Vol. 53, 2014
The auditory roles of the gas bladder and suprabranchial
chamber in walking catfish (Clarias
Ta Shao1,2, I-Shiung Chen2 and Hong Young Yan1,3*
1Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, 23-10, Dawen Road, Jiaoshi 26242, Taiwan
2Institute of Marine Biology, National Taiwan Ocean University, Keelung 20224, Taiwan
3Hanse-Wissenschaftskolleg Institute for Advanced Study, Lehmkuhlenbusch 4, Delmenhorst 27753, Germany
Background: The enhanced auditory
abilities of certain fish are dependent on specialized hearing
structures. Several gas-holding structures, including the
suprabranchial chamber, otic gas bladder, and Weberian apparatus-linked
gas bladder, have been demonstrated to improve the hearing ability of
fish. The walking catfish (Clarias
batrachus), a benthic species, is unique in that it has both a
suprabranchial chamber (SC) and a Weberian apparatus-linked,
encapsulated gas bladder (WGB). This study aimed to investigate the
respective roles of these two structures in contributing to the overall
hearing ability of walking catfish.
Results: The auditory evoked potentials method was
used to measure hearing thresholds in intact fish and fish with a
deflated WGB and/or SC. Gas removal from the WGB increased auditory
thresholds at all frequencies tested (0.4 to 5.0 kHz), whereas
injection of water into the SC shifted the threshold only at
frequencies below 3.0 kHz. However, such a correlation was not observed
for the SC at 4.0 and 5.0 kHz.
Conclusions: The findings indicated
that both the encapsulated WGB and the SC had an accessory auditory
role. However, WGB enhanced hearing abilities in the whole frequency
range, whereas SC did not.
Key words: Hearing ability; AEP; Catfish;
Weberian apparatus; Suprabranchial chamber.
*Correspondence: E-mail: email@example.com