1. Bony Fishes – Class Osteichthyes
Skeleton made of bone
Two types of Scales
1) Cycloid scales – smooth
2) Ctenoid scales – tiny spines along their exposed borders

2.                         
Cycloid scales
have
a smooth edge.
                        
Ctenoid scales
have a
toothed edge.

3. Scales are covered by a thin layer of skin and mucus
Mucus is a protective feature
Operculum or gill cover – flap of bony plates and tissue that protects the gills

4. Operculum

5. Homocercal tail: Upper and lower lobes of the tail are the same size
Fin Rays consist of thin membranes that are supported by bony spines

6. Homocercal Tail Types

7. Mouth is terminal and located at the anterior end

8. Jaws are protrusible because they can be projected outward from the mouth
Teeth attached to the jaw bones and replaced from below

9. Swim bladder – gas-filled sac just above the stomach and small intestines – allows the fish to adjust its buoyancy to keep from sinking or rising