Download IV Osteichthyes PPT - Cherokee County Schools

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Means fish with bony skeletons
There are over 20,000 species of bony fish
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Most fish live in the epipelagic zone
1.
2.
3.
Tail Fin (CAUDAL FIN)
Paired Fins (PECTORAL and PELVIC FINS)
Medial Fins (DORSAL and ANAL FINS)
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Ray-finned fish have fins supported by a fanshaped array of bones
Makes the fin light, collapsible, and easy to
move
Ray-finned fishes are the most diverse group
of living vertebrates, making up nearly half
of all vertebrate species.
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Caudal fins have different shapes
1. Homocercal --> Top and bottom halves the same size
a.
Rounded (Low A.R.)
b.
Truncate (Intermediate A.R.)
c.
Forked (Intermediate A.R.)
d.
Lunate (High A.R.)
2. Heterocercal --> Top half different size than bottom half
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Heterocercal – often found on sharks
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Most fish have a complex sense of smell
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Fish also have taste buds
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Used to detect prey, mates and predators
Smell is detected in the nares (nostrils)
Found in the mouth, fins and skin
Catfish have taste buds on barbels (whiskers)
Rely on vision
Eyes focus by moving closer or further from the
object they wish to view
 Covered by a nictitating membrane – clear
membrane that allows the fish to see while
protecting the eye
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Sight – some fish can see color and can see in
very dim light
Hearing – fish can hear
Smell – fish have nostrils used for smelling
Touch – fish can feel objects against their
skin
Lateral line- A system of canals on the sides
of fishes that helps fish detect changes in
pressure, vibrations and currents
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Fish “hear” via their lateral lines, a line of
pressure sensors running along each side of
the fish that pick up pressure waves (= sound)
in water. When someone pounds on an
aquarium, that creates waves of pressure in
the water that, to the fish, would be
analogous to cupping your hands and
pounding on your ears--NEVER POUND ON
A FISH TANK!
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Detect changes in pressure and vibrations and
currents
Detect prey
Swim together in a school
Detect predators on the side or behind them
Pick up vibrations from the swimming
together of other animals
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Most fish swim with an S motion
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Controlled by bands of muscle called myomeres
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A rhythmic side to side moving from the head to the tail
Run parallel along the sides of the fish
Visible in fish you eat
Makes up 75% of the fishes weight
White muscle is used for bursts of speed
Red muscle is used for constant locomotion
The fins are used like rudders to change direction in
the water
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Some fish move by moving only their fins and not their body
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To maintain buoyancy the fish will either:
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Adjust the density of its body by using a SWIM
BLADDER
They will adjust the density of the components of
their insides (they will consume lighter weight
ions and leave the heavier ones in the surrounding
water)
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A swim bladder is a balloon-like structure
that is:
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inflated to make the fish rise higher in the water
or deflated to make the fish sink lower
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Some fish like Tuna do not have a swim
bladder and must swim fast to prevent
sinking
Some fish like catfish do not have a swim
bladder and spend their life on the bottom
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Fish use gills to absorb oxygen from the
surrounding water
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Gill Arch - stiff structure that supports the
gill filaments and the gill rakers
Gill Rakers – prevent food from clogging up
the gill filaments
Gill Filaments – fingerlike projections where
oxygen is absorbed and carbon dioxide is
removed
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Freshwater
fishes
never drink
 Lots of
nephrons
 Ions are
reabsorbed
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Marine fishes
Drink
constantly
 Less blood is
filtered
 Water is
reabsorbed
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Most fish have internal sex organs that we
cannot see.
fish gonads (sex organs) produce gametes
(sex cells) only at certain times.
These times must be the same for both males
and females and must be timed to the most
favorable conditions.
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Fish may only reproduce when there:
1. Is enough of the right kind of food
2.There are enough hours of light each day
3. The water is the right temperature
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Includes:
 Courtship: a series of behaviors designed to
attract mates
 Spawning: a release of gametes into the
water
 Copulation: a direct transfer of sperm into a
females body
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Most fish reproduce by spawning.
