1. Hearing, touch, taste, etc.

2. Sound transmission in water
water is 83x denser than air
sound travels 4.5x faster in water
- not rapidly attenuated; difficult to localize
low frequencies propagate better, faster

3. Sound transmission in water
water is 100x denser than air
sound travels 4.5x faster in water
- not rapidly attenuated; difficult to localize
low frequencies propagate better, faster
sound: small vibrations with particle displacement near source
- “near field” (a few meters)
sound pressure component – “far field”

4. Hearing and lateral line (acoustico-lateralis system)
Ears - sound reception in near field - acceleration, equilibrium
detects pressure waves
Lateral line – sound reception in far field - "distant touch"
detects particle displacement

5. Lateral line system superficial (free) neuromasts
on body surface, or in
shallow pits or grooves
canal neuromasts in lateral line
Perciformes, Centrarchidae: black crappie
Perciformes, Moronidae: white perch

6. superficial neuromast

7. canal neuromasts
superficial neuromast

8. Lateral line system
location and type of neuromasts optimized for particular
prey, environment, etc.
Cypriniformes, Cyprinidae: golden shiner

9. Science, 27 July 2012, p. 409

10. Ears equilibrium and balance:
three semicircular canals detect roll, yaw, pitch
also acceleration

11. (balance, acceleration)
Ears
equilibrium and balance:
three semicircular canals detect roll, yaw, pitch
also acceleration
semicircular canals
pars superior
(balance, acceleration)
utriculus
(lapillus)

12. (balance, acceleration)
Ears
sound reception
fish vibrates with sounds in water
otoliths vibrate slower, impinge on sensory cilia
semicircular canals
pars superior
(balance, acceleration)
utriculus
(lapillus)
lagena
(astericus)
pars inferior
(hearing)
sacculus
(sagitta)

14. Sagittal otolith
Left and right ears of a deep-sea cod.
Xiaohong Deng, Neuroscience and Cognitive Science Program, University of Maryland.

15. Ears
Otoliths

16. How can hearing sensitivity be improved?
Fish hearing is limited to lower frequency range, limited sensitivity to high frequencies
How can hearing sensitivity be improved?
Consider human hearing: normally transmitted from a drum (tympanum) via bones; or, artificially, directly from bone transmission

17. Ears hearing sensitivity improved with
1. Weberian apparatus – derived from vertebral bones
connects air bladder with ear labyrinth
present in ostariophysan fishes
(Cypriniformes, Characiformes, Siluriformes)
gives wide range of hearing ( Hz)

18. Ears hearing sensitivity improved with 1. Weberian apparatus
connects air bladder with ear labyrinth
present in ostariophysan fishes
gives wide range of hearing ( Hz)
2. direct connection of swim bladder and ear
squirrelfishes (Holocentridae)
herrings etc. (Clupeidae)

19. Ears hearing sensitivity improved with 1. Weberian apparatus
connects air bladder with ear labyrinth
present in ostariophysan fishes
gives wide range of hearing ( Hz)
2. direct connection of swim bladder and ear
3. airbreathers maintain bubble in superbranchial cavity,
near to ear

20. Sound production homepage.univie.ac.at/friedrich.ladich/Topics.htm
Web page link has fish sound recordings

21. Sound production stridulation due to friction - grinding of teeth
- movement of fin spine in socket, etc.
(catfish, triggerfish, filefish, sticklebacks)

22. Sound production stridulation due to friction - grinding of teeth
- movement of fin spine in socket, etc.
(catfish, triggerfish, filefish, sticklebacks)
via gas bladder
- release of air

23. Sound production stridulation due to friction - grinding of teeth
- movement of fin spine in socket, etc.
(catfish, triggerfish, filefish, sticklebacks)
via gas bladder
- release of air
- vibration of muscles (toadfishes, Batrachoididae;
searobins, Triglidae; drum, Sciaenidae)
Perciformes, Sciaenidae
– freshwater drum)

24. Sound production stridulation due to friction - grinding of teeth
- movement of fin spine in socket, etc.
(catfish, triggerfish, filefish, sticklebacks)
via gas bladder
- release of air
- vibration of muscles
incidental to other behaviors
- swimming and muscular motion
- breaking surface and splashing
- feeding, e.g., coral and crustacean-feeders
- production of bubbles

