Chapter 3 Section 2

Fish Largest group of vertebrates Fish: Ectothermic vertebrate Lives in water Has fins to use for movement Obtain oxygen through gills Have scales to cover the skin

Obtaining Oxygen How and where do fish get their oxygen? The water contains oxygen Water moves through the fishes throat to the gills Gills have blood vessels in them

Obtaining Oxygen Water flows over the gills Oxygen moves from the water into the blood Carbon dioxide moves out of the blood and into the water The water leaves by flowing out the slits beneath the gills

Circulatory System From the gills: Blood travels throughout the body in vessels Blood travels to all regions of the body Oxygen is supplied to the cells

Circulatory System What type of circulatory system do they have? Closed The heart pumps the blood ->

Moving and Feeding How do fish move? Using a fin A fin is a thin membrane stretched over a bony support Provides a large surface to push against the water

Moving and Feeding What are the bodies of fish adapted to do? Efficient feeding Barracuda Sharp and pointed teeth Why would they want sharp teeth?

Moving and Feeding What type of teeth do trout have? Short and blunt teeth What type of teeth do basking sharks have? Comb-like structures to filter tiny animals

Nervous system and Senses Why would fish want to have a highly developed nervous system and senses? Find food Avoid predators Touch, taste, smell, and sight help them capture their food A shark can smell and taste one drop of blood in 115 liters of water

Reproduction How do they reproduce? Externally Male hovers close to the female Releases a cloud of sperm over the released eggs Sharks and guppies have internal fertilization

Groups of Fish What are the three groups of fish? Jawless Cartilaginous Bony How are they classified? Structure of their mouth and type of skeleton

Jawless Fish Jawless fish information Do not have a pair of fins Earliest vertebrates 60 species today Modern jawless fishes have no scales Skeletons made of cartilage Do not have a pair of fins Do not have jaws – can’t bite

Lamprey

Jawless fish How do they eat without a jaw? Have structures for scraping, stabbing, and sucking What are the only kinds of jawless fish? Hagfish and lamprey

Hagfish

Jawless Fish Hagfish Lamprey Large, slimy looking worms Crawl into the bodies of dead or dying fish Use their sandpaper tongue to consume decaying tissue Lamprey Parasites to other fish Attach to healthy fishes and suck in the tissues and blood of their victims

Cartilaginous Fishes What are their skeletons made of? Cartilage like jawless fish What makes them different from jawless fish then? Have jaws Have a pair of fins

Cartilaginous Fishes Information on cartilaginous fishes Pointed, tooth-like scales Have a texture rougher than sandpaper All are carnivores Rays and skates live on the ocean floor Sharks, rays, and skates are all types

White Shark

Barndoor Skate

Blue-Spotted Ray

Shark’s Body How would you describe a shark? Stream lined body Mouth on the bottom of its head Jagged teeth arranged in rows Use only the 1st row of teeth

On the Move How do sharks get oxygen? Rely on currents to get water across their gills Position themselves in currents to get water over their gills at night What do sharks spend most of their time doing? Hunting Attack and eat nearly anything that smells like food Have bad eye sight

Sleeping Shark

Bony Fishes What are types of bony fish? Trout Tuna Goldfish What is different about bony fish? Have a pocket over their gills

Bony Fish

Swim Bladder How do fish swim at different depths? Swim bladder: Gas-filled sac that allows them to stabilize their body at different depths Filled with oxygen, nitrogen, and carbon dioxide Volume of gas can become larger or smaller Change in volume changes the buoyant force

Swim Bladder Buoyant Force: Force that water exerts upward on an underwater object If the buoyant force is greater than the weight of the object it floats If the buoyant force is less than the weight of the object it sinks

Diversity of Bony Fish Make up 95 % of all species of fish Live in salt and fresh water

Sea Dragon

Flying Gurnards

Clownfish

Balloon fish

Bluefin Tuna

Trout