Which type of fish is the most primitive?

Cartilage is different from bone because

The lobes of the caudal fin in most sharks are:

These cartilaginous fish live on the bottom, lack a stinging spine and lay eggs

Cycloid scales are thin, flexible and overlapping. What type of fish has them?

Where are shark jaws located to allow for a very streamlined form?

Fish olfactory sacs help fish

What is composed of bony plates and protects bony fish gills?

What do iridophores do for fish coloration?

Fish that live in the open ocean have dark backs, silvery sides and a white belly; this is know as

Fish that spend their lives in the ocean and migrate to fresh water to breed are