Snapping Shrimp

Whenever I think about the ocean I picture a relaxing and quiet realm. There’s probably coral and the fish that live there. I don’t normally picture there being a species of shrimp that disturbs the silence.

The snapping shrimp (Alpheidae) has a large snapper claw that it can close rapidly and produce a loud snapping sound. The snapper claw has a plunger and socket, when the claw is closed rapidly the plunger is pushed into the socket causing water to be displaced. A fast water jet is created from the collapse of a cavitation bubble (Versluis et. al, 2000). Because cavitation bubbles collapse quickly shock waves are emitted (Lauterborn & Ohl, 1998). The shock waves created by the snapping shrimp can be used as a means of communication, defence, or predation (Versluis et. al, 2000).

Even though sensory hairs on the snapping claws are used for communication (Versluis et. al, 2000), it is thought that the evolution of this claw did not occur for intraspecific fighting but for predation. The nutritional advantage of individuals likely contributed to the original evolution of this claw (Collier & Stingl, 2013). The more efficient and powerful an individual’s claw is the more likely the individual is of obtaining food and therefore passing on genes to future generations. The sensors on the claws are helpful in determining the size of claws an opposing shrimp has and help the shrimp determine whether or not it should fight their opponent. However, some large-clawed individuals may try to use deceit to prevent fighting to the death because there is little advantage (Collier & Stingl, 2013). In most cases deceit isn’t a common behaviour because it has a high risk. Many times the cost of the deceitful action may be higher than the benefit and therefore harm an individual.

Watch the snapping shrimp in action:

References:

Collier, J & Stingl, M 2013, ‘Evolutionary Moral Realism’, Biological Theory, vol. 7, no. 3, pp. 218-226, doi:10.1007/s13752-012-0067-x.

Lauterborn, W & Ohl, CD 1998, ‘Cavitation bubble dynamics’, Ultrasonics Sonochemistry, vol. 4, no. 2, pp. 65-75, doi:10.1016/S1350-4177(97)00009-6.

Versluis, M, Schmitz, B, Heydt, A & Lohse, D 2000, ‘How snapping shrimp snap: through cavitating bubbles’, Science, vol. 289, no. 5487, pp. 2114-2117, doi:10.1126/science.289.5487.2114.