On a small island, Carrie Bow Cay, six miles from the coast of Belize lives a colony of very interesting shrimp. Snapping, or pistol shrimp as they are sometimes affectionately named, have complicated social structures one might only compare with that of bees. This social structure, called eusociality, is characterized by the different roles that individuals play within the colony.
The males with the largest pincers serve as defense for the colony. The pincers of the snapping shrimp are intense. They can snap at a rate of 60 miles per hour and the forceful bubbles that this motion creates is enough to stun or even kill prey. If you were in the ocean, one shrimp would sound like thunder from a loud storm and a group together would be like a jet zooming by.
Males guard the queens in this fashion like soldiers in an army. There is generally one egg laying queen and the rest of the 300 individual strong colony tends to the young. They live within the canals of sea sponges and therefore use it as not only shelter but a food resource simultaneously. They are the only aquatic species with this complex social structure and it is strange that it would be an evolved strategy. It doesn’t go along with the whole selfish nature of well, nature. In the animal kingdom the goal in life is generally to produce offspring to spread your genes and make sure that offspring has what it needs to do the same. It must be somehow more beneficial to be altruistic, or selfless, and sacrifice your individual reproductive fitness for the health of the colony.
This is a new development and researchers are still trying to understand how it works. Although there are some problems. Active coral populations are decreasing due to coral bleaching. Since these organisms rely on the sponges as their host, they are declining as well. It’s a race to understand these bee-like aquatic organisms before there aren’t enough left.
Additional Reading:
- Eusociality in Coral Reef Shrimp (Nature )
- Snapping Shrimp and Hidden Sponges (Time Magazine)
- A comparative approach to trade-offs in social sponge-dwelling Synalpheus shrimps (PLOS, March 2018)
Image Credits:
- Thumbnail: CSIRO [CC BY 3.0 (https://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons
- Snapping Shrimp: By Michael Marmach [CC BY 4.0 (https://creativecommons.org/licenses/by/4.0)], via Wikimedia Commons
