In this article we will discuss about Sagitta:- 1. Habit and Habitat of Sagitta 2. External Structures of Sagitta 3. Body Wall 4. Coelom 5. Digestive System 6. Circulatory, Respiratory and Excretory Systems 7. Nervous System 8. Reproductive System 9. Development. Habit and Habitat of Sagitta: Sagitta is a marine planktonic animal which lives throughout […]