Bio I ch8 Complex Animals

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Bio I ch-8 Complex Animals
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8-1 Complex Invertebrates

• Objectives
• Be able to identify the major traits of
  jointed-leg animals.
• Be able to compare insects with other jointed-leg
  animals.
• Be able to describe the traits of spiny-ski
  animals.

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8-1 Complex Invertebrates

• Vocabulary
• Jointed-leg animal
• Appendage
• Exoskeleton
• Molting
• Antennae
• Compound eye

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8-1 Complex Invertebrates

• Vocabulary
• Spiny-skin animal
• Tube feet

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8-1 Complex Invertebrates

• The animals in the two invertebrate phyla in this
  chapter are more complex than the animals you
  studied in Chapter 7. One phylum, containing
  insects and spiders, is familiar to everyone.
  Insects are found almost everywhere. It is hard
  to think of life without insects.

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8-1 Complex Invertebrates

• Jointed-leg Animals
• Have you ever watched an army of ants moving food
  back to its nest? Hundreds of these animals work
  together to carry food that is much larger than
  they are. Ants crawl along in single file,
  following a trail that they marked on
• the way to the food. Back in the nest, hungry
  ants wait for the hunters to return. Ants are
  amazing animals!

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8-1 Complex Invertebrates

• Ants are jointed-leg animals. A jointed-leg
  animal is an invertebrate with an outside
  skeleton, bilateral symmetry,
• and jointed appendages. An appendage is a
  structure that grows out of an animal's body.
  Jointed appendages bend to allow quick movement.
  Legs, antennae, and wings are all appendages.

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8-1 Complex Invertebrates

• The phylum of jointed-leg animals includes
  insects, spiders, and crayfish. It has more
  animal types than any other animal phylum. The
  graph on page 136 shows that over 80 percent, of
  the known animal types on Earth are jointed-leg
  animals.

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8-1 Complex Invertebrates

• Jointed-leg animals have a segmented body. In
  many of these animals, the segments are fused
  into three parts- the head, the thorax, and the
  abdomen. Look for these parts in the pictures in
  this section.

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8-1 Complex Invertebrates
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8-1 Complex Invertebrates

• Jointed-leg animals have an exoskeleton. An
  exoskeleton is a skeleton on the outside of the
  body. It is made of a hard, waterproof, nonliving
  substance. It protects the body from drying and
  injury, and provides a place for muscles to
  attach.
• How does an animal with an exoskeleton grow?

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8-1 Complex Invertebrates

• The animal must shed its exoskeleton from time to
  time. Shedding the exoskeleton is called molting.
  After the old skeleton is shed, the body is quite
  soft. The animal swells by taking in extra water
  or air while the new skeleton hardens. This
  swelling gives the animal growing room inside the
  new skeleton. The animal is not very well
  protected from its enemies, so it stays hidden
  until its skeleton hardens.

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8-1 Complex Invertebrates

• There are five classes of jointed-leg animals.
  Crayfish, shrimp, lobsters, crabs, water fleas,
  and pill bugs are in one class, Figure 8-2.
  Crayfish and water fleas are found in fresh
  water. Pill bugs live in damp places on land. The
  rest of these animals live in the ocean.

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8-1 Complex Invertebrates

• Figure 8-3 shows the traits of animals in the
  first class. Animals in this class have
  mouthparts that hold, cut, and crush food. They
  have two pairs of antennae. Antennae are
  appendages of the head that are used for sensing
  smell and touch. These animals also have compound
  eyes for seeing.

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8-1 Complex Invertebrates

• Compound eyes are eyes with many lenses. In
  contrast, you have simple eyes. They each have
  only one lens. , Most animals in this class have
  only two body sections.
• The head and the thorax are fused to make up one
  section. The abdomen is the second section. These
  animals usually have five pairs of legs for
  walking. A claw-like pair of legs at the head
  grabs and holds food.

