Osteichthyes (Bony fish)

Chondrichthyes (Cartilaginous fish)

Agnatha (Jawless fish)

1. Osteichthyes (Bony fish): Fish with a bony skeleton, such as tilapia, catfish, and salmon.


2. Chondrichthyes (Cartilaginous fish): Fish with a cartilage skeleton, such as sharks and rays.


3. Agnatha (Jawless fish): Fish without jaws, such as lampreys and hagfish.

1. Have a bony skeleton.


2. Possess paired fins and a swim bladder for buoyancy.


3. Scales cover their bodies.


4. Most species have gills for breathing.

1. Have a skeleton made of cartilage, not bone.


2. Possess rough, tooth-like scales (placoid scales).


3. Lack a swim bladder but rely on liver oil for buoyancy.


4. They breathe using gills and have multiple gill slits.

1. Lack jaws and paired fins.


2. Have a smooth, slimy skin and no scales.


3. Their skeleton is made of cartilage.


4. They are often parasitic or scavengers.