Urochordata includes about 2000 fixed and 100 pelagic species. It has been divided into the following three classes: Class 1. Larvacea (Appendicularia): 1. Small (5 mm long solitary) free-swimming pelagic forms. 2. Neotenic forms which retain the larval form throughout adult life with persistent tail, nerve cord, notochord. 3. Test is temporary and renewed periodically. 4. Single pair of gill-slits [...]
The following points highlight the nine main types of urochordata. The types are: 1. Molgula 2. Botryllus 3. Ascidia 4. Ciona 5. Clavelina 6. Pyrosoma 7. Doliolum 8. Salpa 9. Oikopleura. Type # 1. Molgula: Molgula (Fig. 5.1) is a round, solitary and sessile ascidian, about 2.5 cm long. It is found abundantly in the shallow water of Atlantic and [...]
In this article we will discuss about:- 1. External Features of Ascidia 2. Body Wall and Atrial Cavity of Ascidia 3. Digestive and Respiratory System 4. Respiration 5. Blood Vascular System 6. Excretory System 7. Nervous System 8. Reproductive System 9. Metamorphosis. Contents: External Features of Ascidia Body Wall and Atrial Cavity of Ascidia Digestive and Respiratory System of Ascidia [...]