Saturday, September 10, 2011

Introduction of Porifera with characteristics


Porifera

These includes the animals which are more developed than protozoa. These are animals whose bodies are provided with pores through out its bodies. This includes animal which are found in water in seas. They are fixed to the substratum.
Some of the properties of porifera are listed below.
1)    They are multicellular animals found in water fixed to the substratum.
2)    The body of these animals are provided with pores through out it.
3)     The mouth of it is called osculum.
4)    They have well developed  circulating system
5)    They have well developed canal system.
6) All of them have definite shape and size except amoeba. Some are
     Cylindrical, vase shaped ,tree like , leaf like, cushion shaped, rope like and
      Bowl shaped.
7) They may live solitary or colonial life.
8) Their bodies are generally asymmetrical but few are radially symmetrical.
9) They are found in different colours but more of them are reported to be white and   grey .Some of them are also green in colour due to presence of symbiotic algae with them.
10) They have well developed canal system for nutrition ,excretion, respiration and reproduction. There are three types of canal systems .They are named as Asconoid type, syconoid type and leuconoid type.
11) They have skeleton in them which are called Pseudoskeleton (formded by foreign body) and Autoskeleton (formed by elements secreted by themselves)
12) They reproduce asexually by regeneration and budding and sexually by the formation of sex cells which fuse to form zygote.
Example sycon, sponge
Sycon
sycon

sponge

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