292
1 Introduction
Studies on the auditory system have provided an unmatched wealth of information
related to the evolution and function of sensory systems in vertebrates. The comparative data obtained from different levels of the auditory system, from the peripheral to the central auditory system, is by far the richest among all sensory systems.
However, despite our growing knowledge in auditory system neuroscience, there
are a number of fundamental questions related to the development and function of
auditory structures that remain poorly understood across vertebrate taxa. For example, how does auditory reception and its neural processing change during ontogeny?
Which morphological changes occur in the inner ear versus the central auditory
system that may account for developmental improvements in hearing? What is the
relationship between auditory development and vocal differentiation? Although
some effort has been made to answer these questions in comparative studies from
birds and mammals, the available information is scarce and in need of further investigation that includes also lower vertebrates such as fi sh. Such a research perspective will be needed in order to gain fundamental comparative insights into the
evolution and ecology of the vertebrate auditory system.
The diversity of structure and function of fi sh sensory systems is exceptional,
suggesting that through evolution species have found ways to become more adapted
to their highly diverse aquatic environments. This diversity is particularly evident in
the octavolateralis system of fi shes that includes the lateral line and the inner ear
(Braun and Grande 2008 ).
Fishes rely on their auditory system to extract biologically relevant information
from the auditory scene, such as the presence of conspecifi cs, predators, prey, and
to detect abiotic elements for orientation. The capacity to detect acoustic signals in
the soundscape seems to start early in life in most species. Besides being important
for the detection of food or danger, the auditory sense in juvenile fi sh is also important for intraspecifi c acoustic communication during agonistic interactions in the
context of competition over food or space (Schneider 1964 ; Henglmüller and Ladich
1999 ; Amorim and Hawkins 2005 ; Kéver et al. 2012 ).
Studies that examine the ontogeny of hearing in fi shes can ultimately provide an
evolutionary perspective and deeper understanding of the mechanisms underlying
the development of the auditory sense in all vertebrates. Many of the early developmental events in fi shes appear to be evolutionarily conserved across all vertebrate
groups in spite of the large diversity in auditory structure found in adult animals
(Retzius 1884 ; Baird 1974 ; Henson 1974 ).
In this chapter we review the available information on the ontogenetic development of the inner ear morphology and sensitivity in fi sh. In addition, we briefl y
describe the available information on the development of auditory capabilities for
social acoustic communication in this taxon, another area of research where information is still fairly limited.
R.O. Vasconcelos et al.
1 Introduction
Studies on the auditory system have provided an unmatched wealth of information
related to the evolution and function of sensory systems in vertebrates. The comparative data obtained from different levels of the auditory system, from the peripheral to the central auditory system, is by far the richest among all sensory systems.
However, despite our growing knowledge in auditory system neuroscience, there
are a number of fundamental questions related to the development and function of
auditory structures that remain poorly understood across vertebrate taxa. For example, how does auditory reception and its neural processing change during ontogeny?
Which morphological changes occur in the inner ear versus the central auditory
system that may account for developmental improvements in hearing? What is the
relationship between auditory development and vocal differentiation? Although
some effort has been made to answer these questions in comparative studies from
birds and mammals, the available information is scarce and in need of further investigation that includes also lower vertebrates such as fi sh. Such a research perspective will be needed in order to gain fundamental comparative insights into the
evolution and ecology of the vertebrate auditory system.
The diversity of structure and function of fi sh sensory systems is exceptional,
suggesting that through evolution species have found ways to become more adapted
to their highly diverse aquatic environments. This diversity is particularly evident in
the octavolateralis system of fi shes that includes the lateral line and the inner ear
(Braun and Grande 2008 ).
Fishes rely on their auditory system to extract biologically relevant information
from the auditory scene, such as the presence of conspecifi cs, predators, prey, and
to detect abiotic elements for orientation. The capacity to detect acoustic signals in
the soundscape seems to start early in life in most species. Besides being important
for the detection of food or danger, the auditory sense in juvenile fi sh is also important for intraspecifi c acoustic communication during agonistic interactions in the
context of competition over food or space (Schneider 1964 ; Henglmüller and Ladich
1999 ; Amorim and Hawkins 2005 ; Kéver et al. 2012 ).
Studies that examine the ontogeny of hearing in fi shes can ultimately provide an
evolutionary perspective and deeper understanding of the mechanisms underlying
the development of the auditory sense in all vertebrates. Many of the early developmental events in fi shes appear to be evolutionarily conserved across all vertebrate
groups in spite of the large diversity in auditory structure found in adult animals
(Retzius 1884 ; Baird 1974 ; Henson 1974 ).
In this chapter we review the available information on the ontogenetic development of the inner ear morphology and sensitivity in fi sh. In addition, we briefl y
describe the available information on the development of auditory capabilities for
social acoustic communication in this taxon, another area of research where information is still fairly limited.
R.O. Vasconcelos et al.