Learning Log What are the 3 types of fishes?

Answer -Bony Fishes -Jawless Fishes -Cartilaginous Fishes

Chapter 3 Section 2 Types of Fishes: Jawless, Cartilaginous, Bony

3 Main Groups Jawless Cartilaginous Bony Organized into groups based on: - structures of their mouths - types of skeletons

Characteristics of Jawless Fishes No jaw, No scales Mouths contain structures for scraping, stabbing and sucking their food Skeleton is made of cartilage

Examples of Jawless Fishes Hagfishes and lampreys – only kind that exist today Hagfishes: look like large, slimy worms Lampreys: many are parasites of other fishes

Characteristics of Cartilaginous Fishes Have jaws and scales Skeleton is made of cartilage 3 Major Groups: - Sharks -Skates -Rays

Sharks All sharks, except the bull shark, live in salt water Range in length from 15 cm to ~20 meters Paired Fins – Help change direction as it swims Swim constantly to take in oxygen for respiration Many are predators/meat eaters – feed on squid Excellent sense of smell – 1 drop of blood per 25 gallons Can sense lateral movement in water using a series of pits called the lateral line on its sides

Rays and Skates Flat, wide bodies, long thin tails Pectoral fins on their sides – look like wings Obtain oxygen by swimming in water, which moves over their gills Take in water through a pair of openings called spiracles Generally harmless, some have sharp poisonous tail spines for defense; Stepping on or touching one of these rays or skates could be dangerous

Characteristics of Bony Fishes Bony Fishes make up ~95% of all fish species Have jaws and scales Have a pocket on each side of the head that holds the gills – Gill pockets are covered by a flap that opens to release water Skeleton is made of hard bones Live in salt and fresh water Live at dark depths and light-filled waters

Major Structures of a Bony Fish Scales Fins for balance Tail fin Swim Bladder: internal, gas filled sack that helps the fish stay stable at different depths in the water -Adjusting gas levels allow the fish to stay at a depth without using a lot of energy