Rhopalium

Moon jelly (Aurelia aurita) with rhopalia visible in indentations of rim

Rhopalia (singular: rhopalium) are small sensory structures of Scyphozoa (typical jellyfish) and Cubozoa (box jellies). In Aurelia they lie in marginal indententions around the bell and are flanked by rhopalial lappets. Specialized structures to sense light (ocelli) and perceive gravity (statoliths) are usually present. They also control the pace of swimming-muscle contraction.

Cubozoan ocelli are the most complex of Cnidarians, and resemble the image-forming eyes of squids, octopuses and vertebrates.

swing of the rhopalia of Tripedalia cystophora

References

Meglitsch, Paul A. (1991). Invertebrate Zoology, Oxford University Press, 86. ISBN 0-19-504900-4.
Ruppert, Edward E.; and Fox, Richard S. (1988). Seashore Animals of the Southeast, University of South Carolina Press, 29. ISBN 0-87249-535-3.

External links

Vision in animals

Vision	Birds Cats Chameleons Dinosaurs Dogs Fishes Horses Toads

Eyes	Arthropod eye Compound eye Eagle eye Eye shine Simple eye in invertebrates Mammalian eye Human eye Mollusc eye Cephalopod eye Gastropod eye Holochroal eye Parietal eye Schizochroal eye

Evolution	Evolution of the eye Evolution of color vision Evolution of color vision in primates

Coloration	Albinism in biology Animal coloration Aposematism Camouflage Chromatophore Counter-illumination Countershading Crypsis Deimatic behaviour Disruptive coloration Eyespot (mimicry) Mimicry Structural coloration Underwater camouflage

Related topics	Animal senses Blindness in animals Eyespot apparatus Feature detection Infrared sensing in snakes Monocular deprivation Ommatidium Palpebral (bone) Pseudopupil Rhopalium Underwater vision Visual perception

This article is issued from Wikipedia - version of the Sunday, June 14, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.

Rhopalium

See also

References

External links