Phylum Porifera (Sponges)
Members of this phylum are commonly known as sponges.
They are mostly marine, few are found in fresh water.
Mostly are assymetrical animals, no definite shape to the body.
These are primitive animals, multicellular with cellular grade of organization.
Adult sponges are sessile, that is they need a substratum to attach themselves to a surface and do not move.
Due to the sessile nature, sponges are filter feeders.
Digestion is intracellular.
The body of sponges is supported by a skeleton made of spicules or spongin fibres.
Sexes are not separate, they are hermaphrodites. Hermaphroditism - condition where eggs and sperms are produced by the same individual.Sponges reproduces asexually by fragmentation and sexually by formation of gametes.
Fertilization is internal.
Indirect development, having a larval stage which is morphologically distinct from the adult.
- Water transport or Canal system -
Sponges have water transport system. Water enters through minute pores (ostia) in the body wall into a central cavity known as spongocoel. From the spongocoel water goes out through the osculum. This water system aids in food gathering, respiratory exchange and removal of wastes.
These are collar cells, they line the spongocoel and the canals.
- Examples: Sycon, Euspongia, Spongilla.
Classification of Phylum Protozoa:-
Phylum Protozoa divided into two sub-phylums
1. Sub Phylum Plasmodroma
2. Sub Phylum Ciliophora
1. Sub Phylum Plasmodroma
This sub phulum is further divided into 6 super classes.
1. Mastigophora
this divided into 2 classes
a. Phytomastigophora
b. Zoomastigophora
2. Opalinata
3.Sarcodina
this is also divided into 2 classes
a. Hydrailea
b. Autotractea
4.Apicomplexa
5.Mesospora or Myxospora
6. Microspora
2. Sub Phylum Ciliophora
This sub phylum divided into 1 super class.
Super class Ciliata
which is further divided into 3 classes
1. Kinetofragmenophora
2.Oligohymenophora
3. Polyhymenophora
