1. Sienna Navarro 9B

2. Meaning It comes from the Greek words chondr and ichthyes = cartilaginous fish cartilage fish

3. First Fossil Comes from the early Devonian age 416 million years ago Elasmobranches: Cladoselache

4. Number of Species 934 species: 383 species of sharks 516 species of rays 35 species of chimaeras

5. Characteristics Endoskeleton entirely cartilaginous Tough skin covered in dermal denticles No Swim Bladder Two chambered heart Acute senses Sharks shed and replace teeth

6. Life Cycle & Expectancy Average life expectancy: 20-50 years Longest living species: whale shark 100-150 years 3 types of embryonic development: Oviparous: egg birth Ovoviviparous: live egg birth Viviparous: live birth

7. Oviparous- egg birth Female shark deposits eggs cases in sea Developing embryo receives nutrients from a yolk formed prior to fertilization

8. Ovoviparous- live egg birth Female retains membrane covered eggs Embryo sheds membrane develops in uterus Some species receive nutrients from direct lining Other species the embryo obtains nutrients by swallowing eggs / other embryos

9. Viviparous- live birth Embryo and attached yolk grow in uterus Outside layer of yolk contacts mothers uterus Receives nutrients

10. Digestive System Swallow food whole or in large pieces Strong acids and enzymes used to dissolve food Creates liquid mush Nutrients absorbed in intestine Indigestible things are vomited

11. Respiratory System Species breathe through 5-7 gills Pelagic fish must continue swimming to keep oxygenated water moving though their gills Demersal fish pump water in through spiracles; out through gills

12. Circulatory System Closed circulatory system Two chambered heart: Atrium Ventricle Atrium pumps blood to ventricle Venticle pumps blood to conus Blood travels from conus to gills Oxygenated blood flows through body Blood returns to atrium

13. Sensory System One inner ear Detects sound, acceleration, gravity Lateral line Eye sight Sensitive to light and moving objects Smell Very acute Not connected with the mouth Barbels: responsive to chemical movement

15. Meaning: It translates to no jaws Number of Species 84 species Lampreys Hagfish First Fossil Appeared during Cambrian period: 524 million years ago Myllokunmingia

16. Characteristics Jaws are absent No appendages 7+ gill pouches The digestive system lacks a stomach Cartilaginous skeleton Two chambered hearts Slender, eel-shaped body Notochord persists in adults Provides support

17. Lamprey: Life Cycle & Expectancy Eggs hatch - become larvae Larvae live in river mud from 3-10+ years Feed off of decaying organisms and fecal matter Metamorphic Phase(3-4m) / Migrate to sea (12-20m) Develop teeth on sucking disks Spawning Phase (3m) / Death Lay eggs Die within the month spawning

18. Lamprey: Digestive System Attack prey Attach mouth to preys body Cut through the skin and scales Food = fish blood Mouth Pharynx Esophagus Esophagus directly to intestine (nutrients absorbed) Waste released through anus Dual immune defense system

19. Hagfish: Life Cycle & Expectancy Little is knows of hagfish life span Born fully developed Hermaphroditic Choose sex during mating season (can alternate) Females lay small number of eggs for their size Live in numbers as large as 15,000

20. Hagfish: Diet & Digestive System Scavenger Eats dead animals Devours from inside out Absorb nutrients through their skin and gills Mouth is designed to tear flesh Slow metabolism Can survive months between feedings Food is enclosed in permeable membrane Waste is excreted

21. Respiratory System Cutaneous Respiration Diffusion Dissolved oxygen diffuses into blood Carbon dioxide diffuses out

22. Sensory System 10 cranial nerves No external ears No eyelids Hagfish: Poor vision Releases slimy mucus when in danger Lateral line system (sense water currents/vibrations) Lamprey: Lateral line system Medial nostril (smell perceiving chemicals in water) Pineal organ (perceives light/dark)