EVERYTHING YOU ALWAYS WANTED TO KNOW ABOUT:. INVERTEBRATES. WHAT MAIN CHARACTERISTIC IS SHARED BY ALL VERTEBRATES?. IF YOU SAID BACKBONE, YOU ARE CORRECT!. VERTEBRATES ARE MEMBERS OF THE PHYLUM CHORDATO - (from the name notochord )also called Chordates. CHORDATE Characteristics:.
BY ALL VERTEBRATES?
VERTEBRATES ARE MEMBERS OF THE PHYLUM CHORDATO - (from the name notochord)also called Chordates
At some time in life they have: NOTOCHORD, or nerve cord - a rod like structure that supports back.
Your NOTOCHORD is your spinal cord - It’s the connection between the brain and the nerves
SOME VERTEBRATES have backbone made of CARTILAGE (connective tissue - softer than bone but still strong!
EACH VERTEBRAE HAS A HOLE IN IT THAT THE SPINAL CORD GOES THRU - like fingers fit into rings
The backbone is part of the ENDOSKELETON (internal skeleton). It’s job:
Endoskeleton also includes the skull(protects brain as u see in my picture), ribs(protects organs), arm and leg bones (help you move)..but YOU already knew that!
How can you tell the difference between types of vertebrates?
Fish, amphibians, reptiles are ECTOTHERMS - body temp. changes with environment.
Birds and mammals are ENDOTHERMS - body controls temp by controlling internal heat it produces.
Chordates have slits in their throat called PHARYNGEAL
Most other vertebrates have their pharyngeal slits disappear before birth.
Fish keep these slits all their lives as part of their gills.
WHAT ARE THE 3 GROUPS OF FISH?
Fish swim along, open their mouth & take in H20
The H20 moves thru mouth to gills
GILLS: feather-like structures - red in 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 closed circulatory system. The heart pumps blood in a loop:
HEART GILLS BODY HEART
FINS:thin membrane stretched across bony supports
FISH have highly developed nervous systems and sense organs to help in capturing 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. Catfish have taste organs on their whiskers!
Some fish like the barracuda have sharp teeth for stabbing food
Others, like trout have short blunt teeth for gripping & crushing insects
Filter Feeders like the Basking Shark and Manta Ray use comb-like structures on their gills to filter tiny plants and animals from the water.
Most fish have external fertilization: as female releases eggs, male spreads 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.
They are grouped according to their mouth structure and type of skeleton
Lampreys are eel shaped parasites-use sharp teeth and suction-cup mouth to feed
Sharks, Rays, Skates
Most familiar fish are bony fish: trout, tuna, flounder, salmon, goldfish, etc.
Swim Bladder and Buoyancy
Fish neither sink or float. They have an organ called a SWIM BLADDER - sac that stabilizes body at different depths. It contains O2, nitrogen & CO2...
...if the gas is less the fish sinks lower - if it is 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