Sensory Perception Vision Olfaction Hearing & mechanoreception Electroreception Magnetoreception.
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Transcript of Sensory Perception Vision Olfaction Hearing & mechanoreception Electroreception Magnetoreception.
Sensory Perception
VisionOlfactionHearing & mechanoreceptionElectroreceptionMagnetoreception
Senses
Physical Quantity
Sense Organ
Sound Ears
Water flow Lateral line
Chemicals Taste Buds/Nose
Electricity Ampullae of Lorenzini
Magnetic Fields Nose ????
Light Eyes
Acoustico – Lateralis System
Hair sensory cells
•Equilibrium•Hearing•Mechanoreception
Sensory Hair Cells
Hearing in Fishes
• Fish have ears• Otoliths detect
particle motion• Swimbladder can
act as pressure transducer
What is Sound?
• Sound is a mechanical vibration that propagates through an elastic medium such as air or water.
• Sound travels as waves of oscillating particles accompanied by increases and decreases in the ambient pressure.
• Sound propagates along the axis of particle vibration.
Compression
Rarefaction
No Sound
Speaker
Ear Morphology
Fish hearing is generally low-frequency
Cyprinidae
American Shad Audiogram
Ultrasonic detection by american shad. Classical Conditioning: Example of cardiac response followed by electric shock
Ultrasonic sound detection by American Shad
Auditory Brain Response
Swimbladder of the toadfish, Opsanus sp. Sonic muscles can be seen on the lateral walls.
BatrachoididaeOyster toadfishOpsanus tau
Sound Production
Ecology of Sound Production
Time
Fre
qu
en
cy
18:00 19:00 20:00 21:00 22:00 23:00 24:00 01:00 02:00 03:000
2000
4000
6000
8000
10000
12000
Sound produced by spawning aggregation of sciaenids
Lateral LineNeuromasts: groups of hair cell w/gelatinous cupule
Hydrodynamic Stimuli
• Water currents from flows (rheotaxis)
•Schooling/predator avoidance
•Active hydrodynamic imaging
•Passive hydrodynamic imaging
•Courtship
•Subsurface feeding
Flows produced by organisms
Lateral line shapes
Electroreception
ElasmobranchsTeleostsLow frecuency AC - DC
TeleostsHigh frequency AC
Electroreceptors
Ampullae de Lorenzini
Dogfish can detect a flounder buried 15 cm deep (1 mV/Km)
Electrical fishes
Electric Organ Discharge (EOD)• Modified muscle cells to create EOD
Brachyhypopomus spp. EOD
Magnetoreception
• Elasmobranchs– Hammerhead shark schools– Laboratory experiments with rays
• Teleosts– Magnetite found in Salmon and Tuna
Magnetoreception
Induced Electric Field•Currents in ocean flowing through earth’s magnetic field generate currents from <5 nV/cm to 500 nV/cm.
•Suspected that eels use these currents, but not clear if they are sensitive enough to electrical fields.
•Stingrays can sense fields as low as 5 nV.cm
At ambient magnetic field of 0.5 gauss, a swimming speed of 1 cm/s would produce a threshold stimulus of 5 nV/cm.This has yet to be proven.
Magnetite in Nose (Trout)a. Bacteria containing magnetite (not
from the trout).
b. Olfactory epithelium. Red dot with arrow is putative magnetite.
c. Bright field (left) and dark field (right) TEM of dot from b.
d. Energy dispersive analysis of x-rays from crystal. Shows presence of iron (Cu is from copper screen, Pb and U from TEM stains).
Walker, Diebel, Haugh, Pankhurst, Montgomery, & Green. 1997. Structure and function of the vertebrate magnetic sense. Nature. 390: 371-376.
Olfaction
Taste Buds
Vision
Photoreceptor cells
• Rods– Sensitive at low light levels– Present in all fishes
• Cones– Sensitive at high light intensity– Some elasmobranchs and most fishes
Red cones (600nm)Green cones (530nm)Blue cones (460nm)Ultraviolet cones (380nm)
Electromagnetic Wavelengths
Rod maximum absorption
Visual AcuityDetermined by eye aperture and photoreceptor density.
Acuity increases as size increases.