Fishes - walker2012
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Transcript Fishes - walker2012
Fishes
Section 30.1
Animal Classification
Invertebrates
Sponges
Cnidarians
Worms
Mollusks
Arthropods
Echinoderms
Animals
Ectotherms
(cold-blooded)
Vertebrates
Fishes
Amphibians
Reptiles
Phylum Chordata
Endotherms
(warm-blooded)
Birds
Mammals
Classes of Fishes
Superclass Agnatha – jawless fish
Hagfish feed on dead or dying fishes
Lampreys use suckerlike mouths to suck out the
prey’s blood
Skeleton made of cartilage
Classes of Fishes
Classes of Fishes
Class Chondrichthyes (kahn DRIHK the ez)
Cartilaginous fishes
Sharks, skates and rays
Classes of Fishes
Class Osteichthyes (ahs tee IHK the ez)
Bony fishes
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
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
Two-Chambered Hearts
Atrium – receiving chamber of the heart
Ventricle – pumping chamber of the heart
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
Paired Fins
Fishes in the class Chondrichthyes and
Ostheichthyes have paired fins
Fins – fan-shaped membranes that are used
for balance, swimming, and steering
Paired Fins
Dorsal – towards the
backbone
Pectoral – chest area
Pelvic – hip area
Anal
Caudal - tail
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
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)
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
Scales
Scales – thin bony plates formed from the
skin
Scales can be toothlike, diamond-shaped,
cone-shaped, or round
Scales
Shark scales are similar to teeth found in
other vertebrates
Jaws
The advantage of jaws is that they enable an
animal to grasp and crush its prey with great
force
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
Vertebrae Provides Flexibility
Separate vertebrae are important for fish
locomotion which involves continuous flexing
of the backbone
Swim Bladder
Swim bladder – a thin-walled, internal sac
found just below the backbone in most bony
fishes
A swim bladder controls a fish’s depth by
regulating the amount of gas in the bladder
Swim Bladder
Some fishes remove gases through a special
duct that attaches the swim bladder to the
esophagus
Sharks don’t have swim bladders
Sharks maintain their buoyancy via fatty livers