){kind=link}
Read more
Classification of invertebrate zoology
Invertebrates are classified into the
following 8 phyla such as;
|
1.
Phylum protozoa 2. Phylum porifera 3. Phylum coelenterate 4. Phylum Platyhelminthes 5. Phylum Annileda 6. Phylum Mollusca 7. Phylum Arthropoda 8. Phylum Echinodermata |
Phylum Protoza
The name protozoa (Gr. Protos-first, Zoon-anima) comes from
Goldfuss in (1818). The number and variety of protozoa is very great, about
more than fifty thousand species of protozoa are present over all the world.
Although over 20,000 of them are fossils forms.
Genernal Character of Protoza;
Protozoa are generally microscopic and acellular animals. Protozoa may be free living inhabiting fresh,
salt water and dam places. Their body may be naked and covered by pellicle
however in some protozoans the body is covered with shells and often provided
with internal skeleton. Protozoa show different shapes, however spherical,
oval, elongated and often more or less flattened forms are mostly seen. In protozoa
the protoplasm is divided into outer ectoplasm and inner endoplasm. In protozoa
respiration occurs through general body surface by process of diffusion. While
excretion occurs through general body surface but in some there is present a
temporary or permanent pores for this process. Protozoan having contractile
vacuoles to remove the soluble waste matter. Protozoan are having both sexual
and asexual reproduction. Protozoans may be parasite, symbionts or commensals
in nature.
Classification of phylum protozoa
Protozoan are classified into the following
classes;
Supperclass Mastigophora;
The supperclass mastigophora includes a very large number of
minute protozoa which are commonly know as flagellates.
It is further divided into two classes;
Plantlike species or phytomastigophora
Animal like species or zoomastigophora
3. Order Dinoflagellida;
The most characteristics features of the dinoflagellida are
their and flagellar apparatus.
Ex; Ceratium, Noctiluca, Gymnodinium.
4. Order Euglenida;
Euglenida contains those flagellates that store their food
reserve as paramylum. All Euglenida can undergo squirming (Jerky) undulations
know as metaboly, such metabolic movement are not amoeboid movement. There is
mouth and reservoir which contain the roots of flagella and receive the content
of contractile vacuole.
Ex; Euglena, peranema, phacus.
5. Order Volvocida
The volvocida is closely allied to algae. Their body is
covered with a rigid cellulose membrane. These are typically biflagellate forms and most species
are exclusively holophtic and posses a large cup shaped green chromatophores.
Ex; volvex, chlamydomonas,pandornia.
2. Class Zoomastigophora
They are having no chromatophores
however they are having one or many flagella. The species including in this
class are having undulating membrane. Most of them are parasitic and their
reserve food is glycogen. The following order are includes in this class;
Order Rhizomastigida
Order kinetoplastida
Order Diplomonadida
Order Trichomonadida
Order Hypermastigida
All are symbiotic in the rectum of insect predators. They are covered with numerous cilia or flagella. All nuclei are similar in an individual. They are sexuality, with hormones of the host appearing to influence development. They have a covering of cilia of equal length arranged in parallel rows. They are having only one type of nucleus or nuclei, however in some species during mitosis two types of chromosomes have been observed.
4. Superclass sarcodina;
In sarcodina pseudopodia are the organelles of locomotion. They are having predominant amoeboid as well having hard shell. They usually don’t forms spores, formation of gametes and flagellated young ones are common. Most of them are free living and some are parasitic. The sarcodina are divided into classes such as Hydraulea and Autotractea.
Class
Hydraulea;
In the Hydraules all slides of a
pseudopodium have the same direction of movement with respect to the axis of
the pseudopodium. There is no axial structure in pseudopodium. It includes
following order;
Order Amoebida
Order Arcellinida
Order Mycetozoida
Class Autotractea;
In the autotractea the pseudopoda are slender and movement
may occur in opposite directions on opposite sides of the same pseudopodium.
The pseudopodia frequently have axial structures.
v Order protomyxida
Order Heliozoida
Order Radiolarida
Order Foraminiferida
Superclass Apicomplexa;
The supperclass apicomplexan contain one class Telospora with
three orders,they have an apical complex and produce spores that have neither
polar capsule nor polar filament nor vesicular nuclie. The spores are produced
at the termination of the life of trophozoite. Its include two order;
Order Haemospordia
Superclass Myxospora;
The Myxospora includes the sporozoa that produce spores in
each of which one to four polar capsules and each plar capsule a coiled polar
filament. It consist of only one order.
Order Myxosporida.
Superclass Microspora;
The microspore are sporozoa that lacking apical complex. The nuclie
are vesicular as in the Myxospora. When ever polar filament are present they
are brone by very simple spore. The host of Microspora for the both orders are
lower vertebrates and invertebrates. It consist of two orders such as;
Order Haplospordia
Superclass Ciliata;
The ciliate are characterized by the possession of cilia
during a part or whole f their life cycle. In the most ciliate the nuclear
material is separated into a large macronucles and a smaller micronucles. Most
of ciliate are free living in fresh water or the sea. Many of them, however are
ectoparasite and endoparasite of vertebrate and invertebrates. It is divided
into the three classes
Class Kinetofragminophora;
It is characterized by the presence of fragments of kineties
for specialized ciliature.
Class Oligohymenophora;
It is characterized by the presence of complex oral
ciliature.
Class polyhymenophora;
It is characterized by the presence of prominent adoral zone
of buccal membranelles.
0 Reviews