In this article we will discuss about Spicules:- 1. Meaning of Spicules 2. Classification of Spicules 3. Development 4. Taxonomic Importance. Meaning of Spicules: The spicules or sclerites are definite bodies, having a crystalline appearance and consisting in general of simple spines or of spines radiating from a point. They have an axis of organic material around which is deposited [...]
The following points highlight the eleven representative types of Sponges. The types are: 1. Euplectella 2. Hyalonema 3. Pheronema 4. Oscarella 5. Cliona 6. Tethya 7. Halichondria 8. Spongilla 9. Chalina 10. Euspongia 11. Hippospongia. Type # 1. Euplectella: Euplectella aspergillum (Fig. 27.1) is commonly known as Venus' flower basket. It is a glass sponge. The body is cylindrical and [...]
The below mentioned article provides a detailed account of Metazoa. Protozoa are acellular animals of small size, they have a permeable limiting membrane which prevents the animals from growing beyond a certain size, and it precludes the formation of structures which will give strength and rigidity necessary for large size. But more important than strength is the factor that the [...]