(redirected from ommatidia)
Also found in: Dictionary, Medical, Encyclopedia.
Related to ommatidia: Rhabdomere
Graphic Thesaurus  🔍
Display ON
Animation ON
  • noun

Words related to ommatidium

any of the numerous small cone-shaped eyes that make up the compound eyes of some arthropods

References in periodicals archive ?
The male front narrower than the first falgellomere, and eyes very close to each other with ommatidia uniform in size (fig.
The input from the thousands of ommatidia is combined by the brain, to form a high-resolution image.
Here, the spaces between these artificial ommatidia can stretch to allow transformation in geometry from planar to hemispherical.
Lesions in the ommatidia of the eye were present in animals from both Rhode Island and Maine (Fig.
They consist of hundreds of thousands of tiny lens-capped optical units called ommatidia.
This section has some nice photographs and subjects, particularly a good description of the visual acuity that lobsters possess using ommatidia.
Eyes (in frontal view) conspicuous, oval-shaped; in lateral view eyes covering one third of head; 12 ommatidia across at widest portion of the eye (worker [N = 3] with only nine ommatidia at widest portion of the eye).
in preparation) and further suggest a tendency towards parallel evolution in some traits in these ants, including clypeal reduction between antenal lobes, reduction of the eyes to entirely absent or with few ommatidia, reduction in the number of antennal and palpal segments, and perhaps, simplification in sculpture.
Eye convex, protruding from side of head, centered on midpoint of side of head, without hairs between ommatidia.
An open rhabdom structure in the ommatidia of Heteroptera is considered a synapomorphy for Heteroptera, in contrast to the fused rhabdoms in Auchenorrhyncha and Coleorrhyncha (Fischer et al.
The ommatidia vary in size and resolution and are fused together, forming different points of focus.
318), it has been obvious for many years that such structures need not be exceptionally small and need not be extremely like ommatidia to behave like ommatidia.
For only one example, the necessity for some fiddler crabs to detect prey approaching over the horizon has caused the evolution of specific arrangements of the ommatidia in the eyes, which in turn favor males which erect vertical structures at the burrow (Christy and Salmon 1991).
However, it is more likely that arachnid eyes evolved from the expansion of individual ommatidia for the following reasons.