 Phylum=
Chordata
 Evolved- 530 million years ago
 Ancestors are tunicates and
lancelets
 1.
Pharyngeal gill slits
 2. Dorsal Hollow Nerve Cord
 3. Notochord
 4. Tail lying posterior to anus
Habitats
range from the
intertidal to the deepest
trenches.
1.
Human nutrition
2. Fertilizer
3. Recreational fishing
 1.
Destruction of habitats
 2. Pollution of Coastal Waters
 3. Overfishing
90% of all of the
world’s fisheries
will be depleted
by 2050.
 Have
shell.
a cartilaginous bone or
Fish
that lacked both
jaws and paired
appendages.
Seafloor
Scavengers
 1.
Hagfish
 2. Lampreys
 3. Sharks and Rays
 4. Ray finned fishes
 5. Coelacanths / lobefins
 6. Lungfishes
Lack vertebrate
 No scales
 Small brain, eyes, ears, and nasal openings
that connect with the pharynx and slime
glands
 Slime eels
 70 species, females outnumber 100 to 1
 Produce milky slime when disturbed ->
protection -> so much it coats the gills of
the other fish and suffocates it.

 Used
for their leather qualities
(high demand)
 Skulls made of cartilage and
lack jaws and a vertebrate
 Dental plates grasp prey and
latch onto flesh
 Bottom dwelling scavengers
 38
species, parasitic feeders
 The skeleton is made of cartilage
that contains no collagen and they
lack jaws
 Oldest living lineage of vertebrates
 Oral disk and rasping tongue with
horns to grasp prey, literally
puncturing a hole in the body and
sucks the organs and tissues out.
 Anadromous->
migrate from SW to
FW to spawn. The males build a
nest out of stones and the females
come along and attach
themselves to the stones. The male
attaches itself to the back of the
female-> male sheds sperm->
adults die-> larva hatch-> migrate
and hide in the river bottom-> live
for 7 years and then go back to the
sea to lay eggs and die.
Sharks and Rays= Cartilaginous
fishes
•Class Chondrichthys
•Skeletons are cartilage
•Jaws, paired fins, sandpaper
like placoid scales
•970 species
 Top
predators
 Highly specialized
 Whale sharks, basking sharks,
and megamouth sharks =
zooplanktivorous -> filter feed
small planktonic animals.
http://www.youtube.com/watch?v=Rx
hqBmnZv8Q
Carnivorous
 Greatest # inhabit temperate and tropical
waters
 Swim with sideways sweeps of their caudal
tail fin
 Heterocercal – dorsal portion is longer than
ventral.

Pelvic fins of males -> claspers-> transfer
sperm from the male to the female.
 Ventral mouth with lots of rows of teeth->
always replaced and the nonfunctional
inner rows move forward to replace.
 Upper jaw / teeth slice through the prey’s
flesh and tear (30,000 teeth in a lifetime).
 Swallow food whole because their jaws
don’t move back and forth.

 Exploited
for fins, meat, oil,
leather, cartilage, and sport
 Shark fin soup
 Flattened
bodies
 Spiracle on the top of the head ->
water is drawn in through spiracles
and passed out over the gills. An
aeration system prevents the gills
from getting clogged with sand.
 Crush prey except for manta rays->
feed on plankton.
 Eagle rays / manta live in open
water, others are bottom feeders.
 Defenses
-> stinger. Electric rays
have electric organs in head= 220
volts that they use for navigation
and stunning of prey.
 Venom (skates don’t have a
stinging spine)
 Sawfish and guitarfish -> series of
barbs along snout-> shake head /
“saw”
 Skate wings= scallops
 Skates:
› Swim with wave
action
› Fleshier tails
› No venom
› Leathery egg
case called a
mermaids purse.
 Rays:
› Swim by moving
fins up and down
like a bird
› Streamlined tails
with barbs and
venom
› Give birth to live
young
26,000 species- most numerous
 Characterized by their swim bladder, fin
rays, bony skeleton, bony scales in skin,
terminal mouth, operculum that covers
the gills and protects them.





