Muscular System

1
Fishes
Section 30.1
2
Animal Classification
Sponges Cnidarians Worms Mollusks Arthropods Echin
oderms
Invertebrates
Animals
Amphibians Reptiles
Fishes
Ectotherms (cold-blooded)
Vertebrates
Phylum Chordata
Birds Mammals
Endotherms (warm-blooded)
3
Classes of Fishes

• Superclass Agnatha jawless fish
• Hagfish feed on dead or dying fishes
• Lampreys use suckerlike mouths to suck out the
  preys blood
• Skeleton made of cartilage

4
Classes of Fishes
5
Classes of Fishes

• Class Chondrichthyes (kahn DRIHK the ez)
• Cartilaginous fishes
• Sharks, skates and rays

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Classes of Fishes

• Class Osteichthyes (ahs tee IHK the ez)
• Bony fishes

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Fishes Breathe Using Gills

• Fishes have gills made up of feathery gill
  filaments that contain tiny blood vessels
• Oxygen and carbon dioxide are exchanged through
  the capillaries in the gill filaments

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Two-Chambered Hearts

• One chamber receives deoxygenated blood from the
  body tissues, and the second chamber pumps blood
  directly to the capillaries of the gills

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Two-Chambered Hearts

• Atrium receiving chamber of the heart
• Ventricle pumping chamber of the heart

10
Sexual Reproduction

• External fertilization is common in most fishes
• Spawning External fertilization in fishes
• Cod can produce as many as 9 million eggs, of
  which only a small percentage survive
• No parental involvement after spawning
• Cartilaginous fishes undergo internal
  fertilization

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Paired Fins

• Fishes in the class Chondrichthyes and
  Ostheichthyes have paired fins
• Fins fan-shaped membranes that are used for
  balance, swimming, and steering

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Paired Fins

• Dorsal towards the backbone
• Pectoral chest area
• Pelvic hip area
• Anal
• Caudal - tail

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Developed Sensory Systems

• Lateral line system a line of fluid-filled
  canals running along the sides of a fish that
  enable it to detect movement and vibrations in
  the water
• Found in cartilaginous and bony fishes

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Developed Sensory Systems

• Fishes have eyes
• Some fishes that live areas absent of light may
  have reduced, almost non-functional eyes

Blind cave fish (small, non-functioning eyes)
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Developed Sensory Systems

• Some fishes have an extremely sensitive sense of
  smell
• Sharks can follow a trail of blood through the
  water for 300 feet

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Scales

• Scales thin bony plates formed from the skin
• Scales can be toothlike, diamond-shaped,
  cone-shaped, or round

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Scales

• Shark scales are similar to teeth found in other
  vertebrates

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Jaws

• The advantage of jaws is that they enable an
  animal to grasp and crush its prey with great
  force

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Jaws

• Sharks have up to 20 rows of teeth that are
  continually replaced (e.g. vending machine)
• Their teeth point backwards to prevent prey from
  escaping once caught

20
Vertebrae Provides Flexibility

• Separate vertebrae are important for fish
  locomotion which involves continuous flexing of
  the backbone

21
Swim Bladder

• Swim bladder a thin-walled, internal sac found
  just below the backbone in most bony fishes
• A swim bladder controls a fishs depth by
  regulating the amount of gas in the bladder

22
Swim Bladder

• Some fishes remove gases through a special duct
  that attaches the swim bladder to the esophagus
• Sharks dont have swim bladders
• Sharks maintain their buoyancy via fatty livers