In this article we will discuss about:- 1. Description of Branchiostoma 2. External Features of Branchiostoma 3. Body Wall 4. Skeletal System 5. Locomotion 6. Digestive System 7. Respiratory and Feeding Mechanism 8. Blood Vascular System 9. Excretory System 10. Nervous System 11. Reproductive System. Contents: Description of Branchiostoma External Features of Branchiostoma Body Wall of Branchiostoma Skeletal System of [...]
In this article we will discuss about the affinities of branchiostoma. Affinities # Branchiostoma with Mollusca: Molluscs and Branchiostoma differ widely. Superficial resemblances in ciliary feeding and respiratory mechanism (no gill slits in molluscs) have no phylogenetic significance. Affinities # Branchiostoma with Echinodermata: Similarities: 1. Early development cleavage, gastrulation and mesoderm formation. 2. Three separate enterocoelic cavities. 3. The pores [...]
In this article we will discuss about the classification of subphylum acrania. 1. Lack distinct head, cranium, brain, eyes, auditory organs and jaws. 2. The nerve cord is dorsal and hollow. 3. Notochord persistent and extends along the whole length of the body. 4. Gill slits numerous and open in the atrium. 5. Blood vascular system and nervous system resemble [...]