What are cartilaginous fish

1. What makes cartilaginous fish different from other fish? Give examples.

-their Skeletons are made of cartilage.

2. List examples of cartilaginous fish.

-Skates

-rays

-shark.

3. What is special about the sharks eye?

-they have good vision in dim light. their pupil can dilate and contrast to control the incoming light.

4. What are the differences between bony fish and cartilaginous fish:

a. Heart and Blood - Sharks have fewer red blood cells,sharks have no bone marrow

b. External features - Shark skin is covered by dermal denticles. Bony fish are covered in flat scales.

c. Digesting and Evacuation - Bony fish have two seprate openings, sharks have only one opening called the cloaca.