Chordata

Chordata is the last phylum of kingdom Animalia.
Which is further subdivided into subphylums, divisions and classes.
The Slides shows the classification of the phylum along with the basis on which it is classified.
(includes examples along with pictures for easy understanding and memorizing)

1. CHORDATES PPT made by HETAKUMARI PILUDARIA Bsc (HONS) Biotechnology Sem 4 Guided by Dr. Ravneet Chug

2. CONTENTS GENERAL CLASSIFICATION OUTLINE CLASSIFICATION

3. CHORDATA Derived from Greek word chorde means string or cord ata means bearing

4. Diversity of chordata 64832 species on record 32120 fishes 6771 amphibians 9320 reptiles 9026 birds 5750 Mammals smallest - 10mm [philippine gody] largest - 35 m Blue Whale]

5. GENERAL CHARACTERISTICS Aquatic, terrestrial or aerial. All free living. no parasitic bilaterally symmetrical Presence of post anal tail Exoskeleton Triploblastic True coelom Cartilaginous or bony endoskeleton

6. Pharyngeal gill slits at some stage, may/may not be functional] Complete digestive system Closed blood vascular system Excretory system - proto/meso/ metanephric kidneys Dorsal and tubular nerve cord Disexual

7. Fundamental Chordates Characteristics Dorsal hollow or tubular nerve cord longitudinally supporting rod like notochord pharyngeal gill slits

8. Dorsal hollow nerve cord CNS is present dorsally Longitudinal hollow nerve tube Above notochord

9. Notochord Notochord is elongated Rod like Flexible Present beneath nerve cord Prime feature of chordates

10. Pharyngeal gill slits At some stage Paired lateral gill slits Pharyngeal wall of gut behind mouth Protochordates - present throughout life Higher vertebrates - disappear / modifies in adult

11. CLASSIFICATION On the basis of - Presence of notochord or vertebral column Presence or absence of Cranium

12. GROUP A: Acrania (protochordata) All marine Primitive Lacks head/skull/cranium Divided into three subphylum Hemichordata Urochordata Cephalochordata

13. Subphylum I. Hemichordata Body division : Proboscis, collar and trunk Notochord short; confined to proboscis Have 4 classes

14. Class I: Enteropneusta Worm like body Numerous gill slits Straight intestine Also known as tongue worms Balanoglossus

15. Cephalodiscus Class II: Pterobranchia Small compact body One pair of gill slit or absent U shaped intestine

16. Class II: Planctosphaeroidea Round and transparent Branched ciliary bands L shaped alimentary canal Class IV: Graptolita Were present in abundant in Ordovician and silurian period The extinct class of Hemichordata tubular chitinous skeleton Dendrograptus [graptolita]

17. Subphylum II. Urochordata / Tunicata Notochord in larval stage only Adult sac like Sessile Encased in protective tunic Divided into 3 classes Ascidiacea Thaliacea Larvacea/Appendicularia

18. Class I: Ascidiae Sessile Scattered muscles in tunic Solitary / colonial / compound Gill clefts numerous Herdmania

19. Scalpa [Thaliacea] Oikopleura [Larvaceae] Class II: Thaliacea Free swimming Circular muscles in tunic CLass III: Larvacea / Appendicularia Tiny, Transparent Free floating

20. Subphylum III. Cephalochordata Notochord and nerve cord present throughout life along entire length body Class Leptocardii Body fish like Segmented with distinct myotomes a nd numerous gill-slits Have one family, 2 genera and 30 species Asymmetron

21. Group B: Craniata / Euchordata Aquatic terrestrial With distinct head Vertebral column Jaws Brain protected by skull or cranium

22. Subphylum IV. Vertebrata Notochord replaced by vertebral column Body divisible into head,neck, trunk and tail Largest subphylum with 46500 species Two Divisions Agnatha Gnathostomata

23. DIVISION I: Agnatha Jawless primitive fish Without true jaws Paired limbs Have 3 classes Class I: Ostracodermi The extinct order Primitive heavily armoured The first vertebrate Cephalapsis

24. Class II: Cyclostomata Eel shaped Without scales, jaws and lateral fins Mouth round and suctorial Myxine

25. DIVISION II: Gnathostomata True jaws Paired limbs Have two superclasses Pisces Tetrapoda

26. Superclass I: Pisces Scaly skin Gills Paired fins Have 3 classes Class I: Placodermi Primitive Jawed fishes Bony heads Climatius

27. Class II: Chondrichthyes Cartilaginous endoskeleton Placoid scales Gill slits not covered with operculum Pelvic claspers in males Selachimorpha

28. Hippocampus Class III: Osteichthyes Bony endoskeleton cycloid/ ctenoid scales Gill slits covered with operculum Males without claspers

29. Superclass II: Tetrapoda Land vertebrate Two pairs of pentadactyle limbs Cornified skin and lungs Have 4 classes

30. Class I: Amphibia Aquatic larval stage Larva have gills Adults terrestrial Adults breathe through lungs Moist skin 3 chambered heart Ambystoma [ salamander]

31. Class II: Reptilia Terrestrial Dry skin Horny scales Heart incomplete 4 chambered Cold blooded Respiration by lungs Crocodylinea

32. Class III: Aves Flying vertebrate Covered with feathers Forelimbs modified into wings No teeth in beak 4 chambered heart Warm blooded Pavo cristatus

33. Class IV: Mammalia Body covered with hair Glandular skin Female with mammary glands 4 chambered heart Warm blooded Panthera leo

34. THANK YOU