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8-1 Complex Invertebrates

• The animals in this class are food for many fish
  and whales. Humans also eat lobsters, shrimp, and
  crabs.

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8-1 Complex Invertebrates
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8-1 Complex Invertebrates
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8-1 Complex Invertebrates

• The second class of jointed-leg animals includes
  spiders, scorpions, ticks, and harvestmen, also
  called daddy longlegs. Each has four pairs of
  walking legs, simple eyes, no antennae, and a
  body with two sections.

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8-1 Complex Invertebrates

• Spiders feed on insects. Most spiders trap
  insects in webs. The head of a spider has a pair
  of hollow fangs that connect to poison glands.
  When a spider traps an insect and bites into it,
  the poison stuns the insect. You may think that
  all spiders are dangerous to people. However,
  only a few spiders, like the black widow, have
  poison that causes serious sickness in people.

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8-1 Complex Invertebrates

• Scorpions have a pointed stinger on the end of
  their abdomen. The stinger contains poison.
  Scorpions use their stinger for protection
  against enemies, but they can harm people, too.

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8-1 Complex Invertebrates

• The third and fourth classes of jointed-leg
  animals include the centipedes and millipedes.
  Centipedes and millipedes live on land under
  rocks or wood. They both have heads, long
  segmented bodies, and many legs.

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8-1 Complex Invertebrates

• The name centipede suggests that these animals
  have one hundred legs. Remember that centi- means
  100. Pede means foot. Actually centipedes usually
  have no more than 30 legs.

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8-1 Complex Invertebrates

• You can see in Figure 8-5 that each of their
  segments has one pair of walking legs. The
  appendages on the first segment are poison claws.
  They help capture food. Centipedes usually eat
  insects.

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8-1 Complex Invertebrates

• Millipedes are slow-moving animals. They have two
  pairs of legs on most segments. They do not
  really have a thousand legs, as the name has you
  believe. Millipedes do not have poison claws.
  They usually eat decaying plants.

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8-1 Complex Invertebrates

• Insects are the fifth class of jointed-leg
  animals. There are more kinds of insects than all
  other animals combined. They live almost
  everywhere. They live deep in the ocean and high
  on mountain tops. They live in the air and on the
  ground, in the tropics and even at the North and
  South poles.

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8-1 Complex Invertebrates

• They come in many shapes and colors. They can eat
  almost anything because they have special
  mouthparts for , chewing, sucking, or lapping.

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8-1 Complex Invertebrates

• How can you tell if an organism is an insect? An
  insect's body has three main parts as shown in
  Figure 8-6. The
• head has two compound eyes and usually three
  simple eyes, one pair of antennae, and several
  mouthparts. The thorax has three pairs of walking
  legs and usually two pairs of wings, so the
  animal can fly. Insects are the only
  invertebrates that can fly.

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8-1 Complex Invertebrates

• Insects reproduce sexually, with separate sexes
  producing eggs and sperm. The fertilized eggs are
  laid in .' large numbers on leaves or branches of
  plants.

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8-1 Complex Invertebrates

• Insects can be helpful or harmful. Some insects
  destroy food crops. For example, Mediterranean
  fruit flies can destroy all of the fruit in an
  orchard. Moths can eat holes in your clothing
  when they feed on oils in the fabric or food
  particles you have left there. Termites destroy
  wood in buildings and fences. Why do people try
  to prevent houseflies from touching food?
  Houseflies carry bacteria that cause diseases.

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8-1 Complex Invertebrates

• Some insects help farmers by eating harmful
  insects. Ladybird beetles, or ladybugs, eat
  aphids that feed on
• many types of plants. Bees and other insects
  carry pollen from flower to flower. Crops must be
  pollinated in order to reproduce. There are
  insects that produce food and other useful
  materials. Honeybees, for example, produce honey.

