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Week 9: Sensory Systems
mechanical
mechanicalexternal stimulus
behavior
mechanosensory systems
environmental linkhighly selective
external stimulus
(filtered)
energytransduction
electric signal
sensory neuron
electrical currentinside the neuron
membrane potential, Vm = outside (0 mV) to inside (– mV) = electrical difference = resistance
Vm
stimulus
electrochemical componentacross the membrane
stimulus
resting (-) up-spike (++) down-spike (- -) reset (-)
= Electrical
Auditory
= Gustatory
smell
sight electric
movementhearing
taste
visual chemicalmechanicalelectrical
mechanosensory organs
lateral line
inner ear
cilia
~ gelatin, mucous
mechanoreceptor cellswith cilia
=neuromasts
=hair cells
= displaces cilia
inhibits (-) excites (+)
sensitive to:velocity pressureparticle movement (displacement)
all editions
inhibits (-) excites (+)
all editions
mechanoreceptory organs
lateral line
inner ear
density differencesair: water
vertebrate ear
= displaces cilia
inhibits (-) excites (+)
sensitive to:velocity pressureparticle movement (displacement)
all editions
mechanical displacement
cypriniformperciform
xzy
3 otolithic organs
3 semicircular canals
3 semicircular canals
x, y, z
Antimora sp. flat nose codMoridae, Gadiformes
lamprey ~ 2hagfish ~ 1
3 otolithic organs
lagena
sacculus
utriculus
x-axis canal
z-axis canaly-axis canal
DORSAL (pars superior)
balance~ equilibrium
~ gravity
3 semicircular canals
3 semicircular canals (labyrinths)~ 3 planes: x, y, z
x: pitch up/down
y: yawside/side
z: rollhead/tail
z-axis canallongitudinal
x-axis horizontal
y-axis vertical
head deviations from...
yxz
3 otolithic organs
3 semicircular canals
Antimora sp. flat nose codMoridae, Gadiformes
3 otolithic organs
blue gourami
3 otolithic organs
utriculus
lagena
sacculus
otolith
otolithic organs
mineralized depositdenser ~2nd data point
sacculus contains sagitta
Cb = cilia bundleOM = otolithic membrane
lagena
sacculus
utriculus
DORSAL (pars superior)
balance~ equilibrium
~ gravity
Ventral (pars inferior)
sound
utriculus lagena
sacculus
otolith (largest)
Water Air
800 x density
least (0°C) expandsmost (4°C) contractssolid, liquid, gas
Absorbs more energy (light, radiation, heat)Holds more energy (light, radiation, heat)Dissolves more molecules (nutrients, toxins)
Conducts more energy (sound, electricity) farther~5 x faster
(according to T, P, salinity)
Aquatic Habitats
Sound fields: near far
crenulated, nondivergent smooth, spherical…
particle displacement pressure wave
intensity (decibels, dB)vs. range (length)
vibration compression
volume/pressure
yxz
ventral otolithic organs detect near-field particle displacement
yxz
gas bladder detects far-field pressure wave
Sound fields: near far
crenulated, nondivergent smooth, spherical…
particle displacement pressure wave
intensity (decibels, dB)vs. range (length)
Detector: inner ear gas bladder
pike perch
carp herring
gas bladders = acoustically transform far field pressure wave to near-field particle displacement
African knifefish (Osteoglossomorpha)
gas bladder throughout body
Weberian ossicles
gas bladder
inner ear
xzy
acoustically transform far field pressure wave
vibrates in response to far-field pressure waves
no gas bladder
no mineralization
sand grains for near field
dorsal tympanic membrane for far field
~near field:low frequency10 to 600 Hz
Chondrichthyes
Sound fields: near far
particle displacement pressure wave
Detector: inner ear gas bladder
low frequency: long wavelengthlarge near field ~~~~~~~~~~~~~~~~~~))))))
high frequency: short wavelengthlarge far field ~~~~~~)))))))))))))))))))))))))
Sound type:
goldfish (O)salmon (Pr)cod (Pa)damselfish (Ac)= Stegastestuna (Ac)
herring (100,000+)~bottlenose dolphin
low: larger near field high: larger far fieldfavors inner ear favors gas bladder
pike perch
carp herring
herring
American shad
gas-filled bulla
Week 9:
Activities
Biology of Fishes/Spring 2010 Week 9 Sensory Activity 1
Give examples of fishes (especially those we have covered to date) that illustrate the following sensory modes in interesting ways. Use a variety of methods (Aquarium Activities, Outline of Fish Groups handout, text chapter 14 on, or the NEAq census) to make sure all interesting fishes are included. List or organize the fishes phylogenetically. Add to your list during lecture...
Visual (light and luminescence)
Chemical (taste and smell)
Mechanical (pressure and sound)
Electrical (electromagnetic fields)
Biology of Fishes/Spring 2010 Week 9 Sensory Activity 2
A. For the schematic below, label the structures as described (italicized):
1. Dorsal and Ventral regions of ear
2. Regions for Sound detection and Balance detection
3. Regions for Equilibrium and Particle displacement
4. Location of sound chambers, lagena (small) and sacculus (large) and respective otoliths
5. Location of balance chamber, utriculus and otolith
6. Semicircular canals for x-axis (horizontal), y-axis (vertical), and z-axis (lateral).