Little research has been done on how marine invertebrates use sound for communication. Snapping shrimp, spiny lobster, and fiddler crabs have been shown to produce sounds for defensive purposes and certain fiddler crabs also appear to produce sounds for courtship.

The snapping shrimp, Alpheus heterochaelis, produces sound in a most interesting and unique way. Upon closure of its enlarged claw, or cheliped, a bubble is formed that cavitates producing a loud popping sound (see How do marine invertebrates produce sound?). The force of the cavitating bubble is so powerful that it can stun or kill prey items. In the same way, the bubble is used to ward off predators.

Snapping Shrimp. Courtesy of Department of Applied Physics, University of Twente

The spiny lobster, Palinurus elephas, produces stridulatory sounds via its plectrum and file when the antennae are moved (see How do marine invertebrates produce sound?). Research conducted in aquariums showed defensive posturing and clicking sounds produced by the spiny lobster in response to predatory behavior by the gray triggerfish, (Balistes capriscus).

Fiddler crabs produce sound by striking their enlarged cheliped against other body parts or the seafloor (see How do marine invertebrates produce sound?). These sounds may be used to communicate information to other fiddler crabs about the presence of a nearby predator. Because these sounds are transmitted through the seafloor, they are sensed by mechanoreceptors. This allows fiddler crabs to communicate warning signals to other crabs that are nearby or located in burrows. Male fiddler crabs may also produce sound in this way to court females for reproduction.

A fiddler crab can use its cheliped to produce sound to warn others that a predator is coming. Photo courtesy of Jerry Prezioso

It is possible that sound production may play a role in the social dynamics of other marine invertebrates but additional research is needed to better understand how marine invertebrates may communicate using sound.

Additional Resources
• Patek, S.N. 2001. Spiny lobsters stick and slip to make sound. Nature 411:153.
• Peter Bouwma (Florida State University) - Function of spiny lobster sound production
• Sebeok, T., ed, 1977, How Animals Communicate, Indian University Press, Bloomington, 305-307.

For more information on how other marine animals communicate using sound, use the following links:
Marine Mammals	Fish	Invertebrates