.
Even though they are multicellular, they do
not have any tissues or organs. Sponges
live in an aquatic habitat as they have to
have an intimate contact with water. Water
plays a major role in the feeding, exchange
of gases and as well as excretion. The body
of the sponges has many holes or pores
called ostia. The body structure of sponges
is designed in such a way that water moves
through the body, where it can filter out
food and also absorb the dissolved oxygen,
along with eliminating waste material.

6. Characteristic Features of Phylum Porifera
They are generally marine aquatic
organisms, with a few freshwater
species.
Their bodies are asymmetrical.
Body shape can be cylindrical,
vase-like, rounded or sac-like.
They are diploblastic animals with
two layers, the outer dermal layer
and the inner gastral layer. There
is a gelatinous, non-cellular
mesoglea, in between these two
layers. This contains many free
amoeboid cells.
The body has many pores called
the ostia and a single large
opening called osculum at the
top.
Spongocoel is the body cavity that
is present.
They have the characteristic canal
system for the flow of water
through the body.
Sense organs are absent.
There is an endoskeleton present
with calcareous spicules (calcium
carbonate) or siliceous spicules
(silica) or sponging fibres
(protein).
Sexes are not separate.
Asexual reproduction is seen
through budding, fragmentation.
Sexual reproduction is seen in
certain species, through gametic
fusion.

7. Glass Sponge
Calcareous sponge Demosponge
Some
examples of
organisms in
phylum
porifera

8. Phylum Cnidaria
• These are typically invertebrate animals,
which show a very simple level tissue
organisation. They are aquatic animals
and are mostly found in marine
environments, attached to the rocks at
the bottom of the ocean. A few species
are also found in freshwater habitats.
Coelenterates can be found solitarily or
in colonies. You can find them sedentary
or free swimming.
• Coelenterates can be called as the
simplest animal group that has true
tissues and have the characteristic
coelenteron or the gastrovascular cavity.

9. Characteristic Features of Phylum Coelenterata
They are multicellular
organisms, exhibiting
tissue grade of the
organisation.
They are diploblastic, with two layers
of cells, an outer layer called the
ectoderm and the inner layer called
the endoderm. There is a non-cellular
layer that is the mesoglea in between
the ectoderm and the endoderm.
They show
radial
symmetry.
They have a single
opening in the body
through which food is
taken in and also
waste is expelled out.
The opening in
the body is
surrounded by
tentacles.
Digestion takes
place in the body
cavity which is the
coelenteron.
They can live in
marine or
freshwater
habitats.
They can be solitary
or live in colonies.
Each individual is a
zooid.
These organisms
show two
morphological
forms – Polyps and
Medusa.
Polyps contain
exoskeleton and
endoskeleton.
The skeletons
are composed of
calcium
carbonate.
Most if the coelenterates are
carnivorous in nature with a
few exceptions such as the s
corals. They get their food
from other animals that live
symbiotically within them.
Digestion is both
intracellular and
extracellular.
Tentacles have special structures
known as the nematocysts which help
in capturing and paralyzing prey.
Coelenterates simply wave their
tentacles and when a prey comes in
contact, the nematocysts inject the
toxin that paralyses or kills the prey.
Nematocysts are the most
distinguishing feature of this phylum.
Coelenterates
do not have
sensory organs.
respiration and
excretion occur
through simple
diffusion.
The circulatory
system is
absent.
Asexual reproduction is
seen in polyps, through
budding and sexual
reproduction is seen in
medusa form, through
gametic

10. Box jellyfish Sea anemone
Immortal Jellyfish
Some
examples of
organisms in
phylum
cnidaria

11. Phylum
Platyhelminthes
• Platyhelminthes are commonly known as
flatworms or tapeworms. They are a
group of soft-bodied invertebrate
animals. As a matter of fact, there are
around 20,000 species of these animals.
A few of these live as parasites on
humans and other animals.
Furthermore, it is because of this
parasitic nature that they do cause some
amount of trouble for the host animal. A
few species belonging to this phylum can
be a major cause of certain diseases. For
example, Schistosomiasis, or bilharzia or
bilharziasis, is a disease caused by these
parasitic flatworms. They belong to the
family Schistosomatidae.

12. Characteristic features of Phylum Platyhelminthes
Their body is
dorsoventrally
flattened.
They exhibit
bilateral
symmetry.
Also, they are
triploblastic, with
three germ layers.
They do not have a
body cavity and are
acoelomate.
The body is soft
and
unsegmented.
They are mostly
parasitic with a few
free-living
They exhibit an
organ system grade
of organization.
The digestive system is incomplete or
absent. In fact, there is a single
opening which leads to a well-
developed gastro-vascular cavity.
Also, the anus is absent. And there is
no true stomach structure. In a few
species, the digestive system is
completely absent.
Respiratory and circulatory
systems are absent. In fact,
the respiration generally
occurs by simple diffusion
through the body surface.
The flame cells help in
excretion. The
excretory system has
protonephridia with
the flame.
These animals are
hermaphrodites i.e. both
male and female organs
are present in the same
body
Sexual reproduction
happens through
gametic fusion.
Asexual reproduction also
happens in a few species
through regeneration and
fission.
Fertilization is
internal.
The life cycle of these
organisms can be complex,
especially if they are
parasitic, as this may involve
one or more host animals.

