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 scalesSkeleton is made of cartilage3 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