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8-1 Complex Invertebrates
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8-1 Complex Invertebrates
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8-1 Complex Invertebrates

• Spiny-skin Animals
• The animal in Figure 8-7a looks like a living
  pincushion. It is a sea urchin. The sea urchin,
  starfish, and sand dollar belong to the phylum of
  spiny-skin animals. A spiny-skin animal is an
  invertebrate with a five-part body design, radial
  symmetry, and spines.

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8-1 Complex Invertebrates

• Count the arms of the starfish in Figure 8-7b.
  Sand dollars and sea urchins also show the
  five-part body design. You may have walked along
  a beach and seen these animals. They are found
  only in the oceans. They are very common on rocky
  shores.

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8-1 Complex Invertebrates

• What are some other traits of spiny-skin animals?
  If you look closely at the bottom of a starfish
  you will see dozens of tube feet, like those in
  Figure 8-8. Tube feet are parts like suction cups
  that help the starfish move, attach to rocks, and
  get food. If you ever try to pull a starfish from
  a rock, you will see how tightly it holds onto
  the rock with its tube feet. A tube foot works
  like a medicine dropper.

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8-1 Complex Invertebrates

• If you squeeze the bulb of a dropper filled with
  water, you force out the water. If you squeeze
  the bulb and then place your finger against the
  open end, you will feel suction when you let go
  of the bulb. A starfish grips slippery rocks in
  much the same way. The starfish takes in ocean
  water and passes it through a series of canals to
  the tube feet. As this water moves in and out of
  the tube feet, suction is made and released.

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8-1 Complex Invertebrates
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8-1 Complex Invertebrates

• If a starfish loses an arm it can grow a new one,
  as s in Figure 8-9. A whole new animal can grow
  from one arm if the arm is still attached to part
  of the central body. This is a form of asexual
  reproduction. Starfish also reproduce sexually
  with separate sexes producing eggs and sperm.

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8-1 Complex Invertebrates
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8-2 Vertebrates

• Objectives
• Be able to compare the traits of jawless fish,
  cartilage fish, and bony fish.
• Be able to describe the major traits of
  amphibians, reptiles, and birds.
• Be able to identify the characteristics of
  mammals.

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8-2 Vertebrates

• Vocabulary
• Chordate
• Endoskeleton
• Cold-blooded
• Gill
• Jawless fish
• cartilage

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8-2 Vertebrates

• Vocabulary
• Cartilage fish Mammal
• Bony fish Mammary gland
• Amphibian
• Hibernation
• Reptile
• Warm-blooded

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8-2 Vertebrates

• You have been learning about some of the phyla
  that make up the invertebrate animals, those with
  no backbone. Animals that have a backbone are
  called vertebrates. All vertebrates belong to the
  chordate phylum. Vertebrates are the most complex
  organisms in the animal kingdom.

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8-2 Vertebrates

• Chordates
• The chordate phylum is probably the most familiar
  to you. The structures and ways of life of these
  animals are most like yours. They are your food,
  your pets, farm animals, the animals you see all
  around you. Chordates live in water as well as
  on land.

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8-2 Vertebrates

• Some chordates, such as bats and birds, are able
  to fly. You, too, belong to this phylum. How do
  you identify a chordate? A chordate is an animal
  that, at some time in its life, has a tough,
  flexible rod along its back. The chordate phylum
  is named for this trait.

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8-2 Vertebrates

• The chordate phylum contains the largest animals
  on Earth, one of which is shown in Figure 8-10.
  How are chordates able to grow so large? They
  have an endoskeleton . An endoskeleton is a
  skeleton on the inside of the body. An
  exoskeleton limits growth because it is on the
  outside of the body. Animals with endoskeletons
  don't have this problem.

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8-2 Vertebrates
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8-2 Vertebrates
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8-2 Vertebrates

• Vertebrates are chordates. In most vertebrates,
  the rod along the back is replaced by a backbone.
  Vertebrates have well developed body systems.
  They have a circulatory system with a heart and
  blood vessels, a digestive system to change food
  into a useful form, a skeletal system for
  support, a respiratory system for gas exchange,
  and a nervous system for control.