25. Sound production Problems associated with human sound production
boat motors
sonar
dredging, construction
naval activities

26. canoe < trolling motor < outboard time to recover:
Graham A L, Cooke S J The effects of noise disturbance from various recreational boating activities common to inland waters on the cardiac physiology of a freshwater fish, the largemouth bass (Micropterus salmoides) Aquatic Conservation - Marine And Freshwater Ecosystems 18:    
heart rate and stroke volume responded to canoe paddling, trolling motor, and outboard motor:
canoe < trolling motor < outboard
time to recover:
canoe ~15 min, trolling motor ~ 25 min, outboard ~ 40 min
concluded that boating activities can have ecological and environmental consequences

27. Taste and smell: communication
individual recognition, especially of mates
species recognition, esp. schooling species
offspring recognition (cichlids)
scent mark territories (gobies)
dominant-subordinate relationships
aggression-inhibiting pheromone produced by bullheads
living in groups

28. Olfaction (= chemoreception at "long" range/gradients)
more sensitive than taste
used for:
food finding
migration, e.g., salmon
intra, interspecific communication

29. Olfaction (= chemoreception at "long" range/gradients)
more sensitive than taste
used for:
food finding
migration, e.g., salmon
intra, interspecific communication
semiochemical – chemical used for communication
pheromone – elicits social response in same species
kairomone – benefits receiver, not emitter – between species
e.g., food, scent, necromone

30. Olfaction (= chemoreception at "long" range/gradients)
“Schreckstoff” alarm pheromones (Ostariophysi)

31. Olfaction (= chemoreception at "long" range/gradients)
“Schreckstoff” alarm pheromones (Ostariophysi)
originate in specialized ‘club’ cells in skin,
released when fish is damaged
effect is to alert other conspecifics
potent
highly specific (generally species-specific)
pass through gut of northern pike

32. Taste (= chemoreception at close range)
taste organs can reside on exterior surfaces:
barbels of bottom-dwelling fishes
lips of suckers
over much of body of ictalurids

33. Other cutaneous senses
touch
few detectors – shark fins; head, barbels of bullheads
mating behaviors (use of breeding tubercules)
parent-young communication in catfish, cichlids,
damselfishes

34. Other cutaneous senses
temperature
teleost cutaneous temp. sensitivity to 0.03C change
can distinguish rise from a fall in temperature
elasmobranchs detect temperature change with
ampullae of Lorenzini

35. Electrogeneration and electroreception
Why? Because they can (instantaneous transmission) – but note that pure water is an insulator
Because it’s useful (murky water)

36. Production of electricity
muscular contractions generate electrical signal
‘stack’ specialized cells (electrocytes) to amplify signal
(in series) with insulating material around them

37. Production of electricity
Types of electricity produced:
strong current - for stunning prey or escaping predators
10 to several hundred volts
in ‘volleys’ of discharges

38. Production of electricity
Types of electricity produced:
strong current - for stunning prey or escaping predators
weak current - for electrolocation
- conspecifics in school, - prey
emit continuous signal; objects entering field are
detected by distortion of field
discharge cycles/sec

39. Production of electricity
used by most elasmobranches, some teleosts
strong-electric fishes weak-electric fishes
Osteoglossiformes (Mormyridae)
- African electric fishes
Gymnotiformes (Gymnotidae) – electric eels
Torpediniformes (4 families)
– electric rays
(Gymnarchidae)
Perciformes (Uranoscopidae)
- stargazers
Siluriformes (Malapteruridae) - electric catfish
Rajiiformes (Rajiidae) – electric skates

40. Production of electricity
electricity-producing fishes tend to be
slow-moving, sedentary
active at night, or in murky water w. low visibility
have thick skin: good insulator
emhance signal-to-noise ratio with stiffened body

41. Electroreception types of signals received
movement through earth’s magnetic field
current from muscular activity of other fish (prey)
signals produced by conspecifics
frequency shifts identify individuals
Individuals change frequency when encountering conspecific so as not to mask signal

42. Electroreception detection via external pit organs
ampullae of Lorenzini in elasmobranches
open to surrounding water via canals, filled w. conductive gel
sensitive to
temperature change
mechanical and weak electrical stimuli
changes in salinity