Classical Zoology : Invertebrates _Chapter 03 Follow us on …
Dear friends welcome in Ramonika classes
today we will study
3rd chapter of classical zoology Invertebrates video series
in which we will study the outline of classification
Scientists have proposed many classsification
systems to classify invertebrates
In which most popular and accepted classification
is the classification of Storer and Usinger.
They have classified the whole animal Kingdom in
23 phyla. They divided the animal kingdom
into two sub kingdoms
on the basis of the cell numbers.
Protozoa and Metazoa.
In Protozoa, All unicellular or
acellular animals are included and protozoa
phylum is placed in this sub kingdom
All multicellular animals are placed
into Metazoa sub kingdom.
Metazoans, further on the basis of
grade of body organization are divided in
three infra kingdom.
Mesozoa, Parazoa and Enterozoa.
In Mesozoa, grade of body organization
is type of cellular grade.
some digestive cells are present and all are
In which, Mesozoa phylum
is included.
In Parazoa, grade of body organization is types of
cellular and tissue level. In which,
Digestive cells are more than mesozoa.
Porifera phylum is placed in this infra kingdom.
In Enterozoa, grade of body organization
is type of tissue and organ system
level. On the basis of symmetry and germ layer,
Enterozoa were divided into two grades.
Radiata and Bilateria.
In Radiata,
Radial or biradial symmetry present.
They are diploblastic animals
means mesoderm
is absent in these animals. Epidermis as a ectoderm and
Gastrodermis as a endoderm
In place of mesoderm, they have
mesoglea layer.
In Radiata, two phylum are included.
First is Coelenterata or Cnidaria in which
Radial symmetry and
Cnidoblasts cells present.
Second phylum is ctenophora of radiata grade.
Animals of ctenophora show biradial symmetry and
contain comb plates. let's talk about
Bilateria Grade. In bilateria
Bilateral symmetry
present and they are triploblastic animals.
on the basis of origin of mouth
are divided into two divisions.
Protostomia and deuterostomia
Animals in which, mouth is formed
from blastopore
(कोरक रंध्र ), are placed in Protostomia.
Animals in which Anus is formed from
blastopore instead of mouth, are
placed in deuterostomia.
Both Protostomia and Deuterostomia,
on the basis of types of coelom,
are divided into sections or sub divisions.
Protostomia is classified into Acoelomata,
Pseudocoelomata and Coelomata.
same, Deuterostomia is classified into
In Acoelomata, animals in which
coelom is absent, are placed.
Mesodermal cells,
between ectoderm and endoderm
are present as a solid mass of
In which, Platyhelminthes,
Rhynchocoela or
Nemertinea are placed.
In Pseudocoelomata, coelom
present but
only outer side of its, covered with
mesodermal tissue. So
Both sides (outer and inner) of coelom are not
covered by mesoderm. only outer line of
body cavity or coelom contains mesodermal tissue or layer.
In this section, Phylum Aschelminthes,
Entoprocta and acanthocephala are included.
Lets talk about Coelomates animals of
Coelom is completely covered by mesoderm
and coelom is formed by splitting of
in these protostomia animals,
Phylum Annelida, Mollusca and Arthropoda
are placed.
we talk about
animals of Deuterostomia.
In these animals, coelom
is true and it
covered by mesoderm on both sides.
Here, the formation of coelom,
is completed by coelomic pouches that is
formed from Archenteron.
On this point, one more thing also noticeable
the coelom
In protostomia
is schizocoelous type
and in Deuterostomia, coelom is
Enterocoelous type.
we can see here that
Annelida, arthropoda and Mollusca are schizocoelous.
Echinodermata, Hemichordata and Chordata are
Now talk about some other phyla
that are minor phyla.
these minor phyla are also included in
Coelomata section. example
Sipunculida, Phoronida,
Echiurida, Ectoprocta,
are minor phyla which are included in
coelomata. lets talk about,
Nowdays, which phyla are grouped
or read by us
as a major phyla.
Total 09 phyla are grouped as major
phyla in invertebrates.
Invertebrates are classified into 09 phyla.
Protozoa, Porifera, Cnidaria
Platyhelminthes, Nematoda,
Annelida, Arthropoda, Mollusca
Echinodermata. Here, one more thing
is important for us
that we now talk about Aschelminthes,
In present, Aschelmithes is considered as a
super phylum and it consists of
five phylum that are
Rotifera, Gastrotricha,
Kinorhyncha, Nematoda and
Nematoda considered as
a major
Now come on Hemichordata,
are placed in chordata
as a sub phylum along with
two other sub phyla
Urochordata and Cephalochordata'
the concept of Minor and Major phyla
is based on two factors:
(i) Number of species
and Individuals.
(what numbers of species and what numbers of individuals)
and second,
(II) their participation
in ecological communities.
or how much they contribute their role in ecosystem.
On these factors, we classify all animals
into major and minor phyla.
We saw here,
in the section of coelomata.
In coelomata,
coelom is of two types:(i) Schizocoelous
(ii) Enterocoelous.
Echinodermata, Hemichordata and Chordata
are enterocoelous animals and
Annelida, Arthropoda, and Mollusca are schizocoelous animals.
So, this is
outline of classification that we studied here.
In the previous chapter, we learned the
basis of classification.
and before this chapter, we also read the classification
of whole living organism.
if you shall learn this chapter,
basics of Invertebrates and
vertebrates are cleared.
then when we will start next video or chapter of
this video series, then we will take
first phylum protozoa,
in which we will learn the characters of protozoa and then its classification.
So to learn or study these further chapter, we should have knowledge of basics.
As more as we will learn, our basics of
invertebrates will also increase.
We will perform better in competitive exams and
In exams of UG and PG courses,
We will obtain good marks.
So requested to all,
all video series
must be carefully watched. See all the video completely and
also learned from these videos. The contents that are
provided in both Hindi and English language,
important for Hindi medium students.
It is a tonic for Hindi medium students.
Because these problems also faced by me.
Students from rural areas are faced
these problems when they encountered with English in higher studies.
Because most of the books of science are published in the English language.
So they always faced difficulty to read these books.
to take in mind these problems of hindi medium students,
I prepared notes in both Hindi and English language.
I worked hard on these notes and
It will be very useful for all of you.
So more and more students watch this video.
So share and subscribe to this channel
and with this, the lesson is complete.
thanx to watching.

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