13. Tapeworms
Turbellaria
Rhabditophora
Some examples of organisms in phylum Platyhelminthes

14. Phylum
Nematoda
• Aschelminths can be free-living
or parasitic. The free-living
organisms are extremely
abundant in soils and sediments
and they feed on bacteria. While
some others are plant parasites
and can cause disease in crops
that are economically important.
The others are parasites that can
be found in animals and human
beings. Some of the parasitic
worms include hookworms,
pinworms, Guinea worms, and
intestinal roundworms.

15. Characteristic features of Phylum Aschelminthes
The body of these
organisms is
unsegmented and
triploblastic.
They have a
pseudocoeloem, where
the body cavity is not
lined by the
mesodermal layer.
They are bilaterally
symmetric.
The body is cylindrical or
thread like with elongated,
slender worm-like
appearance and tapering at
both ends.
Body wall has
epidermis, muscle
layer and is covered
by cuticle.
The body size of these
organisms varies from
microscopic to several
centimetres in length.
These organisms
are mostly
parasitic, with a
few free-living
They exhibit an
organ system level
of organization.
Externally, there is little
differentiation between the
anterior and posterior
regions. But internal
cephalization is present.
There is no distinct head.
However, the mouth is
present in the anterior
The digestive system
is complete, with a
mouth and anus.
The mouth in these
organisms is terminal and is
surrounded by lips bearing
sense organ.
Amphids and papillae
are the main sensory
organs.
The nervous system consists
of a nerve-ring that
encircles the oesophagus.
From it, nerves extend out
anteriorly and posteriorly.
Respiratory organs are
absent. Respiration occurs
through the general body
surface. It is aerobic in free-
living forms and anaerobic
in parasitic organisms.
The excretory
system has canals
and gland-like
Sexes are separate and are
unisexual, exhibiting sexual
dimorphism.
Fertilization
is internal.
They are ovo-
viviparous, oviparous
or viviparous.
The life cycle of these
organisms is complicated. It
may be with or without an
intermediate host.

16. Root-knot nematode Caenorhabditis elegans
Ascaris lumbricoides
Some
examples of
organisms in
phylum
nematoda

17. Phylum Annelida
• Having over 17,000 species, Phylum
Annelida is a large phylum. Annelids are
also known as ringworms or segmented
worms. They exist in various
environments including marine waters,
fresh waters and also in moist terrestrial
areas. The size of the annelids can range
from a few millimeters to an amazing
three meter in length. The Australian
earthworm measures around 3 meters.
Furthermore, some species from this
phylum exhibit some unique shapes and
brilliant colours.

18. Characteristics of Phylum Annelida
They have a long and
segmented body.
Annelids are bilaterally
symmetrical.
They are triploblastic.
Also, they exhibit
organ system grade of
organisation, showing
organ differentiation.
The body is covered
with a thin cuticle.
They are coelomate. A
body cavity or coelom
is present.
Annelids live in moist
environments, moist
soil, freshwater and
marine water.
They have parapodia
and chitinous setae,
used for locomotion.
Their body appears
red due to the
presence of
haemoglobin.
Excretory and nervous
systems are present.
The digestive system is
complete and
developed.
Respiration happens
through the general
body surface.
These invertebrates
have a true closed
circulatory system.
Sexes may be separate
or united, wherein
they are called
hermaphrodites.
Fertilization can be
internal or external.

19. Bobbit worm
Leech
Earthworm
Some
examples
of
organisms
in phylum
Annelida

20. Phylum
Arthropoda
• Arthropods are joint-legged animals and
you must have come across a few of
these animals. Some prominent ones
include insects, spiders, ants, bees,
crabs, shrimps, millipedes, centipedes
etc. Scientifically speaking, they all come
under the Animal Kingdom under
phylum Arthropoda.
• The success of the arthropods can
mainly be attributed to the presence of
exoskeleton, which makes them
versatile, is protective in nature and also
allows flexibility and mobility. You can
see arthropods living on land and in
water. They are also a source of food for
many animals and human beings too!

21. Characteristic features of Phylum Arthropoda
The body structure shows
bilateral symmetry.
They are triploblastic.
They can be found in all
types of habitats – land,
water and soil.
They have jointed limbs.
The body is segmented into
three regions – Head,
Thorax and Abdomen.
The body cavity is filled
with blood and is called the
haemocoel. The blood is
white in colour.
The exoskeleton is
hardened and is made of
chitin.
They have a well-
developed central nervous
system.
The head is well developed
and bears the sensory
organs and brain.
They have compound eyes
and mosaic vision.
The digestive tract is
complete with the mouth
and anus at opposite ends
of the body.
They have an open
circulatory system with
dorsal heart and arteries.
Respiration is through the
general body surface or by
gills in aquatic forms and
through trachea or book
lungs in terrestrial forms.
Sexes are separate and
sexual dimorphism is
exhibited.

