CHONDRICHTHYES

The Cartilage Fishp. 291-294

Characteristics:

- Skeletons of cartilage- Tooth-like scales (placoid)- Sharks, skates, rays- Replaceable teeth- First to show paired fins- Swim to maintain buoyancy (lack swim bladder)

External Anatomy Fusiform body Placoid scales Spiracles Lateral line

Detect changes in water pressure and chemistry

Fins: Pectoral Pelvic Dorsal Caudal Anal

Internal Anatomy

Lorenzini pores in nostril

Intestinal spiral valve Slows passage of

food for increase absorption

Fertilization

Internal fertilization Oviparous (egg) Oviviparous (egg hatches inside body

and young born live but without placental attachment)

Viviparous (live birth)

* All three found in species of sharks, skates, and rays

Bull Shark

Hammerhead Shark

Great White Shark

Whale Shark

Frilled Shark

Goblin Shark

Megalodon - Prehistoric

Giant Stingray

Stingray

Sawtooth

Manta Ray