BIO 474 Lecture Notes - Lecture 2: Porichthys Notatus, Deep Sea Fish, Weberian Apparatus
Largest clade of vertebrates
euteleosts
Weberian apparatus
a series of interconnected bone ossicles
connecting from swim bladder (air filled) up to
the auditory structures in the ear
swim bladder
filled with air so the resonation of sound can
occur and vibrate the ossicles causing a
transduction to the auditory system
Examples hearing with and without
swimbladder/weberian apparatus
Tuna: no swim bladder, needs louder sounds to
hear
Goldfish: has swim bladder and weberian
apparatus, can hear much softer sounds
anguilliform
when the animal can bend its body into at leas
half of a sine wave (eel)
carangiform
when the animal can bend its body into less
than half of a sine wave (trout)
ostraciiform
very little bending of the tail, pretty much a
slight wagging (boxfish)
two types of drag an organism experiences
viscous (frictional)
inertail (pressure)
Profile ratio
frontal area/surface area (0.23 is average)
viscous (frictional) forces
proportional to amount of surface area
force exerted along the length of the fish
inertial (pressure) forces
proportional to the force exerted on the frontal
area of the organism
streamlined fish have a lot less of this
Reproductive biology of freshwater teleosts
-produce and care for relatively few young
hatching from large eggs
-eggs are attached to some form of substrate
-hatchling (fry) develop forms and behaviors of
adults quickly
reproductive biology of marine teleosts
-produce large numbers of small young
-eggs drift in the open ocean
-hatchlings are larvae and look very different
from adults until metamorphosis
Seahorses reproduction (teleosts)
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males carry the eggs
after female transfers eggs to pouch he ferts.
and carries eggs
causes certainty of paternity which makes the
fathers invest in their young
certainty of paternity
knowing that the progeny belong to a paternal
figure
causes the paternal figure to invest more in his
progeny
if there was no certainty of paternity, the
paternals would not invest because they do not
know if their genes are being passed so they
would rather invest energy in reproducing as
much as possible rather than investing in caring
for a baby that may not carry their genes
plainfin midshipman teleosts reproduction
location
shallow rocky intertidal zone (marine)
female plainfin midshipman teleosts
discrete seasonal period of breeding
respond to the low hum of the territorial males
response to stimulus is steroid dependent
lose sensitivity out of season because it is costly
to maintain
Territorial male plainfin midshipman teleosts
controls a group of rocks that are limited
resources
females value these rocks for spawning
emit a low hum to attract females
hum is steroid dependent
better fish means better rocks
sneaker male plainfin midshipman teleosts
small like a female
sneaks in and fertilizes the eggs as the female
lays them
African cichlid
only one dominant male in the area and
multiple subordinate males
dominant is the only one who mates
eye bar made of melanin pigment is a neural
signal shown to assert dominance and signal
defensiveness
Egr-1 gene
Egr-1 gene
popular from the African Cichlid
important in synaptic plasticity (ability for
synapses to strengthen or weaken over time)
influences behavioral changes
allows ascending fish to become dominants if a
dominant leaves the area
What do deep sea fish lack? and Why?
bone because the water is cold and there is high
pressure so there is little need/room for
movement
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Why do deep sea fish have large mouths and/or
stomachs?
do not come across food often so when they do
they need to eat all of it to keep the energy
until they find more food (also the reason for
parasitic mating
phospholuminescent bacteria
used for mating and attracting prey
isolume
follows particular light intensity at a different
levels underwater
what is special about the isolume
certain fish follow the pattern of the isolume to
be able to evade nocturnal predators that prey
at the lower levels and see at the higher level
where the predators will be not active during
the night
palagic
open water
benthic
bottom dwelling
epipalagic
near surface (has the most biomass)
mesopalagic
middle (bottom of this layer has the last bit of
penetrable light)
Batypalagic
Deepest (no light reaches)
least amount of biomass
acanthopterygian
most common aquarium taxon
live in coral reef ecosystem
Why are small fish colorful in the coral reef
ecosystem?
They find shelter in the nooks of the reef which
larger fish cannot reach, they were able to
evolve colors for attracting mates
4 non-tetrapod Sarcopterygii
3 lungfish (dipnoi)
Australian
South American
African
1 is Actinista
Australian Lungfish
almost all gills
single lung in times of stress
south american lungfish
nothing known
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Document Summary
Largest clade of vertebrates two types of drag an organism experiences euteleosts. Tuna: no swim bladder, needs louder sounds to hear. Produce and care for relatively few young hatching from large eggs. Eggs are attached to some form of substrate. Hatchling (fry) develop forms and behaviors of adults quickly reproductive biology of marine teleosts. Hatchlings are larvae and look very different from adults until metamorphosis. African cichlid only one dominant male in the area and multiple subordinate males dominant is the only one who mates eye bar made of melanin pigment is a neural signal shown to assert dominance and signal defensiveness. Territorial male plainfin midshipman teleosts controls a group of rocks that are limited resources females value these rocks for spawning. What do deep sea fish lack? and why? bone because the water is cold and there is high pressure so there is little need/room for movement.