22. Scorpion
Crustacean Bees
Some
examples of
organisms in
phylum
arthopoda

23. Phylum Mollusca
• Many organisms belonging to this
phylum have a calciferous shell.
The bodies are generally very soft
and are covered by the hard
exoskeleton. They can be found in
terrestrial regions as well as in the
depths of the seas. You will be
amazed to know that the size of
the molluscans can range from 20
metres to one millimetre, with a
few microscopic animals too.
These animals continue to have
an important role in the lives of
humans.

24. Characteristic Features of Phylum Mollusca
They are
bilaterally
symmetrical.
They are
triploblastic,
which three layers.
They show organ
system grade of
organisation.
The body is
soft and
unsegmented.
Body is divisible into
three regions – head, a
visceral mass, and
ventral foot.
Body is covered by
a mantle and shell.
They can be found in
different habitats,
both aquatic and
terrestrial.
The body cavity is a
haemocoel, through
which blood
circulates.
The digestive system is well
developed and complex. It
has a radula, which is a
rasping structure that has
chitinous teeth. It is used in
feeding.
The nervous system
is made up of paired
ganglia, connectives,
and nerves.
The circulatory
system is open,
with heart and
aorta.
Respiration occurs
through gills called
ctenidia.
The ventral
muscular foot
helps in
locomotion.
They have a pair
of kidneys
(metanephridia)
Sexes are separate
and reproduction is
through sexual
reproduction.
Fertilisation
can be internal
or external.

25. Cephalopod
Gastropods Cuttlefish
Some
examples of
organisms in
phylum
mollusca

26. Phylum
Echinodermata
• Echinodermata may look
morphologically (structure and form)
dissimilar at a glance, but they all share
the same characteristic features. These
animals have some really unique shapes
and have beautiful colours. They are
important ecologically and geologically,
as they provide valuable clues about the
geological environment.
• Did you know that they can regenerate
limbs? When a starfish, with five arms,
losses one arm, it has the capacity to
regenerate the lost arm. This
regeneration can take any time between
several months to years, as the wound
has to heal and then only are the new
cells regenerated.

27. Characteristic Features of Phylum Echinodermata
These are
exclusively marine
animals.
The larval forms
show bilateral
symmetry and adult
forms show radial
symmetry.
They are
triploblastic.
It exhibits organ
system grade of
organisation.
They have a
true coelom.
The body is uniquely
shaped. It can star
like, elongated or
spherical.
The body is
unsegmented
without a head.
The body surface
is covered with
calcareous
spicules.
Body cavity has
the distinguishing
water vascular
system.
Tube feet help
in locomotion.
The brain is absent but
a nervous system is
present with a nerve
ring and radial nerve
cords.
Respiration occurs
through tube feet
and gills.
Sense organs are poorly
developed and include
tactile organs,
chemoreceptors,
terminal tentacles etc.
Sexes are
separate.
Fertilisation
is external.
Lost parts can
be
regenerated.

28. Sea cucumber
Brittle stars Sea urchins
Some
examples of
organisms in
phylum
Echinodermata

29. Phylum
Chordata
• This phylum is probably the most
notable phylum, as all human beings and
other animals and birds that are known
to you, fall under this phylum. The most
distinguishing character that all animals
belonging to this phylum have is the
presence of notochord.
• It will surprise you but this phylum is a
very diverse phylum, with about 43,000
species. Most of these organisms can be
found in the subphylum Vertebrata. In
the animal kingdom, this is considered as
the third largest phylum.

30. Characteristic Features of Phylum Chordata
They are bilaterally
symmetrical and
triploblastic.
Chordates are coelomate
and show an organ system
level of organisation.
They have the characteristic
notochord, dorsal nerve
cord, pharyngeal slits.
Also, they have a post-anal
In this phylum, the nervous
system is dorsal, hollow and
single.
The heart is ventral, with a
closed circulatory system.
The habitat of these animals
is widespread. So we can
find them in the marine
environment, fresh waters as
well as terrestrial
environments.

31. Some examples
of organisms in
phylum
chordate

32. Conclusion
the animal kingdom stands as a
testament to the incredible diversity
that exists within the natural world.
From the foundational simplicity of
organisms in Phylum Porifera to the
sophisticated complexity observed in
Chordates, the spectrum of life within
this kingdom is vast and awe-
inspiring. The vast array of body plans,
modes of reproduction, and
ecological adaptations showcase the
remarkable adaptability and resilience
of life on Earth.

33. References
Wiki pedia
Google images for images
Britannica
Lumen learning