what are the characteristics of phylum porifera?
Answers
Answer:
They are generally marine aquatic organisms, with a few freshwater species.
Their bodies are asymmetrical.
Body shape can be cylindrical, vase-like, rounded or sac-like.
They are diploblastic animals with two layers, the outer dermal layer and the inner gastral layer.
Phylum- Porifera
1. These animals are with simplest body plan and are called as 'Sponges'. They bear numerous pores on their body. Those pores are called as 'Ostia' and 'Oscula',
2. These are aquatic animals. Most of them are marine and few are fresh water dwellers.
3. Most of the animals have asymmetrical body.
4. These animals have special types of cells-collar cells.
5. These animals are always attached to substratum, hence do not show locomotion. Hence, they are referred as sedentary animals.
6. Their spongy body is supported by spicules or spongin fibres. Spicules are made up of calcium carbonate or silica.
7. These animals feed upon small organisms taken in their body along with water. Water is taken in through ostia and given out through oscula.
8. These animals reproduce by budding, an asexual method and / or by sexual method. Besides, they have good ability of regeneration.
Examples: Sycon, Euspongia (Bath sponge), Hyalonema, Euplectella, etc.