(Ski-doo-be-dop) We were at a party (Eww)
(Ski-doo-be-dop) His ear lobe fell in the deep (Eww)
(Ski-doo-be-dop) Someone reached in and grabbed it (Eww)
(Ski-doo-be-dop) Was a rock lobster (Eww)
— from “Rock Lobster” by The B-52’s
Most people will recognize the lyrics above from the B-52’s major hit “Rock Lobster,” released in 1978. But few probably realize that rock lobsters, also called spiny lobsters, make tunes of their own!
Rock lobsters are crustaceans in the family Palinuridae. Unlike true lobsters, in the family Nephropidae, which possess large chelae, or claws, rock lobsters can be identified by their big antenna and spine-covered bodies, for which they are named.
Six of the eight genera of rock lobsters employ stridulation, or rubbing two parts together, to produce sound. Sound emitted by stridulation is based on stick-slip friction, much like how the bow of a violin sticks and slips over the instrument’s strings to create sound. Rock lobsters move their soft-tissued plectrum, a ridged nub protruding from the base of the antenna, over a smooth file under each eye. Because the surface of the file is covered with microscopic shingles, the plectrum sticks and slips on the file. In this case, static friction dominates the mechanism, and the rasping or rattling sound produced correlates to the slipping phases . You can listen to some rock lobsters rocking out at the Patek Lab website, where they study acoustic communication of marine organisms.
But why do rock lobsters make sounds at all? Recall that sound is produced through vibrations of molecules in a medium, also creating oscillations of pressure. While humans typically perceive “sound” (auditory stimuli) as pressure variations within the ear canal, we can also feel certain frequencies of pressure waves in other parts of our bodies. Of course, aquatic invertebrates don’t have ears in the same sense as humans and other terrestrial animals. Instead, they perceive sound from the vibration of water molecules against sensory organs like statocysts or chordotonal organs, or sensory hairs on their bodies .
Several studies point to predator defense as a function of stridulation. For example, one study showed that both Palinurus argus and P. guttatus concurrently producesound with escape and/or retaliation (thrusting their antenna forwards) behaviors directed at one of their predators, the gray triggerfish .
Of course, just because scientists have a few behavior-related answers as to why rock lobsters perform stridulation doesn’t mean that these lobsters never rock-out just for fun! Why else would the B-52s have named a song after them? And more importantly, the rock lobster isn’t the only rock-star crustacean - several others also deserve a moment in the spotlight:
- Hermit crabs produce a chirping sound by stridulation. But instead of using stick-slip friction, the sounds of hermit crabs originate when ridges of their exoskeleton rub against each other.
- The American lobster, Homarus americanus, creates carapace vibrations by contracting internal muscles at the base of the second antennae, creating pulses in the water . Not many other crustaceans are known to create sound from inside their bodies!
- The mantis shrimp, in the family Stomapoda, creates a “rumble” of low-frequency sounds by contracting muscles beneath the back edge of the carapace, causing its carapace to vibrate .
- The snapping shrimp, which is a type of Decapod in the family Alpheidae, uses its asymmetric claws to produce a snapping sound by closing the larger claw, known as the snapper. The snapper has a plunger that slams into a socket at extreme velocity, pushing out a jet of water and resulting in a drop in pressure that creates cavitation bubbles, which generates loud snap sounds when the bubbles collapse .
 Patek, S. N., and J. E. Baio. "The Acoustic Mechanics of Stick Slip Friction in the California Spiny Lobster (Panulirus Interruptus)." Journal of Experimental Biology 210.20 (2007): 3538-546.
 "How Do Marine Invertebrates Detect Sounds?" Discovery of Sound in the Sea. University of Rhode Island.
 Bouwma, P. E. "Aspects of Antipredation in Panulirus Argus and Panulirus Guttatus: Behavior, Morphology, and Ontogeny." Electronic Theses, Treatises and Dissertations. (2006): 3466.
 Henninger, H. P. "Mechanisms Underlying the Production of Carapace Vibrations and Associated Waterborne Sounds in the American Lobster, Homarus Americanus." Journal of Experimental Biology 208.17 (2005): 3421-429.
 Patek, S.N., and R. L. Caldwell. “The stomatopod rumble: Low frequency sound production in Hemisquilla californiensis.” Marine and Freshwater Behavior and Physiology 39.2. (2006): 99-111.
 Versluis, M. et al. "How Snapping Shrimp Snap: Through Cavitating Bubbles."Science 289.5487 (2000): 2114-117.