Heterocercal tails
Marine sturgeons
Cartilaginous
skeleton
Ganoid scales (thick
/ heavy)



Homocercal tail
Cycloid and Ctenoid
scales
Maneuverable fins
Medium fins-> one or more dorsals for
stability
 Paired pectoral / pelvic fins -> steering
 Ex- Chinook salmon, bass, trout, grouper





Lobe finned fishes
Thought to be extinct until 1938 when fisherman
discovered them in the West Indian Ocean.
Thought it was extinct 60 million years ago
http://www.youtube.com/watch?v=ZQMm5HN
1Ums
Living fossil
 Before this they were only known as fossils
that were 400 million years old
 2nd one caught in 1952- Madagascar /
Africa
 Natives eat it regularly -> dry and salt it
and eat its flesh and use its skin for
sandpaper.
 Little is known

›
›
›
›
›
6ft in length
Large blue scales
Feeds on fish and squid
Stand on fins
Rotate fins 180 degrees
 The
second lineage of living lobe-fins
 All are found in the Southern Hemisphere
 Only found in fresh water, generally in
stagnant ponds and swamps
 Can gather oxygen from both the air
through their pharynx and the water
through their gills.
 http://www.youtube.com/watch?v=tqW
ciuuKn3c
 Fins->






Stiff rays covered by skin.
Dorsal= stability
Ventral= stability
Caudal= propelling
Anal= stability
Pectoral= locomotion / side to side movement
Adipose= stability (2nd dorsal)
 Slime
cells are going to aid in
protection against bacteria,
etc.
Lie in dermis and overlap for protection
(armor)
 Placoid-> similar to teeth (sharks, rays->
sandpaper)
 Ganoid-> flat, cover fish with little overlapping
(GAR and many bony fishes)
 Cycloid-> oval shaped with growth rings
(carps)
 Ctenoid-> spines cover one edge (cichlids)

 Located
under gill slits (5 slit
opening)
 Tissue between the slits on each
side= gill arch.
 5 gill slits and 4 gill arches= gills are
mounted
Connected to sensory cells / nerve fibers
 Line is from gills to tail fin
 Detect minute electrical currents in the
water, echolocation
 Function-> Schooling

http://www.youtube.com/watch?v=N3
CXUO0jxNQ
 Buoyancy!!!!!
And it is a gas
filled sac that offsets the
density of their bodies.
 Fish have to constantly swim if
they want to stay afloat!
 More
gas must be added to the
swim bladder or bladder will
compress and the fish will
become denser and sink.
 Ascends-> Removes gas= when
arise too quickly the swim bladder
comes out of their mouth.
 Mackerels,
sharks, skipjacks,
scorpion fishes, deep sea fish->
have to keep swimming or
they sink.
Body
Shape!!!!
Correlates with its habitat
•
•
•
Very high and narrow tail=
Fusiform body shape
Which allows them to move
through the water with
great efficiency and speed.
Examples-> sharks, tunas,
marlins
 Helps
them navigate / swim
through tough spots, especially
coral reefs.
 Ex- Butterfly fish, Angelfish, Sea
grass fish
 Flounders
 Depressed
/ flattened body.
 Flounders begin life looking like a
normal fish but during their
juvenile stage they begin to swim
on their side and eye migrates
from the bottom side to the upper
side.
Enlarged
pectoral fins to
support round body.
Ex.- Anglerfish, Oyster
toadfish, scorpion fish
 Colors
serve as many functions:
› Camouflage
› Communication
› Conceal themselves from prey
› Attract mates
› Warn other fish that they are
poisonous
1.
Pigments (Biochromes)
2. Structural Colors
Cells where the pigments are found in the
center of the body cell.
 These allow fish to change colors to match
their surroundings.
 Darkness depends on how much of the
pigment is dispersed throughout the
cytoplasm.
 Not all chromatophores contain the actual
pigment color that they appear. Some work
on different principles other than selective
absorption/reflection.

