It’s easy to appreciate how incredible the biological engineering of a mantis shrimp is. Whether it’s the “smasher” or “spearer” variant, this unusual, persistently hostile critter constantly surprises researchers. Just last year, several studies revealed that it can communicate using patterns of light; now, a study published in the journal Scientific Reports has discovered how the mantis shrimp is able to produce such complex patterns of light.
Polarization is a property of certain electromagnetic waves, including visible light, whereby their electrical field travels in one or several different orientations as the wave moves forwards. Careful observations of the mantis shrimp species Gonodactylaceus falcatus revealed that they have patterns on their body that can reflect circularly polarized light; if a person could detect this type of light, it would be seen as “moving” in a circle or spiral pattern. Predators can’t see this type of communication, which means these sea-dwelling animals can “talk” in secret.
Controlled experiments demonstrated that these patterns are displayed primarily when the mantis shrimp needs to ward off another: Knowing how dangerous an encounter with another mantis shrimp could be, it picks up on these polarized patterns in order to maintain a safe distance. Unsurprisingly, the mantis shrimp is a solitary creature.
This new study expands on this knowledge. The research team from the University of Bristol’s School of Biological Sciences used specialized microscopes to look at the maxillipeds – appendages used for feeding – of several species of mantis shrimp, before corroborating their observations with some modeling.
They found that the shrimps' polarizing patches carefully manipulate light across their surface using a series of hollow "pores" that act as powerful reflectors. This mechanism, unlike anything seen before in the animal kingdom, allows these crustaceans to creatively manipulate microscopically thin sections of their body in order to produce a wide range of intense, vivid patterns of colorful, polarized light.
You wouldn’t want to anger one of these clown-colored fellows: they can smash through the glass walls of an aquarium. randi_ang/Shutterstock
Despite the fact that we cannot directly see this form of communication, we often apply the physical principles of polarized light to our daily lives: Examples include using polarized sunglasses to block out certain frequencies of light, or applying a polarizing lens to a microscope to view microbes or thin sections of rock samples in a different manner. Polarizers are also used in cameras and DVD players.
This new finding may lead to the development of more advanced polarizers that can remain small in size whilst still creating complex patterns of light. Dr. Nicholas Roberts, a member of the School of Biological Sciences and an author of the study, said in a statement: “When it comes to developing a new way to make polarizers, nature has come up with optical solutions we haven't yet thought of.”