371
ties to the lagena in otophysans (Popper and Platt 1983 ). So far, no data about the
hearing abilities of anotophysans are available (Fay 1988 ; Ladich and Fay 2013 ).
2.3.3 Euteleostomorpha
Euteleostomorpha comprise numerous teleost orders that show considerable diversity in gross inner ear morphology. In Gobiiformes (Fig. 1c ; Fig. 6d ) and
Batrachoidiformes the saccule is much larger than the other two otolithic end organs
and the semicircular canals run around the saccule rather than being located dorsally to it. Cyprinodontiform fi shes (e.g., poeciliids) (Fig. 1b ) and Oryzias latipes
(Beloniformes) possess a utricle that is directly connected to the anterior portion of
the saccule (Froese 1938 ; Noro et al. 2007 ; Schulz-Mirbach et al. 2011 ), whereas in
most other bony fi shes the utricle is located anterodorsally to the saccule. Further
gross morphological variation is found in sea horses (Syngnathidae,
Syngnathiformes). They have “compact” ears with almost rectangular instead of
rounded semicircular canals (Retzius 1881 ). Moreover, several unrelated species of
fl ying fi shes ( Dactylopterus volitans , Dactylopteridae, Syngnathiformes; Exocoetus
volitans , Beloniformes) show distinctly large semicircular canals and extremely
small otolithic end organs (Retzius 1881 ; Froese 1938 ). Large semicircular canals
are also present in Lophius piscatorius (Lophiiformes) and Eutrigla gurnardus
(Perciformes; Fig. 1e ) (Retzius 1881 ). The functional meaning of these enlarged
semicircular canals remains to be studied.
Among the euteleostomorph fi shes, several groups include deep-sea fi shes like
the Myctophidae (Myctophiformes), Bregmacerotidae, Macrouridae, Moridae, and
Gadidae (all four families belong to the Gadiformes), Melamphaidae (Beryciformes),
Opisthoproctidae
(Argentiniformes),
Gonostomatidae
(Stomaitiformes),
Melanocetidae (Lophiiformes), or Holocentridae (Holocentriformes). Ears of deepsea fi shes show some of the most remarkable modifi cations, especially with respect
to the maculae (Popper 1977 , 1980 ; Deng 2009 ; Deng et al. 2011 , 2013 ). Several
species are marked by distinctly long ciliary bundles (Melamphaidae; Antimora
rostrata , Moridae) (Deng et al. 2011 , 2013 ), special fi elds of supporting cells
(Melamphaidae; Myctophidae; Opistoproctus soleatus ; Gonostomus elongatum ;
Melanocetus johnsonii ; Myripristis , Holocentridae) (Popper 1977 , 1980 ; Deng
et al. 2011 , 2013 ) (Fig. 5c ) and complex orientation patterns on the macula sacculi
(e.g., Antimora rostrata ; Myripristis ) (Fig. 5b, c ). Some species also possess anterior swim bladder extensions, for example Antimora rostrata and species of the
genus Myripristis (Nelson 1955 ; Deng et al. 2011 ). Except for the improved hearing
in several reef-associated holocentrids such as Sargocentron xantherythrum (formerly Adioryx xantherythrus ) and Myripristis kuntee (Coombs and Popper 1979 ;
see overviews in Hawkins 1993 and Ladich, this volume), the effects of these inner
ear modifi cations are unknown because auditory abilities of deep-sea fi shes cannot
be measured under lab conditions. It is assumed that long ciliary bundles enhance
the ability to detect the low frequencies that probably play a certain role in the deepsea; improvements of the vestibular sense and adaptations to the high water presDiversity of Inner Ears in Fishes: Possible Contribution Towards Hearing…
ties to the lagena in otophysans (Popper and Platt 1983 ). So far, no data about the
hearing abilities of anotophysans are available (Fay 1988 ; Ladich and Fay 2013 ).
2.3.3 Euteleostomorpha
Euteleostomorpha comprise numerous teleost orders that show considerable diversity in gross inner ear morphology. In Gobiiformes (Fig. 1c ; Fig. 6d ) and
Batrachoidiformes the saccule is much larger than the other two otolithic end organs
and the semicircular canals run around the saccule rather than being located dorsally to it. Cyprinodontiform fi shes (e.g., poeciliids) (Fig. 1b ) and Oryzias latipes
(Beloniformes) possess a utricle that is directly connected to the anterior portion of
the saccule (Froese 1938 ; Noro et al. 2007 ; Schulz-Mirbach et al. 2011 ), whereas in
most other bony fi shes the utricle is located anterodorsally to the saccule. Further
gross morphological variation is found in sea horses (Syngnathidae,
Syngnathiformes). They have “compact” ears with almost rectangular instead of
rounded semicircular canals (Retzius 1881 ). Moreover, several unrelated species of
fl ying fi shes ( Dactylopterus volitans , Dactylopteridae, Syngnathiformes; Exocoetus
volitans , Beloniformes) show distinctly large semicircular canals and extremely
small otolithic end organs (Retzius 1881 ; Froese 1938 ). Large semicircular canals
are also present in Lophius piscatorius (Lophiiformes) and Eutrigla gurnardus
(Perciformes; Fig. 1e ) (Retzius 1881 ). The functional meaning of these enlarged
semicircular canals remains to be studied.
Among the euteleostomorph fi shes, several groups include deep-sea fi shes like
the Myctophidae (Myctophiformes), Bregmacerotidae, Macrouridae, Moridae, and
Gadidae (all four families belong to the Gadiformes), Melamphaidae (Beryciformes),
Opisthoproctidae
(Argentiniformes),
Gonostomatidae
(Stomaitiformes),
Melanocetidae (Lophiiformes), or Holocentridae (Holocentriformes). Ears of deepsea fi shes show some of the most remarkable modifi cations, especially with respect
to the maculae (Popper 1977 , 1980 ; Deng 2009 ; Deng et al. 2011 , 2013 ). Several
species are marked by distinctly long ciliary bundles (Melamphaidae; Antimora
rostrata , Moridae) (Deng et al. 2011 , 2013 ), special fi elds of supporting cells
(Melamphaidae; Myctophidae; Opistoproctus soleatus ; Gonostomus elongatum ;
Melanocetus johnsonii ; Myripristis , Holocentridae) (Popper 1977 , 1980 ; Deng
et al. 2011 , 2013 ) (Fig. 5c ) and complex orientation patterns on the macula sacculi
(e.g., Antimora rostrata ; Myripristis ) (Fig. 5b, c ). Some species also possess anterior swim bladder extensions, for example Antimora rostrata and species of the
genus Myripristis (Nelson 1955 ; Deng et al. 2011 ). Except for the improved hearing
in several reef-associated holocentrids such as Sargocentron xantherythrum (formerly Adioryx xantherythrus ) and Myripristis kuntee (Coombs and Popper 1979 ;
see overviews in Hawkins 1993 and Ladich, this volume), the effects of these inner
ear modifi cations are unknown because auditory abilities of deep-sea fi shes cannot
be measured under lab conditions. It is assumed that long ciliary bundles enhance
the ability to detect the low frequencies that probably play a certain role in the deepsea; improvements of the vestibular sense and adaptations to the high water presDiversity of Inner Ears in Fishes: Possible Contribution Towards Hearing…