Chromatophore
Pigment
Type
Colors
Melanophore->
Most common
Melanins
Color
Dispersed= darker
Contract= lighter
Black and Brown
Xanthophore
Pteridines and
Carotenoids
Color
Red and orange
Erythrophore
Pteridines and
Carotenoids
Color
Orange and
yellow
Iridophore
Guanine and
other Purines
Refelctive
White, Silver, Blue,
and others
Epidermis
Slime Cells
Dermis
The xanthophore or filtering layer
The iridophore or reflecting layer
The melanophore or absorbing layer

Fish can alter their color by moving
pigments around. For example, the
flounder can alter its body pattern and
color to match its immediate
environment.
http://www.youtube.com/watch?v=kO
embW28AGw
http://www.youtube.com/watch?v=Hc
8Gcxuj3lI
 Melanins
 Carotenoids
 Iridophores
By
light reflecting from
crystals in specialized
chromatophores called
iridophores.
Dark
colored back that
fades to a pure white
belly.
 Sharks->
when viewed from
the top the dark blends in,
from the bottom it’s the same
thing.
 Tuna
 Marlin
 Where
vertical lines and eye spots
interrupt the background color of
the body.
 Ex- butterfly fish-> eyespot
confuses predators
 Red Drum
Breaks
up the pattern
and makes it more
difficult for predators to
see.
 Very
bright, elaborate patterns
that may advertise territorial
ownership, allow schools to stay in
contact, or sexual displays.
Bright colors that advertise to predators
that I’m dangerous / poisonous to eat.
 Lionfish, stonefish,

 Blend
in with the environment.
 Camouflage themselves to
avoid predators and ambush
prey.
 Example- Scorpion fish- looks
like rocks
 Ex- Pipefish- mimic sea grass
http://www.youtube.com/watch?v=K
OJhIl-qlWY
They possess a strengthened girdle with
extra muscles to facilitate their walking,
which is done using their pectoral fins
with tail supporting the end of the body.
 They are able to climb tree roots and
surface for long periods of time out of
the water. They use their unusual ability
to hunt down terrestrial insects and
surface dwelling crabs.


Hide or bury themselves into the sand for
protection from predators, habitat and
finding prey.
Gets its power and speed from its caudal
fin by moving it from side to side with
powerful strokes.
 They swim very fast near the surface of
the water and if a predator is near, they
will reach speeds of 15-20 mph and then
break the surface of the water.

http://www.youtube.com/watch?v=O
mWRCdUw17E
Swim
normally by using their
pectoral fins that would be
comparable to our arms.

Some fish just ride with the current to
save on energy while some swim against
it like salmon
 Use
gills to extract oxygen
from water and eliminate
carbon dioxide as an aid in
maintaining proper salt
balance.
 In
the opposite direction from the
incoming water creating a
countercurrent multiplier system,
which maintains a stable gradient
that favors the diffusion of oxygen
into and carbon dioxide out of
the body.


Countercurrent= blood in the capillaries flows in the
opposite direction of water.
Low-oxygen blood enters the capillaries and doesn’t
encounter water until it reaches the end of the gills,
which is low in oxygen. As blood travels in the
direction opposite to the water, it encounters
"fresher" water with higher oxygen concentrations.
Then along the capillary, a steep diffusion gradient
favors transfer of oxygen into the blood.
To
keep the blood
oxygenated
 1.
Water enters the mouth
 2. Mouth cavity contracts and the
chamber surrounding the gills
pushes the water across the gills.
 3. Gill chamber contracts and the
water is released from the
operculum (moveable flaps of the
tissue that covers the gills).
Ventilate their gills by swimming at high
speeds with their mouth open.
 Ex- sharks, tuna, swordfish.

When an organism maintains the proper
concentration of solutes and water in its
body fluids.
 Rectal gland= excretes
 Ray finned fishes compensate for water
loss by drinking water, removing the salt
using the gills, and keeping the
“freshwater.”







Lose water by osmosis
(movement of water across
a semi-permeable
membrane.
Gains salt by diffusion
(movement from areas of
high to low concentration).
Excretes salt through the
gills through specialized
chloride cells.
Very little water is lost in
urine.
Kidneys have small or no
glomeruli (tufts of capillaries
that filter blood from the
urine)
Produce a small volume of
ISOTONIC urine.






