Seen from above, this oplophorid shrimp normally swims with its eyes extended on either side of the head. When the animal is alarmed, it swims rapidly backwards and in the process withdraws its eyes. This can be seen in the following video clip using the controls at the bottom of the picture.
When the shrimp is illuminated from the anterior, any unabsorbed light is reflected back out of the eye as eyeshine. This is often much brighter than the background and hence compromises the camouflage of the shrimp in its deep-sea environment. However, when the eyes are retracted during the escape response, an area of the eye without a reflective tapetum is directed towards the viewer. This can be seen in the following video clip.
Typically, when an oplophorid shrimp is threatened it releases a cloud of bioluminescent material and swims away backwards. Rather than the eyes reflecting this light, the shrimp instead presents the non-reflective part of the eye to the predator and escapes undetected.
Shelton P.M.J., Gaten E. & Johnson M.L (2000) The 'eye-blink' response of mesopelagic natantia, eyeshine patterns and the escape reaction. Crustacean Issues 12, 253-260.
Shelton P.J., Gaten E. & Herring P.J. (1992) Adaptations of tapeta in the eyes of mesopelagic decapod shrimps to match the oceanic irradiance distribution. Journal of the Marine Biological Association, 72, 77-88.
Last updated: March 2005
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