Introduction to Fishes

Classificaiton Kingdom Animalia – Phylum Chordata Classes – Agnatha – Chondrichthyes – Osteichthyes

Class Agnatha Most primitive fish class – 7 gill slits The jawless fish Includes hagfish and lampreys

Class Agnatha Structure – Circular mouth – Smooth, scale-less skin – Incomplete cartilaginous skeleton – Prominent notochord

Class Agnatha More structure – Lack paired appendages – Lack upper and lower jaws Have an oral sucker – Used to eat and attach to prey Parasitic

Class Chondrichthyes Cartilaginous fish – Chondros = cartilage, ichthyes = fish – Sharks, skates, rays

Class Chondrichthyes Structure – Full cartilaginous skeleton – Exhibit paired appendages – Loosely articulated lower jaws

Class Chondrichthyes More structure – Skin covered in tooth-like denticles Placoid scales Feel like sandpaper – Protection and speed – No swim bladder Must swim or sink – 5 to 7 gill slits

Class Osteichthyes Bony fish – Osteo = bone Skeletons of bone and cartilage Largest, most numerous fish class Commercially important