Gain water by osmosis, salt
diffuses in through the gills.
They do take some salt in
from food.
Kidneys with large
glomerulli which re-absorbs
urea.
Have lots of urea and
TMAO (trimethylamine
oxide- metabolic enzyme)
Salt excreting gland in the
anal area.
Excretes a large amount of
hypotonic urine.
Retain
urea and TMAO in
their blood as well as the
body fluids that balance
the solute concentrations of
the saltwater.
Reduce
the levels of
nitrogenous waste in their
body fluids by excreting it
through their rectal gland.
 Drink
seawater, remove excess
salt, retain water, and the
specialized chloride cells on
the gills eliminate salt.
 Large
quantity of squalene in their
livers.
 Squalene= oily material, density is
less than seawater.
 Allows to offset sharks density.
Nervous system=
Brain, spinal
cord, nerves,
and sensing
receptors
 Has
a nostril on each tip of its
nose “hammer” and as it swims it
moves its head from side to side,
increasing its ability to smell. When
the smell is equal in both nostrils
that’s when they know the prey is
dead ahead.
 Two
canals that run the length of the
body.
 Vibrations in the water cause the fluid
in the canal to move cupula which
then sends a signal to the animals
brain.
 Function= locate prey, schooling, and
avoid predators
Sensory
receptors in the
lateral line that detects
vibrations.

Regulation / balance membrane sacs
(three layers) and they have otoliths (ear
stones) which work with the maculae /
sensory receptors where sound is
detected through vibrations of maculae
and otoliths.
Sharks->
used for protection
Monocular vision-> each
eye sees its own
independent field
 Sharks
sense electrical currents
in the water by scattered
organs that are over the top /
sides of their head.
 May use to sense prey.
If
they were to chew it,
then they would block
the water flowing over
their gills.

Crush prey with jaws

Tiny mouths and they feed on little krill
and coral polyps

Wait for prey on the bottom, motionless
-> springs up and grabs the fish
http://www.youtube.com/watch?v=dU
-DizDMJQg&feature=related
 Camouflaged
on the bottom,
motionless-> spring up and
grab fish
http://www.youtube.com/watch?v=G
bcdeI7psUc
http://www.youtube.com/watch?v=o5
z0jusJukM&NR=1&feature=fvwp

Scrape algae off rocks with beaklike
mouth

Several fish take shelter in the crevices and holes of coral reeves (sing: coral reef).Corals are
found in shallow warm seas all over the world. In the Caribbean waters, lives a fish called,
Parrot fish. It builds cocoons in the reef crevices.
Parrot fish is beautifully colored. Its mouth is drawn in the form of a beak that resembles the
beak of a parrot. Hence, the name.
Parrot fish feeds on algae that are found growing on the coral reef surface. The fish scrapes
the algae with its strong beak. By feeding on the algae, the Parrot fish protects the coral reef
from algal attack. The coral reef is the home of the Parrot fish.
During day time, Parrot fish join other fishes and swim away from coral. When the night falls,
the Parrot fish returns to the reef. It searches for a safe hiding, where it can sleep and spend
the night...
After finding a suitable crevice, the Parrot fish builds a cocoon nest. It is a mucous cocoon.
Mucous is a sticky substance secreted by the skin of the fish. The mucous cocoon of the Parrot
fish is transparent. It masks the scent of the fish and protects from predators, while the fish is
asleep.
If however any predator disturbs the cocoon, the Parrot fish will wake up from its sleep and
move away in swift action. The mucous cocoon is shattered. It forms an opaque cloud in front
of the predator which is left confused leaving enough time for the Parrot fish to escape...
In the morning when the sun rays light up the waters, the Parrot fish wakes up from its sleep. It
leaves its cocoon nest.
The Parrot fish uses the mucous coon as its sleeping bag. Every night it builds a new sleeping
bag cocoon. It sleeps at different places in the coral. It does not use the same bed or the
same sleeping bag!!