 This is when the female swims and lays
eggs on plants or sand in the water
 The male fish swims behind her depositing
sperm into the water where some of it may
land on and fertilize the eggs
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Some fishes are hermaphrodites. They
have both male and female gonads
Hermaphrodism is more common among
the deep-water fishes. (Gourami)
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Sex Reversal
 Males may change to females or females to
males (ex. Clownfish)
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Among some species of anemone fishes a
single large female who mates only with a
single large dominant male inhabits each sea
anemone. All others are small non-breeding
males. If the female disappears her mate
changes into a female and the largest of the
non-breeding males becomes the new
dominant male. The new female can start
spawning as soon as 26 days after her sex
change.
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Fish can be either carnivorous or herbivorous
(mostly carnivorous)
The teeth will tell you what they eat
 Used for grasping and holding the prey
 Prey is usually swallowed whole
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Usually have one preferred food source
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A type of fish, anemone, urchin, etc.
Fish that feed on algae are called grazers
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Territoriality
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An established area that the fish protects against
invaders
Some are only territorial during mating period
others are for life
Thought this helps ensure there is enough food
for the fish
Defended by aggressive behavior like making
themselves appear larger or by chasing other fish
Fights are rare
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Schooling
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4000 species of fish school at some point in their
lives
Can provide protection against predators
 Can cause confusion
 Less likely to be the one eaten if there are thousands
of other fish around you
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Can increase swimming efficiency by reducing the
drag of the water
Can be advantageous for mating or feeding
Characterized by having:
 Bone in their skeleton
 An operculum covering the gill openings
 A swimbladder or lungs
 True scales
 Paired fins
 Homocercal tail (Exception lungfish – diphycercal)
 Mouth terminal
 Two chambered heart
 Sexes separate (Sex reversal in some)
 Fertilization external for most
 Excrete ammonia
The bony fishes are the most diverse class
of fish. ~24,000 species
Osteichthyes are divided into two subclasses
 The lobe-finned fish (Sarcopterygians)
 The ray-finned fish (Actinopterygians).
*Most modern fish are members of the rayfinned, Teleost subdivision.
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Sarcopterygians are the fish most closely
related to modern amphibians, reptiles,
birds, and mammals = terrestrial
vertebrates
This subclass includes the lungfish and
coelacanth. Coelacanth were thought to
have become extinct at about the same
time as the dinosaurs, until a live
specimen was found in 1938
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Characteristics:
Muscular lobe associated with fins
Have lungs for gas exchange
Live in areas with seasonal droughts
Can breathe air if water stagnates
Can withstand desiccation
Burrow in the mud
Have enamel on the teeth
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Can survive drought by remaining in
aestivation for 6 months or more
Aestivation = dormant state
After rain fills the lake or riverbed
Lungfish emerge from their burrows to
feed & reproduce
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Cosmoid scales
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Ray-finned fish (Fins lack muscular
lobes)
Have swimbladders to regulate
buoyancy
~23,900 species
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Include sturgeons and paddlefish
Sturgeon eggs make caviar
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Superorder Ostariophysi
Order Cypriniformes (minnows, carps)
Order Siluriformes (catfish)
Superorder Protacanthopterygii
Order Esociformes (pikes)
Order Osmeriformes (smelts)
Order Salmoniformes (salmon, trout, whitefish)
Superorder Paracanthopterygii
Order Gadiformes (cod, hakes, pollock)
Superorder Acanthopterygii
Order Percoidei (perches, snook, basses)
Order Pleuronectiformes (flounders, soles)
Order Perciformes (mackerel, tuna, swordfish)
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Teleosts are modern day ray-finned fish
Use their fins and body wall to push
against water for locomotion
Some secrete mucus to reduce friction
Most teleosts are carnivores swallowing
prey whole
Herring & paddlefish are filter feeders
Teleosts have pyloric ceca (outpockets in
the small intestine to increase absorption)
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Found on non-teleost
bony fishes
Usually diamond
shaped bony scales
“Heavy armor”
Gars – Alligator Gar
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Found on teleost
fishes
Light, thin, &
flexible
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Teleost fishes
Have comblike
ridges along the
exposed edge to
reduce friction
(drag)