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8-2 Vertebrates

• Vertebrates have large brains, well-developed
  senses, and are very intelligent animals.
• The seven vertebrate classes are jawless fish,
  cartilage fish, bony fish, amphibians, reptiles,
  birds, and mammals.

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8-2 Vertebrates

• Characteristics of Fish
• Three of the seven vertebrate classes are fish.
  All fish have certain traits in common. Fish are
  cold-blooded vertebrates that live in water and
  breathe with gills. Cold-blooded means having a
  body temperature that changes with the
  temperature of the surroundings. Fish have gills
  on each side of the throat region. A gill is a
  structure used to breathe in water.

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8-2 Vertebrates

• The fish pumps water into its mouth and out
  through the gills, Figure 8-11. The gills pick up
  oxygen from the water as it passes through.

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8-2 Vertebrates

• Most fish have scales that cover and protect
  their bodies. They also have fins that help them
  swim. The fins steer the fish as it moves its
  body from side to side through, the water. A
  lateral line runs along each side of the body.
  The lateral line is an important sense organ for
  fish because it detects water movement and the
  presence of objects.

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8-2 Vertebrates

• There are three different classes of fish in the
  chordate phylum. They are jawless fish, cartilage
  fish, and bony fish

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8-2 Vertebrates
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8-2 Vertebrates

• Jawless Fish
• Jawless fish are fish that have no jaws and are
  not covered with scales. The skeletons of jawless
  fish are made of cartilage. Cartilage is a tough,
  flexible tissue that supports and shapes the
  body. Your ears and nose tip are made up of
  cartilage.
• The lamprey shown in Figure 8-12 is a jawless
  fish. Lampreys have tube-like bodies covered with
  slime that protects the skin. They don't have
  paired fins. Lampreys swim by waving their body
  from side to side.

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8-2 Vertebrates

• The lamprey shown in Figure 8-12 is a jawless
  fish. Lampreys have tube-like bodies covered with
  slime that protects the skin. They don't have
  paired fins. Lampreys swim by waving their body
  from side to side.

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8-2 Vertebrates

• The lamprey's mouth does not have jaws. It is a
  round opening lined with tooth-like structures.
  How does the lamprey eat? Many lampreys attach
  themselves to the sides of other fish with their
  sharp, tooth-like structures. The lamprey cuts a
  hole through the skin and sucks out the blood and
  body fluids. Are lampreys parasites?

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8-2 Vertebrates
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8-2 Vertebrates

• Sharks have slim bodies and paired fins that help
  with, movement and balance. Sharks are fast
  swimmers.
• Rows of sharp teeth that slant backward cover the
  shark's jaws. The teeth help sharks hold and cut
  up their food. l\'1ost sharks eat other animals
  that live in the ocean. However, the whale shark
  eats only protists.

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8-2 Vertebrates

• Rays are flat and live on the ocean bottom,
  Figure 8-14. They eat fish and invertebrates in
  the ocean. Most rays are harmless to humans, but
  some stingrays have whip-like tails with stingers
  that can cause a painful wound.

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8-2 Vertebrates

• Bony Fish
• Most fish known today belong to the class of bony
  fish. Bony fish have skeletons made mostly of
  bone, not of cartilage. Many fish that you eat,
  such as perch, bass, flounder, and trout, are in
  this group. You may have seen some of these fish
  in a supermarket.

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8-2 Vertebrates

• Figure 8-16 shows the important traits of bony
  fish. Most bony fish have smooth, bony scales
  that are covered with a slimy coating, but some,
  like the catfish in Figure 8-15, have
  slime-covered leathery skin instead. The slime
  and scales protect the fish from infections and
  from enemies.

