Department of Biology
Western Kentucky University.
Bowling Green, KY 42101
(270) 745-2405 (w) (270) 745-6856 (fax)
My primary research interest is the sensory biology of fish
hearing. Projects in my lab examine the teleost auditory
system in biomedical, environmental, and ecological/evolutionary
The auditory sensory cells of fishes are called hair cells.
These cells are similar in form and function to mammalian hair
cells, but while mammalian hair cells that are damaged as a
result of loud sounds or ototoxic chemicals are not replaced,
deafened fish have the capability to regenerate hair cells
and recover their hearing. I am studying the process of hair
cell death and regeneration following acoustic trauma in goldfish
and zebrafish. Such baseline data is needed to begin to understand
how hair cell regeneration occurs in fish and why such regeneration
does not occur in mammals. Recently, hair cell development
has been shown to be regulated by specific genes (e.g., Atoh1,
Rb1, and p27Kip1) in the mammalian auditory system and manipulating
gene expression can result in hair cell regeneration. I am
examining the natural expression of these genes in fish ears
that are undergoing hair cell regeneration.
High levels of sound are known to have significant effects
on the auditory system and overall physiology of humans and
other animals. Although there has been recent concern about
the effects of anthropogenic sounds, such as those produced
by Navy sonar or seismic surveys, on marine mammals, little
is known about how such intense underwater sounds affect other
marine life such as fishes. Some of my projects focus on how
loud sounds damage the ears and hearing capabilities of fishes
(Please see "Effects of Intense Sound on the Ear of Fishes").
I examine damage to the hair cells of fish ears using scanning
electron microscopy (SEM) and the effect on fish hearing using
electrophysiological methods (auditory brainstem response).
Loud continuous sounds can cause temporary hearing loss in
fishes, with the extent of hearing loss increasing with noise
exposure duration and intensity, and recovery of hearing occurring
within a few days or weeks. The extent of hearing loss is also
species specific- fishes with more sensitive hearing thresholds
are more prone to hearing loss, whereas non-sensitive fish
are barely affected. The latter was shown in a long term-study
on the effects of aquaculture noise in rainbow trout. I have
proposed a model termed the Linear Threshold Shift Hypothesis
(LINTS) to predict the extent of noise-induced hearing loss
in fishes, and this model should be beneficial in mitigating
the effects of anthropogenic sound on fishes. Other effects
of noise include acoustical masking and physiological and behavioral
stress responses, which also depend on species and noise type.
It is generally agreed that the sense of vertebrate hearing first evolved in
fishes. Fishes are the most speciose of the vertebrates and exhibit a diverse
range of form, function, and ecological niches. Thus they provide a wonderful
opportunity to study the evolution of hearing. I am currently examining a family
of catfishes (Loricariidae) that have a unique bi-lobed swim bladder and holes
in their skull adjacent to their swim bladder. These catfishes also produce
sounds by stridulating their pectoral fins and I am interested in understanding
the behavioral context of these sounds. My goal is to understand the acoustical
significance (in terms of hearing and/or sound production) and evolution of
these unique structures.
A.N., M.E. Smith, P.A. Cott, B.W. Hanna, A.O. MacGillivray,
M.E. Austin, and D.A. Mann.
2005. Effects of exposure to seismic airgun use on hearing
of three fish species. Journal of the Acoustical Society
of America 117(6):3958-3971.
A.N., Halvorsen, M.B., Miller, D.L., Smith, M.E., Song,
J., Wysocki, L.E.,
Hastings, M.C., Kane, A.S., and Stein, P.
2005. Effects of surveillance towed array sensor system
(SURTASS) low frequency active sonar on fish. Journal
of the Acoustical
Society of America 117(4):2440.
L.A., Cowan, J.H., Jr., Smith, M.E., and O’Neal,
J.P. 2005. Behavior and recruitment success in fish
larvae: variation with growth rate and the batch effect.
Journal of Fisheries and Aquatic Sciences 62:`1337-1349.
M.C., Johnson, J.B., Wilson, K.W., Smith, M.E., and Houston,
D.D. 2005. Variation in intrinsic individual
growth rate among
populations of leatherside chub (Snyderichthys copei
Jordan & Gilbert):
adaptation to temperature or length of the growing
season? Ecology of Freshwater Fishes 14(2):177-184.
M.E., Kane, A.S., and Popper, A.N. 2004. Acoustical
stress and hearing sensitivity in fishes: does
the linear threshold shift hypothesis hold water? Journal
M.E., Kane, A.S., and Popper, A.N. 2004. Noise-induced
stress response and hearing loss
in goldfish (Carassius
auratus). Journal of Experimental Biology 207(3):427-435.
A. N., Fewtrell, J., Smith, M. E. and McCauley, R. D.
2004. Anthropogenic sound: effects
behavior and physiology
of fishes. Marine Technology Society Journal
M.E. and L.A. Fuiman. 2004. Behavioral performance of wild-caught
red drum Sciaenops
(Linnaeus) larvae. Journal of Experimental
Marine Biology and Ecology 302(1):17-33.
M.E. and L.A. Fuiman. 2003. Causes of growth depensation
in red drum, Sciaenops
Biology of Fishes 66:49-60.
M.E. and M.C. Belk. 2001. Risk-assessment in western mosquitofish
do multiple cues have
additive effects? Behavioral Ecology
Sociobiology 51 (1):101-107.
M.E. 2000. The alarm response of Arius felis to chemical
Ecology 26 (7):1635-1647.
L.A., M.E. Smith, and V. Malley. 1999. Ontogeny of routine
speed and startle
red drum, with
a comparison of responses to acoustic
and visual stimuli. Journal of Fish
Biology 55 (supplement
Hobbies include fishing, camping, racquetball, and spending time
with my family.