1. Shark Notes: Class Chondrichthyes

2. 368 different species including
Diversity
368 different species including
rays & skates.

3. Shark Anatomy
Bodies covered in sandpaper-like tiny placoid scales for protection.
Placoid scales under a microscope
No swim bladder for buoyancy, so they must stay moving or they will sink.

4. Shark Anatomy
5-7 gill slits on each side of the body that are not covered with an operculum.
40+ teeth in a jaw, plus 7 extra rows of developing teeth behind them.

5. Shark Reproduction
Sharks reproduce sexually. Male sharks have claspers on their belly.
Click!

6. Sharks can be born in 3 ways:
1. Eggs are laid (like birds)
Horn’s Shark egg Swell Shark egg

7. Sharks can be born in 3 ways:
2. Eggs hatch inside the mother & then are born

8. Sharks can be born in 3 ways:
3. Pup sharks grow inside
the mother (like humans)
Click!

9. Ancient Sharks Megalodon! 40+ ft long based on tooth fossils.
Lived mya.
Probably ate whales.

10. Sharks in Medicine
Sharks are resistant to cancer & disease, so research is being done on shark cartilage. =

11. Biggest Threat to Sharks: Shark Fin Soup