Download Fishes

 Learning
Goal
• Name the main characteristics of fishes
• Name the major groups of fishes and describe how
they differ
 Warm
up:
• What does the backbone surround and protect in a
vertebrate?
Homework:
• Finish pages 5-8
Chapter 11 Section 2
 Vertebrate
 Lives
in the water
 Uses fins to move
 Ectotherms
 Obtain oxygen through gills
 Have scales
 Fishes
get oxygen from the water
• Fish gulps water (water contains oxygen)
• Moves through openings in fish’s throat to the
gills
• Water flows over gills
• Oxygen moves from water into the fish’s blood
• Carbon dioxide comes out through gill covers
(operculae)
 Closed
circulatory
system
 Heart has two
chambers, or inner
spaces
• Pumps blood in one loop
 Heart to the gills
 Gills to rest of the body
 Back to heart
 Fins
help fish swim
 Thin membrane
stretched across bony
supports, rays
 Fin provides large
surface to push against
the water (canoe paddle)
 Movement is related to
obtaining food and
reproduction
 External
fertilization: the eggs are
fertilized outside the female’s body
 Male hovers close to female and
spreads a cloud of sperm cells over
the eggs
 Internal
fertilization: giving birth to
live young
• Sharks
• Guppies
 Nervous
system and sense organs of fishes
help them find food and avoid predators
 Keen sense of touch, smell, and taste help
fishes capture food
Jawless
Cartilaginous
Bony
 No
jaws or scales
 Have mouths instead (scraping, stabbing,
and sucking their food)
 Cartilage: tissue that is more flexible than
bone
 Examples
• Hagfish
 Look like large, slimy worms
• Lampreys
 Can be parasites
 Use sharp teeth and suction cup mouths to feed on other
fishes
 Eel-shaped bodies



Have jaws and scales, and
skeletons made of cartilage
Most sharks cannot pump water
over their gills, rely on swimming
or currents to keep water moving
across gills
Rays and skate take in water
through small holes located
behind their eyes
 Usually carnivores
• Sharks: attack and eat nearly
anything that smells like food,
many rows of teeth
• Rays and skates: hunt on
ocean floor, crushing mollusks,
crustaceans, and small fishes
with their teeth
 Examples:
trout, tuna, goldfish
 Have jaws, scales, a pocket on each
side of the head that holds the gills,
and a skeleton made of hard bones
 Fins: help the fish stay upright
 Scales: cover the body by overlapping
each other
 Gill Pocket: holds the gills
 Swim Bladder: helps stabilize the fish at
different depths in the water