by Clupeid Fishes
Clupeid fishes (herrings and shads) are among the main prey of echolocating
cetaceans, such as the harbour porpoise (Phocoena phocoena) and
bottlenose dolphin (Tursiops truncatus)1. The echolocation clicks
of cetaceans are high frequency (80-120 kHz), high intensity (180-220
dB re 1mPa, peak-to-peak source level) sounds that reflect off objects
in the marine environment, such as fishes. Researchers studying
the distribution of blueback herring observed that they swam away
from echosounders used to quantify fish abundance, suggesting that
clupeids may be able to detect ultrasound.
Several years ago we determined the hearing thresholds of a clupeid,
the American shad (Alosa sapidissima), from 0.2 to 180 kHz, and
found they could indeed detect ultrasound (see figure on right)
(Nature, 1997, 389:341; J.
Acoust. Soc. Am., 104:562-568). We found that American shad
have best sensitivity from 0.2 to 0.8 kHz in the sonic range and
from 25 to 130 kHz in the ultrasonic range. American shad were also
able to detect simulated bottlenose dolphin (Tursiops truncatus)
echolocation clicks with a threshold that suggests they could detect
an echolocating dolphin at distances up to 187 m. The evolution
of a mechanism to detect predator ultrasound in fishes may parallel
the evolution of a mechanism by moths to detect their bat predators.
Auditory thresholds were determined for American shad using a classical
conditioning paradigm where fish learned to reduce heart rate whenever
they heard a sound. Once the fish learned the task, the parameters
of the sound was changed in frequency and intensity and the lowest
detectable sound was considered to be the threshold. Shad could
detect sound from 200 Hz to over 180,000 Hz (below, figure on left).
Hearing thresholds for shad may be compared to data for other fishes.
In particular, goldfish (Carassius auratus) is a 'hearing
specialist' and can only detect sounds to about 3,000 Hz. (While
the figure below to the right suggests that goldfish are far more
sensitive than shad at the lower frequencies, we have evidence to
suggest that shad thresholds below about 2,000 were masked in our
experimental situation). In contrast, the bottlenosed dolpin,Tursiops
truncatus, is able to detect sounds to above 150,000 Hz, and its
echolocation signal can be varied over most of the ultrasonic detection
range of shad (red rectangle in figure on right below).
our most recent studies, we (Mann, Higgs, Tavolga, Popper) have
used Auditory Brainstem Responses (ABR) to measure hearing capabilities
of several other clupeid species in order to ascertain whether ultrasonic
hearing is found in all Clupeiformes, or whether it is only found
in a limited number of species. Results show that only species related
to the genus Alosa, including American shad and gulf menhaden, detect
ultrasound, while other species, such as the Spanish sardine and
bay anchovy are only able to detect sounds to about 4 kHz (figure
An overview of ultrasound detection can be found in Popper (2000)
and in the following research papers.
D.A., Lu, Z., and Popper, A.N.
(1997) Ultrasound detection by a teleost fish. Nature 389:341.
D. A., Lu, Z., Hastings, M. C. and Popper, A. N. (1998).
Detection of ultrasonic tones and simulated dolphin echolocation
clicks by a teleost fish, the American shad (Alosa sapidissima). J. Acoust. Soc. Am., 104:562-568.
Mann, D. A., Higgs, D. M., Tavolga, W. N., Souza, M. J., and
Popper, A. N. (2001).
Ultrasound detection by clupeiform fishes. J. Acoust. Soc.
D. A., Higgs, D. M., Tavolga, W. N., and Popper, A. N. (2002).
Ultrasound detection by clupeiforme fishes. Bioacoustics,
Mann, D. A, Popper,
A. N. and Wilson, B. (2005). Pacific herring hearing does not
include ultrasound. Biology Letters, 22:158-161.
T. T. and Popper, A. N. (2003). Evasive responses of American
shad (Alosa sapidissima) to ultrasonic stimuli. Acoustics
Research Letters Online (ARLO), 4:25-30.
Song, J., Halvorsen, M.B., and Popper, A.N. (2004).
Neuronal encoding of ultrasonic sound by a fish. J.
Neurophysiol., 91:2590-2597. Doi:10.1152/jn.01200.2003.
Plachta, D.T.T., Mann, D.A., and Higgs, D. (2004). The response
of clupeid fishes to ultrasound: a review. ICES J. Mar. Sci.,