Transcript Fish ppt 2012

PHYLUM CHORDATA
Vertebrates
Fish, amphibians, reptiles,
birds and mammals
GENERAL TRAITS OF CHORDATES
1.Bilateral symmetry
2.Complete digestive system
3.Closed circulation with a
ventral heart
4.Dioecious
5.These traits present during some
part/stage in their life:
a. Notochord- becomes spine
b. Dorsal nerve cord- becomes
spinal cord
c. Pharyngeal gill slits
d. tail
GENERAL TRAITS OF FISH
1. Streamlined bodies
2. Mucus covered bodies
3. Paired fins help with steering &
balance.
4. Maintain buoyancy
5. tissues & bones not as heavy
6. Respiration- gills; water
enters mouth, passes over
gills , gases exchange,
water leaves w/CO2 thru
gill slits.
7. Circulation2 chambered heart
a. 1 atrium & 1 ventricle
b. Path of Blood=
body-atrium-ventricleafferent arteries-gillsefferent arteries-body
8. Nervous- brain &
spinal cord
9. Sensorya. Good sense of
smell
b. Poor eyesight
c. Lateral Line
System- sensory
pits in skin
attached to fluid
filled canals
under skin; can
detect
movement.
10.Excretory System- 2
kidneys
a. Osmoregulationregulation of water &
ions (salt) in body.
b. Freshwater fishwater moves into
blood due to osmosis;
urinate a lot to
remove excess water
c. Saltwater fish- water
moves out of blood
into salty water;
urinate very little to
retain water.
11. Digestive Systema. Teeth- modified
scales for grasping
prey
b. Swallow prey
whole or in large
chunks.
c. Large stomach for
storing infrequent
meals.
THREE
CLASSES
OF
FISH
CLASS AGNATHA
1. EX: hagfish & lamprey
2. Jawless fish w/smooth skin- no scales
3. No paired fins
4. Cartilage skeleton
5. Gills open to water
6. Fertilization- external
7. Oviparous- lays eggs externally
8. Lampreya. Suckerlike mouth
b. Teeth & rasping
tongue scrape
scales off host.
c. Suck blood of fish
9. Hagfisha. Live buried in sand &
mud
b. Mouth with 4 pairs of
tentacles
c. Enter dying/dead fish
thru mouth
d. Eat contents of body,
leaving sack of skin &
bones
e. Secretes green slimy
mucus to deter predators
CLASS CHONDRICHTHYES
1. EX: sharks, skates, rays
2. jaws
3. Paired fins
4. Cartilage skeleton
5. Gills open to water- gill slits
6. Dermal placoid scales- “dermal denticles”
a. Point backward- reduces friction in water
b. feels like and used to be used as sandpaper.
7. Buoyancy- oily livers
8. Special Digestive Adaptations:
a. Teeth in rows
1. ratchet forward when one is lost.
2. New row of teeth develop every 7-8
days
b. Rugae- folds in stomach that expand
to hold large meals
c. Spiral valve- increases absorption of
nutrients (like human villi)
9. Special Respiratory Adaptations:
a. Ram Ventilation- some sharks
1. Swim with mouth open to force water
into mouth over gills.
b. Spiracles- holes behind eyes
1. Used for breathing while eating.
10. Special Sensory Adaptations:
a. Lateral Line system
b. Ampullae of Lorenzini1. pits in snout that detect impulses or electrical
currents in water.
2. Used to find
prey, mates,
identify predators.
3. Helps sense in
murky or
turbulent water
11. Fertilization- internal
a. Males have penislike structure called
clasper for
inseminating female.
Male shark
Female shark
b. Development of eggs
1. Oviparous- lays eggs
2. Ovoviviparous- eggs hatch
inside mother
–
No placenta so babies that
have hatched sometimes eat
other eggs &/or siblings that
have hatched.
–
EX: Great whites & nurse
sharks
3. Viviparous- “Pups” are
attached to mother by
placenta
1. EX: bull shark, mako,
whale shark, hammerheads
12. Smallest- dogfish shark (1 meter)
13. Largest- whale shark (10 meters &
filter feeds)
14. Skates & rays find food along bottom.
JOURNAL
• Tell me three things you learned from the
shark dissection last class.
CLASS OSTEICHTHYES
1. EX: tuna, bass, bluegill, seahorse
2. Bony fish
3. Jaws
4. Paired fins
5. Bony skeletons
6. Gill openings covered with operculummuscular plate that pulls water into
mouth.
7. Buoyancy- swim bladder
a. Increase air- fish rises
b. Decrease air- fish sinks
8. Special Sensory Adaptations:
a. Ossicles- pick up vibrations in water
for hearing
9. Reproduction:
a. Fertilizationexternal
b. Oviparous
c. Males create nest.
Females lay eggs.
Males fertilizes eggs.
Sometimes female
protects eggs until
hatching.
d. Spawning- return
to river born in to
reproduce (salmon)
10. Scalesa. Can be used to identify fish
b. Can estimate age of fish with rings (annuli) on
scales.
1. Cosmoid
2. Ganoid
3. Cycloid
4. Ctenoid
Pay close attention to these
pictures so that when you are
dissecting the shark you
recognize organs!
1. Shark skin was once used for
a. Sand paper
b. Clothing
c. Writing utensils
2. Bony fish belong to the class
a. Agnatha
b. Chondrichthyes
c. osteichthyes
3. Sharks reproduce using ___ fertilization
a. External
b. internal
4. Which type of fish has placoid scales?
a. Bass
b. Stingray
c. hagfish
5. The structure in bony fish that maintains buoyancy
is
a. Operculum
b. Swim bladder c. Oily liver