Download Chapter 14 Notes

Chapter # 14 Notes
Fish, Amphibians and Reptiles
Sec. # 14-1 Chordates and Vertebrates
Chordate Characteristics:
Chordate – animals with four characteristics present at some stage in development; notochord, postanal
tail, nerve cord, pharyngeal pouches.
Notocord – supports the animal and extends along the upper part of the body
 The notochord is flexible but firm because it is made up of fluid-filled cells that are enclosed in a
stiff covering.
 The notochord also extends into a postanal tail
Postanal Tail – muscular structure at the end of a developing chordate
 Some chordates, such as fish, Amphibians, reptiles and mammals, develop a backbone that
partially or entirely replace the notochord
 In some chordates the notochord is kept into adulthood
Nerve Cord- tube like structure above the notochord that develops into the brain and spinal cord
 becomes the central nervous system
Pharyngeal Pouches- paired openings found between the mouth and digestive tube in the developing
chordate
Vertebrate Characteristics:
There are traits that set vertebrates apart from other chordates.
Structure
1) Endoskeleton – supportive framework of bone and/or cartilage that provides an internal place
for muscle attachment and protects a vertebrate’s internal organ.
Cartilage- tough, flexible tissue that joins vertebrae and makes up all or part of the vertebrate
endoskeleton. (Ears, end of nose)
2) Vertebrae – backbones that are joined by flexible cartilage and protect a vertebrate’s spinal cord
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Most vertebrates have a head, with a skull that encloses and protects the brain
Most of the vertebrate’s internal organs are found in the central cavity.
Have a protective skin
Hair, feathers, scales, or horns sometimes grows from the skin
Vertebrate Groups:
 Seven main groups of vertebrates are found on Earth (Jawless fish, Jawed cartilaginous fish,
Bony fish, Amphibians, Reptiles, Birds, Mammals)
 Vertebrates are either ectotherms or endotherms
Ectotherm – organisms that has an internal body temperature that changes with the surroundings
(fish, amphibian’s reptiles)
Endotherm – an organism that has a nearly constant internal temperature. (mammals, birds)
Vertebrate Origins
 some vertebrate fossils date back 420 million years ago (mya)
 Lobe finned fish = 395 mya
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Amphibians = 350 mya
Reptiles = 350 mya
Dinosaurs = 230 mya
Archaeopteryx (ancestor of birds) = 150 mya
Mammal-like reptiles = 235 mya
True mammals = 38 mya
Sec. 14-2 Fish
Fish Characteristics:
 There are more species of fish than species of other vertebrate group.
 All fish are ectotherms
 They have adapted for living in nearly every type of water environment from shallow pools to
deep oceans.
 Streamlined shape
 Muscular tail & fins allow fish to move in the water
Fins- fanlike structure attached to the endoskeleton
 most fish secrete a slimy mucus that helps them move through water
 most fish have scales
Scales – hard, thin plates that cover and protect the body
Body Systems:
 All fish have highly developed sensory systems
 Most fish have a lateral line system
Lateral line System – made up of structures that extend along the length of a fishes body. Enable a
fish to sense its surroundings and detect movement.
 two chambered heart
 Most fish have gills
Gills – organs for exchange of gas
 fish have many feeding adaptations
 Reproduce sexually by external fertilization. Females releases eggs into the water the male then
swim over the eggs and release sperm (spawning)
 some species of sharks and Rays have internal fertilization and lay fertilized eggs
 Even a few fish such as guppies have internal fertilization but the eggs develop and hatch inside
the female body. After they hatch they leave her body
Types of Fish:
 fish vary in size, color, living environment and other factors.
Fish are grouped into 3 categories:
1) Jawless Fish
2) Jawed Cartilaginous fish
3) Bony Fish
Jawless: (Lampreys, hagfish)
 round toothed mouth
 tube like bodies covered with slimy skin and no scales
 most are parasites
 flexible endoskeleton
Jawed Cartilaginous Fish: (sharks, skates & rays)
 endoskeleton made of cartilage
 movable jaws
 well developed teeth
 tiny scale cover their body
 top predators in many ecosystems
 Oily liver for flotation
Bony Fish: (perch, catfish, bass, etc.)
 skeletons made of bone
 bony flap that covers and protects the gills
 Have a swim bladder
Swim bladder - Air sac that allows fish to adjust to the density of the surrounding water so that it
will not sink or float to the surface
The Three Types of Bony Fish:
1) Lobe Finned Fish (coelacanths)
 Thought to be extinct but were rediscovered in 1938
 Scientists think fish similar to Coelacanths were the ancestors of the first land vertebrates the
amphibians
2) Lungfish
 can breathe air when needed
3) Ray-finned Fish
 fins made of long thin bones covered with skin
 most bony fish are ray-finned
 variation in body plans
Sec. 14-3 Amphibians
Amphibian Characteristics:
 Amphibian means “double life”
 Salamanders, toads, frogs, newts
 Spend part of their life on land and part of their life in the water
 Ectotherms
 Use special techniques to stay alive in cold or hot weather called Hibernation and Estivation
Hibernation – inactivity during cold weather
Estivation – Inactivity during hot, dry months
 have moist, smooth, thin skin without scales
 Breathe through their skin and most also have simple, small lungs
 3 chambered heart
 Eggs have no protective, waterproof shell so they can dry out easily. They must have water to
reproduce.
