What Is The Structure Of A Sponge?

A sponge belongs to phylum porifera. Sponges have pores on their bodies. Sponges are primarily marine animal. The ody of the sponge is made up of loosely packed cells and is asymmetrical.
General Characteristics.
The cells are of three types.
1. Pinacocytes
2. Mesenchyme cells
3. Choanocytes
Central cavity is present through which water circulates during feeding.
No tissues or organ system.
Sponges are vase like body. Main opening is called osculum.Excess of water is expelled out from the body through osculum.Body have lots of pore so water enter in the body through pores. Outer surface of the sponge is made up of pinacocytes cells. These are flat cells.
Pinacocytes are specialized into a tube like porocytes. Just below this layer jelly like layer is present called mesohyl. This is made up of loosely packed mesenchyme cells.
The inner most lining of the sponge is made up of choanocytes.These are collar like cells. Collar like portion bears a flagellum. Beating movements of the flagellum move the food particles in to the sponge. Sponges bear an internal skeleton .The skeleton of the sponge is called spicules.Spiclues are amoeboid cells made up of calcium carbonate and silicon.
The inner cavity of the sponge is called spongeocoel.Excess of water is removed from the spongeocoel through the osculum.