Provides information on, and photographs of, the primitive fish classes. Discusses the Superclass Agnatha, the Class Chondrichthyes, and the Osteichthyes. Very interesting, with lots of pictures!

Describes the anatomy of a fish's circulatory system and how the blood circulates in a fish.

Dive into the biology of most fish to understand why they can only breathe while in the water. Does every fish meet its death when they are out of water?

Educational site offers an illustration of the salmon life cycle as well as information on salmon reproduction, adaptation to salt water, life span, diet, anatomy, predators and more.

A glossary for terms relating specifically to sharks, many of which are relevant to the entire chondrichthyes class.

This site is all about sharks including information on teeth, skeleton, diet, evolution, and more. Includes worksheets and printouts.