Deuterostome Lab

1. Deuterostomes
• First embryonic opening becomes the anus
• Includes the phyla Echinodermata and Chordata

2. Echinodermata
• Marine animals
• Bilateral symmetry (larvae)
• Three tissue layers
• Coelomates
• Hard exoskeleton
– Name means “spiny skinned”
• Movement: water vascular
system
– Tube feet that create or release
suction
• Today: Dissect starfish

3. Examples of bilateral larvae

6. Chordata
• Not all chordates are vertebrates
• Chordates have the following characteristics as
embryos:
• Dorsal (back) tubular nerve cord
• A notochord
– Supportive rod
• A post anal tail
• Pharyngeal pouches that become gill slits

7. Visual of chordate characteristics

8. Tunicates (Urochordates)
• Invertebrate chordates
• Adults maintain gill slits
• Observe pictures and
models in lab

9. Cephalochordates
• Invertebrates
• Lancelet example
• Adult has all 4
characteristics
• Observe pictures and
models in lab

10. Vertebrate Innovations
• Vertebral column
• Segementation and
specialization
• Complex brain and cephalization
• Jaws
• Paired fins, gave rise to limbs
• Gills, evolved into lungs

11. Today: Frog
•Amphibian
•First vertebrate able
to live on land
• Important external structures:
– Tympanum: internal ear/eardrum
– Nares: nostril/breathing hole

12. Frog Mouth
• Eustacian tube: leads to
ears
• Maxillary and vomerine
teeth
• Glottis: opens to larnyx,
vocal cords
• Esophogus: leads to
stomach

13. Internal Frog
• If female, find ovaries with eggs
• Identify two lungs (partially hidden by liver)

14. Internal Frog Continued
• Liver and
gallbladder
• Esophagus and
stomach
• Small and large
intestines

15. Internal Frog Continued
• Pancreas and spleen
• Fat bodies: store fat

16. Internal Frog Continued
• Heart covered by pericardium
– Three chambers (1 ventricle, 2 atria)

17. Internal Frog Continued
•Kidneys (long and narrow)
• Testes (yellow and oval)
• Mesonephric ducts: carry urine
•Cloaca: opening
to outside