 External Fertilization
 Most amphibians go through metamorphosis (egg-larva/tadpole- adult)
Frogs & Toads:
 short broad bodies with 4 legs but no neck or tail
 hind legs are for swimming and jumping
 Bulging eyes and nostrils on top of the head
 Tympanic membranes for hearing
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Tongues attached to the front
Eat insects, worms, fish, spiders, crustaceans, etc.
Toads are dryer and bumpier than frogs.
Toad generally walk while frogs hop
Salamanders:
 Long slender body
 Short legs
 Found near water
 Feed on worms, crustaceans, insects
 Breed on land using internal fertilization
More Amphibian Facts:
 Most adult amphibians are insect eaters
 Poison dart frogs can fill large animals with their poison
 Amphibians are effected directly by pesticides and pollution because they absorb gases and
water through their skin. (environmental indicators)
Sec. 14-4 Reptiles
Reptile Characteristics:
 reptiles have thick, dry waterproof skin
 skin is covered with scales
 ectotherms
 Snakes, turtles, tortoises, lizards, crocodiles and alligators
 Breathe with lungs
 Circulation system is more developed than the amphibians
 3 chambered heart except crocodiles which have 4 chambers
 Have an Amniotic Egg
Amniotic Egg- - egg covered with a shell that provides a complete environment for the embryo’s
development. For reptiles it was a major adaptation for living on land
 Internal Fertilization
 Eggs laid on land.
Lizards and Snakes:
 largest group of Reptiles
 have special jaw that has a joint that unhinges and increases the size of their mouths
 swallow prey whole
Lizards moveable eyelids
 external ears
 legs with clawed toes
 feed on plants, other reptiles, insects, spiders, worms and mammals
Snakes developed ways to move without legs
 poor hearing
 poor eyesight
 the “hear” vibrations in the ground by picking up the vibrations by the lower jawbone and
conducted to bones of the inner ear
 carnivores
 some are constrictors
 some inject their prey with venom
 Internal Fertilization
 Lay eggs with a hard shell
Turtles only reptiles that have a two part shell made of hard, bony plates
 vertebrae and ribs are fused to the inside of the top shell
 can withdraw head and legs into shell
 no teeth
 powerful jaws
 eat insects, worms, fish, and plants
 Some turtles live in water and some live on land.
 Turtles that live on land are called tortoises
 Lay hard shelled eggs
Crocodilians crocodiles, alligators
 found on or near water in warm climates
 Crocodiles have a narrow head with a triangular shaped snout
 Alligators have a broad head with a rounded snout
 Care for their young
Importance of Reptiles:
 snakes eat mice and rats
 lizards eat insects
 large lizrds eat small animals that are considered pests
Reptiles appeared about 345 mya
Chapter # 14 Vocabulary
Sec. 14-1
Chordate – animals with four characteristics present at some stage in development; notochord, postanal
tail, nerve cord, pharyngeal pouches.
Notocord – supports the animal and extends along the upper part of the body
Pharyngeal Pouches- paired openings found between the mouth and digestive tube in the developing
chordate
Endoskeleton – supportive framework of bone and/or cartilage that provides an internal place for
muscle attachment and protects a vertebrate’s internal organ.
Cartilage- tough, flexible tissue that joins vertebrae and makes up all or part of the vertebrate
endoskeleton. (Ears, end of nose)
Vertebrae – backbones that are joined by flexible cartilage and protect a vertebrate’s spinal cord
Ectotherm – organisms that has an internal body temperature that changes with the surroundings (fish,
amphibian’s reptiles)
Endotherm – an organism that has a nearly constant internal temperature. (mammals, birds)
Sec. 14-2
Fins- fanlike structure attached to the endoskeleton
Scales – hard, thin plates that cover and protect the body
Lateral line System – made up of structures that extend along the length of a fishes body. Enable a fish
to sense its surroundings and detect movement
Gills – organs for exchange of gas
Swim bladder - Air sac that allows fish to adjust to the density of the surrounding water so that it will
not sink or float to the surface
Sec. 14-3
Hibernation – inactivity during cold weather
Estivation – Inactivity during hot, dry months
Sec. 14-4
Amniotic Egg- - egg covered with a shell that provides a complete environment for the embryo’s
development. For reptiles it was a major adaptation for living on land