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Mantis Shrimp Odontodactylus scyllarus
2007 of 3588

Mantis Shrimp Odontodactylus scyllarus

July 2, 2010
Mantis Shrimp Odontodactylus scyllarus Mantis shrimp Odontodactylus scyllarus. Crustaceans of this genus have recently been shown to be capable of circular polarization vision, a new visual modality in the animal kingdom. Also known as stomatopods, mantis shrimp are large and particularly violent marine crustaceans that aren't actually a kind of shrimp, but look something like one. The discovery was made by Justin Marshall of the University of Queensland in Australia, who describes circular polarized light (CPL) as a spiraling beam that spins either to the left or the right. Scientists had shown before that some animals, such as scarab beetles, reflect that kind of light, but they hadn't shown that any animal could actually see it--until now, that is. Using circular polarization vision required the stomatopods to evolve a kind of filter in their eyes, oriented at a precise 45 degree angle, to photoreceptors underneath that pick up on linearly polarized light. The filter turns the circularly polarized light into its linear form. Many animals make use of linearly polarized light, but to people, however, it is only glare, hence the need for polarized sun glasses. It isn't clear yet what exactly the mantis shrimp uses its newfound visual ability for in nature, but Marshall suspects is has something to do with reproduction. Stomatopods are known to use highly specialized color and linear polarization signals for complex social interactions, he noted. And by using circular-polarization imaging, his team has identified three species of stomatopods (within the genus Odontodactus) where CPL is reflected from the cuticles of males but not females. Those sex-specific reflective areas are on parts of the body that stomatopods frequently use for behavioral displays. [This research was supported by a National Science Foundation grant, awarded to Tom Cronin of UMBC and Roy Caldwell of Berkeley.] To learn more about this research, see "Mantis Shrimp Vision Reveals New Way That Animals Can See," on EurekAlert! (Date of Image: 1999)


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