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Brandon M. Casper, Phillip S. Lobel & Hong Y. Yan (2003): The hearing
sensitivity of the little skate, Raja erinacea: A comparison of two
methods. Environmental Biology of Fishes 68: 371-379, 2003.
Synopsis: We determined the hearing sensitivity of the little skate,
Raja erinacea, using two methods: Behavioral conditioning and the
auditory brainstem response (ABR). This marks the first time that the
hearing in any member of the Rajiformes has been examined and the
first time that the ABR method has been used with an elasmobranch. We
obtained audiograms of R. erinacea using each method and were found to
be statistically similar. The best hearing sensitivity for R. erinacea
was between 100 and 300 Hz. We compared the audiograms to audiograms
obtained from other species of elasmobranchs. This analysis showed
that R. erinacea, a bottom-dwelling elasmobranch, has less sensitive
hearing than the lemon shark, Negaprion brevirostris, and the bull
shark, Carcharhinus leucas, a free-swimming, raptorial
elasmobranch. However, R. erinacea showed sensitivity comparable to
that of the horn shark, Heterodontus francisi, another bottom-dwelling
elasmobranch; both species feed primarily on benthic prey. These
findings are in agreement with Corwin's hypothesis (1978) that hearing
sensitivity is correlated with feeding behavior. An examination of the
macula neglecta of R. erinacea found a total count of 10 000 hair
cells, which is within the range of other bottom-dwelling
elasmobranchs.
Key words: auditory brainstem response, behavioral conditioning, ear,
elasmobranchs, sharks, rays
URL of the article:
<a href="http://journals.kluweronline.com/article.asp?PIPS=5147966";
rel="nofollow">http://journals.kluweronline.com/article.asp?PIPS=5147966</a>
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Sonja Amoser, PhD student
Institute of Zoology, University of Vienna,
Althanstrasse 14, 1090 Vienna, Austria
phone: +43-1-4277-54467 or +43-664-5006106 (private phone)
email: [EMAIL PROTECTED]
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