next message in archive
next message in thread
previous message in archive
previous message in thread
Index of Subjects
Index of Subjects Your pic is nice but not high enough magnification to see the detailed structure of the eyes, even more alien-looking than you may think. At least in some male mayflies, the eye is conspicuously bi-lobed, with the upper half optically quite different than the lower half and probably specialized for spotting females (this has been studied in other insects, mostly flies). The facets in the upper eye in some mayflies are square, not hexagonal as they are in the lenses of the lower eye. Square facets in other arthropods (crustaceans) have reflecting layers inside, lining their square optical tubes, and behave like 2-Dimensional retroreflectors to focus light usefully inside the eye into a single image. The mayfly's upper eye therefore possibly may work similarly. The biological structures are somewhat analogous to the retroreflectors left on the moon by astronauts. The moon ones have been used to reflect back laser pulses aimed from earth, allowing for instance the earth-moon distance to be monitored sensitively. Steve Quoting nancy dowd <nancypdowd@gmail.com>: > I guess I never really looked closely enough at a mayfly to notice the > prominent (almost alien looking) eyes: > http://www.flickr.com/photos/92981528@N08/9367703219/ > > This one has its tail filaments snagged in a spider web. I freed it > and it flew off. Any ID corrections are welcome. > > Nancy > >
next message in archive
next message in thread
previous message in archive
previous message in thread
Index of Subjects