Acoustic particle motion detection in the snapping shrimp (Alpheus richardsoni)

Many crustaceans produce sounds that might be used in communication.
However, little is known about sound detection in crustaceans, hindering
our understanding of crustacean acoustic communication. Sound detection
has been determined only for a few species, and for many species, it is
unclear how sound is perceived: as particle motion or sound pressure.
Snapping shrimp are amongst the loudest and most pervasive marine sound
sources. They produce snaps during interactions with conspecifics, and
they also interact with soniferous heterospecifics. If they can hear, then
sound could facilitate key behavioral interactions. We measured the
auditory sensitivity of the snapping shrimp, Alpheus richardsoni, using
auditory evoked potentials in response to a shaker table that generated
only particle motion and an underwater speaker that generated both
particle motion and sound pressure. Auditory detection was most sensitive
between 80 - 100 Hz, and auditory evoked potentials were detected up to
1500 Hz. Snapping shrimp responded to both the shaker table and the
underwater speaker, demonstrating that they detect acoustic particle
motion. Crushing the statocyst reduced or eliminated hearing sensitivity.
We conclude that snapping shrimp detect acoustic particle motion using the
statocyst, they might detect conspecifics and heterospecifics, and hearing
could facilitate key behavioral interactions.