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8-2 Vertebrates

• The slime also makes it easier for the fish to
  glide through the water .
• Bony fish have a flap that covers and protects
  the gills. Jawless fish and cartilage fish do not
  have this flap. Most bony fish have a swim
  bladder. A swim bladder is a baglike structure
  that fills with gases and helps the fish float
  and go up and down in the water.

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8-2 Vertebrates

• Fish can change the amount of gas in the swim
  bladder. As the bladder fills with gas, the fish
  rises. As the gas is let out, the fish goes
  deeper .

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8-2 Vertebrates

• Most fish need water to reproduce. The female
  lays large numbers of eggs in the water. The male
  fish deposits sperm in the water, and some of the
  eggs are fertilized when the sperm swim to the
  eggs.

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8-2 Vertebrates
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8-2 Vertebrates

• Amphibians
• Amphibians include frogs, toads, and salamanders.
  An amphibian is an animal that lives part of its
  life in water and another part of its life on
  land. Usually, young amphibians live in water and
  adult amphibians live mostly on land. Amphibians
  that live mostly on land still need water.
  Without water, an amphibian's skin dries out.
  Amphibian eggs are laid in water so they won't
  dry out.

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8-2 Vertebrates

• The female lays large numbers of eggs. The male
  deposits sperm in the water. Only a few eggs are
  fertilized.
• Amphibian young look very different from the
  adults.

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8-2 Vertebrates

• Notice that the tadpole in Figure 8-17b is
  different from an adult frog in many ways.
  Tadpoles must live in water and breathe with
  gills. The adults have lungs and can take in
  oxygen from the air. They also take in oxygen
  through their moist skins and the linings of
  their mouths.

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8-2 Vertebrates

• Frogs and toads are probably familiar to you.
  Figure 8-17a shows some of their traits. Most
  frogs and toads do not have tails. They have
  broad mouths with long, sticky tongues for
  catching insects. They have two pairs of legs.
  The hind legs are much larger and more powerful
  than the front legs, so the animal can jump great
  distances.

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8-2 Vertebrates

• Frogs and toads have webbed feet for swimming.
  Their eyes stick out from their heads. This trait
  allows them to hide under the water with only
  their eyes showing above the surface. When an
  insect flies by, the frog flicks out its sticky
  tongue and catches the insect.

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8-2 Vertebrates
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8-2 Vertebrates

• Salamanders are amphibians with a tail. Their two
  pairs of legs are about the same size, Figure
  8-18,a. They live only in moist places. Some
  salamanders keep their gills throughout their
  lives and live in water, even as adults.
  Amphibians are cold-blooded vertebrates. Their
  body temperature drops as the temperature of their

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8-2 Vertebrates

• surroundings drops. Because they are
  cold-blooded, amphibians become inactive during
  cold weather. The state of being inactive during
  cold weather is called hibernation. Animals that
  hibernate eat no food and use only a little
  oxygen. Their energy needs are met with stored
  fat.

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8-2 Vertebrates

• Amphibians help control insects. Amphibians also
  are used in life science studies and in medical
  research. They are eaten by snakes, turtles,
  birds, and mammals.

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8-2 Vertebrates

• Reptiles
• You may have seen a snake at one time and thought
  it looked slimy. If you touched the snake, you
  probably were surprised to find that it was not
  slimy at all. Snakes are reptiles. A reptile is
  an animal that has dry, scaly skin and can live
  on land. Reptiles were the first vertebrates to
  live and reproduce entirely on land. Snakes,
  lizards, turtles, crocodiles, and alligators are
  all reptiles.

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8-2 Vertebrates

• What are the traits of reptiles? Look at Figure
  8-19. Reptiles are cold-blooded vertebrates with
  a backbone and an endoskeleton. Their scaly skin
  protects them, prevents water loss, and keeps
  them from drying out. Some reptiles are covered
  by hard plates instead of scales. They have
  well-developed lungs for breathing air. Most
  reptiles have two pairs of legs and clawed toes,
  but snakes and some lizards don't have legs. Most
  reptiles can move quickly.

