Fishes Flashcards
FLASHBACK: what tare the characteristics unique to chorodates
- notochord
- post-anal tail
- dorsal hollow nerve cord
where are pharyngeal slits located?
on lateral surface of the head
pharyngeal slits seam to be an _______ trait in deuterostomes
ancestral
In vertebrates, pharyngeal tissue is supported by what?
arches
What is the function of the pharyngeal slit?
filter feeding - water goes in and out through these slits
How do vertebrates breathe?
- water comes in though the mouth and passes through the slits
- O2 and CO2 can be exchanged across a respiratory surface = gills
where are the gills located?
between the slits
how are the gills supported?
by the arches
Gill slits =
pharyngeal slits
gill arches =
bars between the slits
where are the gill filaments located?
on the gill arches
how many pairs of gill arches do bony fish have?
four
operculum is a
gill cover
the structure of the gill filament is
a thin, vascularized, high surface area
where does gas exchange occur?
in the capillary beds in the gill filaments
Water and blood in which directions?
opposing
the water comes from the ____ across the filament between the _____
mouth ; lamella
when is efficiency of gas exchange low?
when the inside medium (in this case the blood) flows in the same direction as the outside medium (in this case the water)
Why does blood flow in the opposite direction to water flow?
so that concentration gradients are maintained along the length of the exchange area
the circulatory system of fish is
closed
describe the circulatory system
arteries (away from the heart ) –> arterioles –> capillaries
–> venules (towards the heart) –> veins
how many circuits do fish have?
one.
what circuits do we have?
pulmonary circuit and systemic circuit
pulmonary circuit
heart –> lungs –> heart
systemic circuit
heart –> body –> heart
where is the fish heart located?
ventrally
characteristics of vertebrates
axial skeleton
characteristics of vertebrates
appendicular sksleton
characteristics of vertebrates
closed circulatory system
where are organs suspended in vertebrates
coelom
who was derived from fish?
ALL OF US.
fish make up ___% of vertebrate diversity
50
Agnathans
jawless fish
Jawless fish are considered vertebrates but NOT
gnathostomes
what are the two groups of jawless fish
lampreys and hagfish
jawless fish do NOT have
paired fins
swim bladder
scales
Hagfish are s_________
Scavengers
what allos hagfish to apply more force to pull stuff out of the ground?
knot tying
what do hagfish use mucus for?
fight predators
Lamprety do not have
jaws
How were jaws formed?
by the fusion of gill arches
how were teeth formed?
the evolution of scales in the mouth
what is the largest fish to ever live
megalodon
what do paired fins enable?
more active swimming - steering, stabilizing and lifting `
two types of gnathostomes
cartilaginous fish
bony fishes
Types of cartilaginous fishes
sharks
skates
rays
cartilaginous fishes have
jaws
paired fins
scales
cartilaginous fishes do NOT have
a swim bladder
What’s the smallest living shark
dwarf lantern shark
the largest living shark
whale shark
Bony fishes
largest verebrate group
Bony fishes have…
jaws
opercula
paired fins
scales
opercula
gill cover
what is the opercula used for
to suck water into the mouth
what do Bony fishes use their swim bladder for?
- as a flotation device
- it enables neutral buoyancy
- gas regulated by gland in bladder by swallowing/burping air
name the two type of bony fishes
- ray finned fish
2. lobe finned fish
most fishes are
ray finned fish
our ancestors are
lobe finned fish
