Mantis shrimp communicate with coloured patches on their bodies that are invisible to human eyes, an Australian researcher has found.
Mantis shrimp have the most complex visual systems that we know of. They can see UV, infrared and polarised light. Scientists have long thought that they use this vision for colour-based communication but there has been no way to test the idea.
Dr. Amanda Franklin and her colleagues at Tufts University in the USA hit upon the idea of using an ultrafast laser to ‘tattoo’ mantis shrimp.
“The ultrafast laser lightens a coloured patch located on the mantis shrimp’s ‘punching arm’, without causing harm to the mantis shrimp. It’s like tattoo removal,” Franklin says.
“Using this technique, we have shown that these UV-reflecting coloured patches are used to signal strength. We have evidence suggesting that mantis shrimp with darker patches are stronger than those with lighter patches.”
Mantis shrimp often fight one another, and they can strike their opponent with the acceleration of a .22 calibre bullet! The shrimp may use the coloured patches to assess their opponent’s strength before battle begins.
Image: A stomatopod in the lab at Tufts University. Credit: Amanda Franklin