301
greater ontogenetic change. Additional studies looking at how other morphological
changes relate to ontogenetic changes in auditory sensitivity would greatly improve
our understanding of the structure function relationships between auditory structures and hearing sensitivity in fi shes.
3 Development of Hearing in Fishes
In contrast to other vertebrate groups, there are only a few studies that have examined the development of hearing capabilities in fi sh. Most ontogenetic studies of fi sh
hearing have focused on changes in auditory sensitivity in regard to thresholds of
auditory evoked potentials (AEPs) across different-sized animals, although a few
studies measured other functions such as changes in temporal encoding with age/
size (e.g., Sisneros and Bass 2005 ).
Depending on the specifi c research question and species of fi sh examined, there
has been a large degree of variability in the developmental stages investigated.
While some studies tried to understand the functional role of specifi c morphological
structures for hearing enhancement (e.g. Lechner et al. 2011 ; Webb et al. 2012 ;
Caiger et al. 2013 ) or even the relationship between auditory sensitivity and the
onset of vocal communication (e.g. Wysocki and Ladich 2001 ; Vasconcelos and
Ladich 2008 ) over a wide range of fi sh sizes, others have only focused on larval
stages to determine whether the auditory system is developmentally functional to
enable fi sh larvae to fi nd specifi c habitats for settlement using environmental acoustic cues (Wright et al. 2011 ).
This section provides a systematic overview of the studies concerning the development of fi sh hearing during ontogeny organized by taxa. Moreover, a fi nal part
will focus on how the hearing sense in fi shes has evolved for the enhancement of
social acoustic communication.
3.1 Diversity of Auditory Sensitivity
In order to study the development of auditory sensitivity in juvenile fi sh, investigators have employed different methods for the assessment of hearing ranging from
behavioral to electrophysiological approaches. Likely due to the long training periods and diffi culty of training small juvenile fi sh, only one study has used a behavioral conditioning method to investigate the ontogenetic development of auditory
sensitivity (Kenyon 1996 ). One behavioral technique that has proved useful in
determining whether or not the auditory system is functional during development is
the acoustic startle or startle-like escape responses that consist of a stereotyped
“tail-fl ip” response evoked by relatively loud sound stimuli (Blaxtey and Batty
1985 ; Fuiman et al. 1999 ; Zeddies and Fay 2005 ; Alderks and Sisneros 2013 ).
Development of Structure and Sensitivity of the Fish Inner Ear
greater ontogenetic change. Additional studies looking at how other morphological
changes relate to ontogenetic changes in auditory sensitivity would greatly improve
our understanding of the structure function relationships between auditory structures and hearing sensitivity in fi shes.
3 Development of Hearing in Fishes
In contrast to other vertebrate groups, there are only a few studies that have examined the development of hearing capabilities in fi sh. Most ontogenetic studies of fi sh
hearing have focused on changes in auditory sensitivity in regard to thresholds of
auditory evoked potentials (AEPs) across different-sized animals, although a few
studies measured other functions such as changes in temporal encoding with age/
size (e.g., Sisneros and Bass 2005 ).
Depending on the specifi c research question and species of fi sh examined, there
has been a large degree of variability in the developmental stages investigated.
While some studies tried to understand the functional role of specifi c morphological
structures for hearing enhancement (e.g. Lechner et al. 2011 ; Webb et al. 2012 ;
Caiger et al. 2013 ) or even the relationship between auditory sensitivity and the
onset of vocal communication (e.g. Wysocki and Ladich 2001 ; Vasconcelos and
Ladich 2008 ) over a wide range of fi sh sizes, others have only focused on larval
stages to determine whether the auditory system is developmentally functional to
enable fi sh larvae to fi nd specifi c habitats for settlement using environmental acoustic cues (Wright et al. 2011 ).
This section provides a systematic overview of the studies concerning the development of fi sh hearing during ontogeny organized by taxa. Moreover, a fi nal part
will focus on how the hearing sense in fi shes has evolved for the enhancement of
social acoustic communication.
3.1 Diversity of Auditory Sensitivity
In order to study the development of auditory sensitivity in juvenile fi sh, investigators have employed different methods for the assessment of hearing ranging from
behavioral to electrophysiological approaches. Likely due to the long training periods and diffi culty of training small juvenile fi sh, only one study has used a behavioral conditioning method to investigate the ontogenetic development of auditory
sensitivity (Kenyon 1996 ). One behavioral technique that has proved useful in
determining whether or not the auditory system is functional during development is
the acoustic startle or startle-like escape responses that consist of a stereotyped
“tail-fl ip” response evoked by relatively loud sound stimuli (Blaxtey and Batty
1985 ; Fuiman et al. 1999 ; Zeddies and Fay 2005 ; Alderks and Sisneros 2013 ).
Development of Structure and Sensitivity of the Fish Inner Ear