329
0.05 0.1
0.3 0.5
1
2 3 5
Hearing threshold (dB re 1 µPa)
60
80
100
120
bony encapsulated s.bl.
free unpaired s.bl.
a
Frequency (kHz)
0.05 0.1
0.3 0.5
1
2 3 5
Hearing threshold (dB re 1 µPa)
60
80
100
120
*
**
**
**
**
b
bony encapsulated s.bl.
free unpaired s.bl.
Fig. 5 ( a ) Mean AEP
thresholds of six catfi sh
species with free, large
unpaired swim bladders
( solid lines ) and of fi ve
species with encapsulated,
tiny, and paired swim
bladders ( dashed lines ). ( b )
Mean hearing thresholds of
all species with free swim
bladders and paired
encapsulated bladders.
Asterisks indicate
statistically signifi cant
differences between these
two groups at particular
frequencies. Modifi ed from
Lechner and Ladich ( 2008 )
b
smaller swim bladder
a
larger swim bladder
Fig. 6 Schematic
relationship between swim
bladders within thorny
catfi shes. ( a ) Species with
larger swim bladders and
( b ) species with smaller
swim bladders. Note that
bladders are always
unpaired and
unencapsulated, in contrast
to those in Fig. 2b
Peripheral Hearing Structures in Fishes: Diversity and Sensitivity…