![Refrences
Websites
https://www.britannica.com [11am] [12/5/23]
https://www.greeksforgreeks.org [3 pm] [12/5/23]
https://www.biologydiscussion.com [5 pm] [13/5/23]
https://www.sciencedirect.com [7 pm] [ 13/5/23]
https://www.journals.uchicago.edu [8pm] [13/5/23]
Books
Zoology by Stephen A. Miller and John P. Harley , fifth
edition , chapter no.17, page no. 255- 265
Zoology By Stephen A Miller and John P. Harley , tenth](https://image.slidesharecdn.com/hemi-230703064356-54e3c207/85/hemi-4-pptx-25-320.jpg)
hemi.4.pptx
- 1. CLASSIFICATION OF HEMICHORDATES PRESENTED BY: HADIA IFTIKHAR ROLL # 22011514-004 BS-ZOOOLOGY DEPARTMENT OF ZOOLOGY
- 2. CONTENTS • PHYLUM HEMICHORDATA • CLASSIFICATION OF HEMICHORDATA • CLASS ENTERONEUSTA • General Characters • Maintainance Functions • CLASS PTEROBRANCHIA • General Characters • Maintainance Functions • CLASS PLANCTOSPHAEROIDEA • REFRENCES
- 3. PHYLUM HEMICHORDATA hemi,half+chorda,cord Habitat ; Marine Environment Deuterostomates (anus develops first)
- 4. General Characters Half Cord Triploblastic Ciliated Pharynge al Slits Open Circulatory System Complete Digestive System Dorsal or tubular nerve cord Dioecious Organisms
- 5. cont... They have three body regions Probocis Collar Trunk
- 7. CLASS ENTEROPNEUSTA • 70 Species • 10-40 cm long • some about 2m long • U-shaped burrows • acorn worms
- 8. GENERAL CHARACTERS • Marine Habitat • Ciliated Pharyngeal Slits • Open Circulatory System • Complete igestive Tract • Proboscis;short and conical projection at the anterior end • Collar; ring like • Trunk ; elongated • Ciliated epidermis and gland cells
- 9. Maintainance Functions • Feeding • probocis • cilia • mucous • mucoid string • Pharyngeal slits
- 10. Cont... Digestion • Simple tube • hepatic sacs • complete digestive system • from mouth to anus
- 11. Respiration • Diffusion • Pharyngeal Slits • diffusion (blood and water) Excretion • Pores in collar • Ammonia • Diffusion • Through anus
- 12. Cont... Circulatory System • 1 dorsal and 1 ventral blood vessel • anteriorly and posteriorly circulates • blood colorless • distributes nutrients • open circulatory system • Glomerulus Nervous System • ectodermal in origin • a dorsal and a ventral nerve cord • neve plexus • no major ganglia • sensory receptors
- 13. cont... Reproduction and development • Dioecious • 2 rows of gonads • external fertilization • tornaria larvae
- 14. CLASS PTEROBRANCHIA • deep oceans • 20 species • 0.1 to 5 mm long • form asexual colony
- 15. GENERAL CHARACTERS • Triploblastic • 3 body regions • probocis; shield- like • Collar ; 2-9 arms and tentacles • Trunk; U- shaped • Complete digestive tract • Open Circulatory System • Dioecious
- 16. MAINTAINANCE FUNCTIONS Feeding • Cilia • mucoid string • Arms • Tentacles • filter feeding
- 17. Digestion • U-shaped • complete digestive tract • mouth to anus • enzymes in stomach • digestion and absorption
- 18. cont... Excretion • ammonia • diffusion • anus (the last part of digrstive tract) Respiration • Gills • pharyngeal slits
- 19. Cont.... Circulatory System • Contractile Heart- like blood vessel • sinuses • open circulatory system. Nervous System • no proper system • intra-epidermal • concentration of nerves at the base of tentacles
- 20. Cont...
- 21. Cont.... Reproduction and development • Dioecious • Asexual colony • Sexualy also • External fertilization • Planula- like larvae • Tube of female • Metamorphosis • Adult
- 23. Class Planctosphaeroidea • 1 Specie • P. pelagia • U-Shaped digestive tract • cilia band for food capturing • Mucous secreting gland • feeding • deterring predators and parasites • Free swimming larvae • Tornaria • similar to Enteropneusta’s larvae but large in size .
- 24. Cont...
- 25. Refrences Websites https://www.britannica.com [11am] [12/5/23] https://www.greeksforgreeks.org [3 pm] [12/5/23] https://www.biologydiscussion.com [5 pm] [13/5/23] https://www.sciencedirect.com [7 pm] [ 13/5/23] https://www.journals.uchicago.edu [8pm] [13/5/23] Books Zoology by Stephen A. Miller and John P. Harley , fifth edition , chapter no.17, page no. 255- 265 Zoology By Stephen A Miller and John P. Harley , tenth
- 26. QUESTIONS???