Chordata

1. Chordata

2. Phylum Chordata Subphylum Urochordata Subphylum Cephalochordata Subphylum Vertebrata Agnathans Fish Sharks tetrapods tunicates lancets

3. Characteristics of Chordates

4. Possible evolution of 1st fish 1st fish lancelet Proto-vertebrate Adult tunicate Tunicate larvae

6. Early Chordate ancestor may have given rise to 1st vertebrate Pikaia Burgess Shale Fauna Cambrian 540-500 mya

7. General Features Shared by Chordates: • Eukaryote • Multicellular • Bilateral- deuterstomes • Heterotrophic

8. Phylum Chordata Subphylum Urochordata - Tunicates Class Ascidiacea - Sea Squirts Solitary e.g. Styela montereyensis Colonial - in groups but with own tunic Compound Colonial - colonial with shared tunic Class Thaliacea - Salps (free swimming), planktonic Class Larvacea - Gelatinous house, planktonic

9. Subphylum Urochordata tunicate

10. Subphylum Urochordata = tunicate • Tunicate - also called 'sea squirt' • notochord is confined to the tail • notochord is lost during metamorphosis into sessile adult • possess pharyngeal slits • Repro- sexual (hermaphroditic) & asexual (budding)

11. Tunicate Adult Anatomy

12. Tunicates: • Free swimming larva: • notochord present only in free-swimming  larvum • notochord does not extend into head • larvum is free-swimming but non-feeding • adult is sessile filter feeder • Settled larva: • Settle after brief free-swimming larvum existence.  • Attaches at anterior end.  • Metamorphosis begins.  • Body turns 1800.  • Tail, notochord, dorsal nerve cord, disappear.

14. Class Larvacea - planktonic Oikopleura

15. Class Larvacea - Gelatinous house, planktonic Jelly-like house Oikopleura Marine snow

16. Class Thaliacea - Salps (free swimming), planktonic Pyrosoma- bioluminescent Colonial salp

17. Class Ascidiacea - Sea Squirts

18. Subphylum Cephalochordata lancet • Strictly marine • Live buried in sand with head sticking out • Filter feeders

19. Lancet Anatomy

20. Vertebrate Higher Classification • Superclass Agnatha - without jaws • Class Myxini – hagfishes • Class Cephalaspidomorphi – lampreys • Superclass Gnathostomata – with jaws • Class Chondrichthyes – sharks, rays, chimaeras • Class Actinopterygii – ray-finned fishes • Class Sarcopterygii – lobe-fin fishes • Class Amphibia – frogs, salamanders • Class Reptilia – snakes, lizards, crocodiles • Class Aves - birds • Class Mammalia - mammals

21. Lack: paired fins, scales, & well developed vertebrae Hagfish (slime eels) Mucus for protection Feed on decaying flesh Lampreys Parasitic Anadromous Marine adults, breed in freshwater Agnatha (jawless fishes)

22. Class Chondrichthyes Subphylum Vertebrata Sharks, skates, rays, chimera

23. Heterocercal tail Two dorsal fins Paired pectorals 5-7 gill slits ureoosmotic Chondrichthyes (cartilagenous fishes)

25. Swim bladder Operculum (gill cover) Homocercal tail Scales of bony origin Smooth cycloid Spiny ctenoid Osteichthyes (bony fishes)

26. Swim bladder Dorsal fin Adipose fin (characteristic of trout) Caudal fin Spinal cord Brain Nostril Anal fin Cut edge of operculum Lateral line Liver Gills Anus Gonad Heart Stomach Urinary bladder Pelvic fin Kidney Intestine

27. Class Amphibia Characteristics • Cold blooded • Returns to water to breed • Metamorphosis • Some toxic • Estivation-dry and hot • Hibernation- cold 3,500 species

28. Class Amphibia Mudpuppy (salamander) newt salamander Poison arrow frog Rana cancrivora Coqui

29. Class Reptilia Characteristics • Cold blooded • Have scales • Amniotic egg • Dry skin • 3 chambered heart (except crocks) 6,500 species

30. Class Reptilia Marine iguana Saltwater crocodile Marine turtle Sea snake

31. Class Aves Characteristics • Warm blooded • Feathers and wings • Hollow bones • Horny bill • Lungs have air sacks • Hard egg shell

32. Class Aves

33. Class Mammalia Characteristics • Warm blooded • Have fur or hair • Suckle young • 3 middle ear bones

34. Class Mammalia Subclasses • Protheria- echidna & platypus • Metatheria- marsupial • Eutheria- true mammals