Filter feeds using gill rakers
http://www.youtube.com/watch?v=u
QrBwN39LJI

Suck up bottom sediment
Pufferfish / Porcupine fish = swallow air
and blow up
 Flying Fish= use large pec fins to glide out
of the water
 Surgeonfish= razor sharp spines on side
and the tail flips out like a switch blade
 Scorpionfish= Venom glands in dorsal,
anal, and pelvic fins

 The
path of sperm and eggs is
different for each type of fish:
 Three modes:
› Oviparity
› Ovoviviparity
› Viviparity
Eggs are shed into the water and
embryos develop outside the mothers
body.
 Examples-> Whale sharks, bullhead
sharks, skates, Zebra shark, horn shark

Internal fertilization and eggs hatch in
mom uterus and are nourished by yolk
sac.
 Sand tiger, basking sharks, thresher
sharks, rock fishes

Young attach to uterine wall or uterus
and feeds off uterine milk.
 Ex- hammerheads, surf perches.

 Pelagic
Spawners-> commercially
important fish.
› Cod, Tuna, sardines, parrotfish, wrasses
› Release vast amount of eggs into the
water
› Advantage= widely distributed offspring
› Disadvantage= high mortality rate

Live closer to shore and produce eggs
that are generally larger than those of
pelagic spawners and have a large
amount of yolk.
› Non-bouyant eggs
› Eggs spread over rocks and sea grasses
› Large number of eggs

Example are Grunions
› Hides its eggs- no parental care. They swim
ashore at high tide / full moon, burrow into
the sand and deposit eggs.
› Males curl around the buried females and
fertilize the eggs as they are laid. The eggs
stay in the sand until the next high tide when
they are washed to sea.
http://www.youtube.com/watch?v=0
MmJKUSsQyI&feature=related
 Care
for their offspring until they
hatch and often through the
larval stage.
› Males guard offspring-> few days til
4 months old.
› Damselfish, blennies, gobies
› Territorial
 Female
lays eggs in the mouth
of the male and he incubates
them until they hatch.
› Jawfish
› Spit them out to aerate and
rotate and then such them
back in.
http://www.youtube.com/watch?v=YN
mnnnAe-RM&feature=related

Organisms have both testes and ovaries
at some point in their life.
› Synchronous= functional gonads of both
sexes at one time
› Sequential= changing from one sex to
another
› Protogyny= change from females to males
› Protandry= change from males to female.
Hamlets- synchronous hermaphrodites
 Cleaner Wrasse- sequential
hermaphrodite
 Clownfish- protandrous sequential
hermaphrodites


http://www.youtube.com/watch?v=6lp8
7hrb-5I&feature=fvsr
Group of individuals – highly organized
 Behavior = shoaling -> social reasons
 Increase efficiency in finding food (more
eggs) to detect predators
 Reproduction -> keeps sperm and eggs
closely together.

http://dsc.discovery.com/videos/super
swarm-fish-vortex.html
http://www.youtube.com/watch?v=X_
urruBqlQo







Daily / seasonal
Feeding / predator avoidance
Spawning, change in temperature
Tuna- winter in California / Oregon and
Japan in the summers
Mullet- FW or estuaries
Catadromous-> move from FW to SW to
spawn
Anadromous-> move from SW to FW to
spawn
Best known catadromous fish
 In the fall the adults migrate down
coastal rivers to the sea and they
change color from a dull olive to a silver
and their eyes get larger.
 Take 2 months to reach the Sargasso Sea
where they spawn
 Take about 1 year to make this journey
 Spawn 900 ft. down-> adults die after
reproducing

Hatchlings develop into leaf like
leptocephalus larvae and start to migrate
back to the rivers of Europe (takes 3 years)
and North America (takes 1 year).
 When they reach the coastal rivers they
metamorphosis into juvenile eels called
“elvers” -> they migrate into streams and
estuaries.
 Males remain in FW to 4-8 years
 Females reach sexual maturity at 12 years
 Will return to the breeding grounds of the
Sargasso Sea.

Anadromous
 Pacific and Atlantic
 Pacific-> die after their journey /
spawning
 Atlantic-> return multiple times
 Salmon lay their eggs in shallow
depressions called redd.
 Develop into alevins (newly hatched)->
Parrs (1-5 years)-> smolts (5+)

Return to their native stream when it is
time to spawn again-> some say that they
find their native stream through olfaction
(smell chemicals in the soil)
 “imprinted” with odor knowledge
 Pheromones released by smolts
 Populations have been reduced due to
pollutants, dams, human activity
