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© Springer International Publishing Switzerland 2016
J.A. Sisneros (ed.), Fish Hearing and Bioacoustics, Advances in Experimental
Medicine and Biology 877, DOI 10.1007/978-3-319-21059-9_15
Peripheral Hearing Structures in Fishes:
Diversity and Sensitivity of Catfi shes
and Cichlids
Friedrich Ladich
Abstract Fishes have evolved an astonishing diversity of peripheral (accessory/
ancillary) auditory structures to improve hearing based on their ability to transmit
oscillations of gas bladder walls to the inner ears. So far it is unclear to what degree
the size of the bladder and the linkage to the ear affect hearing in fi shes. An interfamilial study in catfi shes revealed that families which possess large, single swim
bladders and one to four Weberian ossicles were more sensitive at higher frequencies (≥1 kHz) than families which have small, paired, and encapsulated bladders
and one to two ossicles. An intrafamilial investigation in thorny catfi shes (family
Doradidae) revealed that small differences in bladder morphology did not affect
hearing similarly. Members of the cichlid family possess an even larger variation in
peripheral auditory structures than catfi shes. The linkage between the swim bladder
and ear can either be present via anterior extensions of the bladder or be completely
absent (in contrast to catfi shes). Representatives having large bladders with extensions had the best sensitivities. Cichlids lacking extensions had lower sensitivities
above 0.3 kHz. Species with a vestigial swim bladder exhibited a smaller hearing
bandwidth than those with larger swim bladder (maximum frequency: 0.7 kHz vs. 3
kHz). Catfi shes and cichlids reveal that larger gas bladders and more pronounced
connections between the swim bladder and the inner ear result in improved hearing
at higher frequencies. The lack of a connection between a large bladder and the
inner ear does not necessarily result in a smaller detectable frequency range.
Keywords Swim bladder morphology • Auditory ossicles • Audiograms • Auditory
sensitivity • AEP
F. Ladich (*)
Department of Behavioural Biology , University of Vienna ,
Althanstrasse 14 , 1090 Vienna , Austria
e-mail: friedrich.ladich@univie.ac.at
© Springer International Publishing Switzerland 2016
J.A. Sisneros (ed.), Fish Hearing and Bioacoustics, Advances in Experimental
Medicine and Biology 877, DOI 10.1007/978-3-319-21059-9_15
Peripheral Hearing Structures in Fishes:
Diversity and Sensitivity of Catfi shes
and Cichlids
Friedrich Ladich
Abstract Fishes have evolved an astonishing diversity of peripheral (accessory/
ancillary) auditory structures to improve hearing based on their ability to transmit
oscillations of gas bladder walls to the inner ears. So far it is unclear to what degree
the size of the bladder and the linkage to the ear affect hearing in fi shes. An interfamilial study in catfi shes revealed that families which possess large, single swim
bladders and one to four Weberian ossicles were more sensitive at higher frequencies (≥1 kHz) than families which have small, paired, and encapsulated bladders
and one to two ossicles. An intrafamilial investigation in thorny catfi shes (family
Doradidae) revealed that small differences in bladder morphology did not affect
hearing similarly. Members of the cichlid family possess an even larger variation in
peripheral auditory structures than catfi shes. The linkage between the swim bladder
and ear can either be present via anterior extensions of the bladder or be completely
absent (in contrast to catfi shes). Representatives having large bladders with extensions had the best sensitivities. Cichlids lacking extensions had lower sensitivities
above 0.3 kHz. Species with a vestigial swim bladder exhibited a smaller hearing
bandwidth than those with larger swim bladder (maximum frequency: 0.7 kHz vs. 3
kHz). Catfi shes and cichlids reveal that larger gas bladders and more pronounced
connections between the swim bladder and the inner ear result in improved hearing
at higher frequencies. The lack of a connection between a large bladder and the
inner ear does not necessarily result in a smaller detectable frequency range.
Keywords Swim bladder morphology • Auditory ossicles • Audiograms • Auditory
sensitivity • AEP
F. Ladich (*)
Department of Behavioural Biology , University of Vienna ,
Althanstrasse 14 , 1090 Vienna , Austria
e-mail: friedrich.ladich@univie.ac.at