In this article we will discuss about Asterias (Starfish):- 1. History of Asterias 2. Habit and Habitat of Asterias 3. External Features 4. Body Wall 5. Endoskeleton 6. Coelom 7. Digestive System 8. Water Vascular System 9. Locomotion 10. Circulatory System 11. Respiratory and Excretory System 12. Nervous System 13. Sense Organs 14. Reproductive System 15. Life History and Development [...]
The following points highlight the ten representative types of Echinodermata. The types are: 1. Antedon 2. Holothuria 3. Cucumaria 4. Thyone 5. Echinus 6. Echinarachinus 7. Echinocardium 8. Astropecten 9. Pentaceros 10. Ophiothrix. Echinodermata: Type # 1. Antedon: Antedon (Fig. 86.1) is commonly known as feather star. Body consists of a central disc or calyx and a series of five [...]
In this article we will discuss about Hemichordata:- 1. General Characters of Hemichordata 2. Classification of Hemichordata. General Characters of Hemichordata: 1. Solitary and colonial, mostly tubicolous, exclusively marine. 2. Body soft, fragile, vermiform and divisible into proboscis, collar and trunk. 3. Body wall with a single-layered epidermis. 4. Coelom enterocoelous, divisible into protocoel, mesocoel and metacoel. 5. Buccal diverticulum, [...]