The backbone is part of theENDOSKELETON (internalskeleton). It’s job:•SUPPORT•PROTECT•GIVES BODY SHAPE•A PLACE FOR MUSCLESTO ATTACH
Endoskeleton also includes theskull(protects brain as u see in mypicture), ribs(protects organs),arm and leg bones (help youmove)..but YOU already knewthat!
How can you tell the difference between types of vertebrates? BODY TEMPERATURE Fish, amphibians, reptiles are ECTOTHERMS - body temp. changes with environment.Birds and mammals are ENDOTHERMS- body controls temp by controllinginternal heat it produces.
One last fact about vertebrates: Chordates have slits in their throat called PHARYNGEAL Most other vertebrates have their PHARYNX pharyngeal slits disappear before birth.
PHARYNGEAL SLITSFish keep these slitsall their lives as partof their gills.
HOW DO FISH USE THEIR GILLS?WHAT ARE THE 3GROUPS OF FISH?
FISH:• vertebrates that live in water•fins for movement•ectothermic•gills to breathe•have scales - overlapping platesthat protect skin
OBTAINING O2 Fish swim along, open their mouth & take in H20 The H20 moves thru mouth to gillsGILLS: feather-like structures - redGILLSin color due to blood vessels in them.
H20 flows over gills O2 moves into blood C02 flows out into H20
Like all vertebrates, fish have a closedcirculatory system. The heart pumps blood in a loop:HEART GILLS BODY HEART
MOVEMENT FINS: thin membranestretched across bony supports
FEEDING FISH have highly developed nervous systems and sense organs to help incapturing food and avoiding predators Well, not like this…..more like….
Their eyesight is better than yours (remember there is less light under water) Sharks can smell and even taste a tiny amount of blood - as little as one drop- in 115 liters of water! That is 57.5 two liter sodas!
AND some fish have taste organs in the most unusual places. Catfishhave taste organs on their whiskers!
FEEDING Some fish like thebarracudahave sharp teeth for stabbing food
Others, like trout have short blunt teeth for gripping & crushing insects
Filter Feeders like the Basking Shark andManta Ray use comb-like structures ontheir gills to filter tiny plants and animalsfrom the water.
Fish Reproduction Most fish have external fertilization: as female releases eggs, malespreads a cloud of sperm over them. Some fish like guppies and sharks have internal fertilization: when the eggs are mature enough to live on their own, female gives birth.
Biologists classify fish into 3 groups: Jawless Fishes •Bony Fishes •Cartilaginous FishesThey are grouped according to their mouth structure and type of skeleton
Jawless Fish•No scales•skeletons made ofcartilage•one fin (no pairs offins)•jawless mouth Lampreys are eel shaped parasites-use sharp teethscrapes, stabs and and suction-cup mouth tosucks to get food feed
CARTILAGINOUS FISH Sharks, Rays, Skates•Skeletons made of cartilage•Have jaws and pairs of fins•Pointed, tooth-like scales cover bodies -rougher than sandpaper•Carnivores•Rays and Skates live on ocean floor - filterfeeders - east mollusks, crustaceans, smallfishes
CARTILAGINOUS FISH - Sharks•Streamlined bodies for quick movement•Mouth on bottom part of head•Jagged teeth arranged in rows - 1stcouple rows are for feeding - remainingrows are replacement teeth. If a tooth islost, one from next row moves up (NODENTURES EVER NEEDED!) Sharks
CARTILAGINOUS FISH - Sharks•Swimming or currents move waterover gills•Spend most of time hunting for food -will attack anything that smells likefood.•Poor eyesight - that is why theyswallow strange objects at times.
BONY FISH Most familiar fish are bony fish: trout, tuna, flounder, salmon, goldfish, etc.•Covered with scales•Pocket on each side of head thatholds gills - flap over gills opens torelease water
BONY FISH Swim Bladder and BuoyancyFish neither sink or float. They have anorgan called a SWIM BLADDER - sac thatstabilizes body at different depths. Itcontains O2, nitrogen & CO2...
Swim Bladder and Buoyancy...if the gas is less the fish sinks lower - if itis more the fish moves higher in the water. The change in the gas volume affects the Buoyancy Force - force that water exerts upward on any underwater object LESS THINK BALLOONS! MORE
Bony Fish Diversity•Make up 95% of all fish species • Live in salt and fresh water•Some live in deep water and some inshallow