"How do marine invertebrates produce sounds?" (continued)
Spiny lobsters, Palinurus elephas, are clawless lobsters that produce a rasping sound using their antennae. The method a spiny lobster uses to produce sound has been compared to that of a violin. In a violin, the bow "sticks and slips" over the strings due to friction, generating acoustic vibrations. Spiny lobsters also produce sound using "stick and slip" friction. When the lobster moves its antennae in certain ways, a piece of soft tissue called the plectrum rubs against a smooth, stiff file located near the eye resulting in the production of sound. Because the "stick and slip" method does not require hard parts, spring lobsters can still make sound when their exoskeleton is softened during molting. Most marine invertebrates that use stridulation to produce sound rely on hard surfaces. However, the spiny lobsters are unique in that they produce stridulatory sounds using a soft-tissue plectrum. This reduces their vulnerability during molting because they are still able to produce sound to ward off predators.
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Common spiny lobster, Palinurus elephas. Produces sound using the "stick and slip" method, a term used by researchers. Photo courtesy of Sheila Patek
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The New England mussel, Mytilus edilus, produces sound with its byssal threads, which are used to attach themselves to hard substrates. At temperatures above 10 degrees Centigrade, mussels can produce snapping sounds by stretching and breaking the byssal threads, these sounds are not intentionally produced. Sound production attributed to the New England mussel provided the first understanding of background noise levels produced by marine organisms in areas other than the southern and tropical coasts.
Male fiddler crabs use their enlarged claw, or cheliped, to produce sound by striking various parts of their body or the substrate which they are on. A variety of sounds produced this way have been described as drumming, honking, rasping, hissing, and rapping. Species specific sounds have been identified in recordings based on different frequencies and time intervals. For example, Uca pugilator produce rapping sounds between 600 and 2400 Hz and Uca rapax produce sounds between 300 and 600 Hz.
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| A fiddler crab can make rapping, honking and rasping sounds using its enlarged claw (cheliped). Photo courtesy of NOAA |
The tropical sea urchin, Diadema setosum, has been observed to produce crackling sounds through stridulation of its stiff spines during movement. Stridulatory sounds may also be produced by the Aristotle's lantern and the test. The Aristotle's lantern is found on the ventral side of the urchin and is used for breathing and eating. The test is the body cavity of the sea urchin. These two anatomical features rub against one another during feeding and breathing producing a crackling sound.
Additional Resources
- BBC News. 2000. Shrimp, bubble and pop. BBC News Online. 21 September, 2000.
- Clark, R. 2000. When snapping shrimp snap. StudyWorks! Online. November 2000.
- Duke University. 2001. The Fiddler Lobster. Duke News Service. May 11, 2001.
- Gilmore, R. G., Jr. 2003. Sound production and communication in the spotted seatrout. Pages 177-195. in S. Bortone, editor. Biology of the spotted seatrout. CRC Press Boca Raton, Florida.
- How Snapping Shrimp Snap (and flash) (University of Twente)
- Lohse, D., Schmitz, B. and Versluis, M. 2001. Snapping shrimp make flashing bubbles. Nature 413(6855): 477 - 478.
- Patek, S.N. 2001. Spiny lobsters stick and slip to make sound. Nature 411:153.
- Roach, J. 2001. Snapping shrimp stun prey with flashy bang. National Geographic News, October 3, 2001.
- Summers, A. 2001. The Lobster's Violin. Natural History Magazine - Biomechanics. June 2001.
- Versluis, M., Schmitz, B., Heydt, A. and Lohse, D. 2000. How snapping shrimp snap: through cavitating bubbles. Science 289 (5487): 2114-2117.
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