Cavitation induced by snapping shrimp

Snapping shrimp (Alpheus heterochaelis), also called pistol shrimp, is usually 3–5 cm in length but it has a remarkably  disproportionate large claw, which sometimes is even larger than half of the shrimp's main body. The claw has a pistol-like feature, containing two parts: a protruding plunger (marked as 'pl' in the following figure) and a matching socket (marked as 's' in the following figure). The claw can be rapidly closed, resulting in a high-speed liquid jet containing cavitation bubbles and very loud noise generated during the collapse of the above bubbles. The emitted powerful cavitation bubbles is capable of stunning or kill preys.

Snapping shrimp. YouTube

The structure of claw of snapping shrimp. Reproduced from Versluis,et al (2000).

The process of snapping captured by high-speed camera. Reproduced from Versluis,et al (2000).

The source levels of emitted noise is as high as 190 to 210 dB (peak to peak; referenced to 1 mPa at a distance of 1 m). This severe noise also limit the usage of active or passive sonar underwater. Therefore, snapping shrimp is one of the loudest animals in the sea.

The cavitation bubbles generated by snapping shrimp is so powerful that they can also emit intense flash of light during bubble collapse, termed as shrimpoluminescence. The temperatures inside bubbles during collapse is estimated to be at least 5,000 K.

References

Michel Versluis,et al (2000). How Snapping Shrimp Snap: Through Cavitating bubbles, Science, 289, 2114. DOI: 10.1126/science.289.5487.2114

Detlef Lohse, Barbara Schmitz, Michel Versluis (2001). Snapping shrimp make flashing bubbles, Nature, 413, 477-8.