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).