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8-2 Vertebrates

• They use their claws for running and climbing,
  and for digging nests in the soil. A reptile egg
  has a tough,
• leathery shell that protects it and keeps it from
  drying out. Because reptile eggs have shells,
  they can be laid on land instead of in the water.
  Even though reptiles do not need to live in
  water, many still do.

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8-2 Vertebrates

• Alligators, crocodiles, and turtles, for example,
  spend a good part of their lives in or near the
  water.
• Reptiles eat insects and pests such as rats and
  mice. In some areas of the world, people eat
  reptiles and their eggs.

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• Birds
• Birds are vertebrates that have wings, a beak,
  two legs, and a covering of feathers over most of
  their bodies. Some of the traits of birds are
  shown in Figure 8-20. Like reptiles, birds have
  scales, but the scales are only on their legs.
  Birds also have claws on their toes. They have
  well-developed lungs. Female birds, like
  reptiles, lay eggs with shells from which the
  young develop.

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8-2 Vertebrates

• Most birds are well adapted for flying. They have
  hollow bones, which makes them light in weight.
  Birds have powerful muscles to move their wings.
  Some birds, such as the ostrich, do not fly.
  Ostriches, however, can run as fast as 48 km an
  hour, about the speed of a racing bike.

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• Birds are warm-blooded. Warm-blooded means
  controlling the body temperature so that it stays
  about the same no matter what the temperature of
  the surroundings. Feathers help the body keep a
  constant body temperature.

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• Birds have no teeth. Instead, they have beaks
  that they use to get food. The kind of beak .a
  bird has is related to
• the kind of food it eats. Figure 8-21 shows some
  examples. Woodpeckers have beaks that cut through
  tree bark to expose insects. Sparrows and
  cardinals have thick beaks that crack seeds.
  Hawks have sharp beaks that tear meat.

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8-2 Vertebrates

• Birds are important to us in many ways. They help
  farmers by eating insects and the seeds of weeds.
  Some birds eat rats and mice. Chickens and ducks
  provide eggs and meat. Some people have birds as
  pets. Many people enjoy watching and feeding wild
  birds. The bald eagle is the national bird in the
  United States. Do you know the state bird for
  your state ?

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8-2 Vertebrates

• Mammals
• What traits are found in the animals in Figure
  8-22? First, they have hair and are warm-blooded.
  The hair helps keep a constant body temperature.
  Second, the females have milk glands with which
  they nurse their young. These animals are
  mammals. A mammal is an animal that has hair and
  feeds milk to its young. You are a mammal.

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8-2 Vertebrates

• Most animals that you have studied hatch from
  eggs. Mammals usually develop inside the mother's
  body and are born alive. After birth, young
  mammals feed on milk produced by the mother's
  mammary glands. Mammary glands are body parts
  that produce milk.

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• Male mammals also have mammary glands, but they
  don't produce milk. Besides providing milk, all
  mammals care for their young.

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• Two groups of mammals whose young do not develop
  inside the mother's body are the pouched mammals
  and the egg-laying mammals. Kangaroos and
  opossums are pouched mammals. The young of
  kangaroos and opossums are not fully developed at
  birth. After birth, they crawl into a pouch
  outside the mother's body.

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• There they attach themselves to the mother's
  mammary glands and feed on milk until they are
  more fully developed. Egg-laying mammals, such as
  the duck-billed platypus shown in Figure 8-23b,
  lay eggs like those of reptiles.

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8-2 Vertebrates

• Now that you have studied the entire animal
  kingdom, let's see where you fit, in. Remember
  that you are also a chordate and a mammal. You
  can see the smaller subgroups in Table 8-1. The
  name of your genus is Homo. Your species name is
  sapiens. These names make up the scientific name
  of humans, Homo sapiens. The Latin word Homo
  means man and sapiens means wise. Together Homo
  sapiens means wise man.

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