ommatidium


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Related to ommatidium: Rhabdomere

om·ma·tid·i·um

 (ŏm′ə-tĭd′ē-əm)
n. pl. om·ma·tid·i·a (-ē-ə)
One of the optical units, consisting of photoreceptors and usually one or more lenses, that make up a compound eye of an insect or a crustacean.

[New Latin, diminutive of Greek omma, ommat-, eye; see okw- in Indo-European roots.]

om′ma·tid′i·al (-ē-əl) adj.

ommatidium

(ˌɒməˈtɪdɪəm)
n, pl -tidia (-ˈtɪdɪə)
(Zoology) any of the numerous cone-shaped units that make up the compound eyes of some arthropods
[C19: via New Latin from Greek ommatidion, from omma eye]
ˌommaˈtidial adj

om•ma•tid•i•um

(ˌɒm əˈtɪd i əm)

n., pl. -tid•i•a (-ˈtɪd i ə)
one of the units that make up the compound eye of insects and other arthropods.
[1880–85; < New Latin < Greek ommat-]
om`ma•tid′i•al, adj.

om·ma·tid·i·um

(ŏm′ə-tĭd′ē-əm)
Plural ommatidia
One of the tiny light-sensitive parts of the compound eye of insects and other arthropods. An ommatidium resembles a single simplified eye. See more at compound eye.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.ommatidium - any of the numerous small cone-shaped eyes that make up the compound eyes of some arthropods
ocellus, simple eye, stemma - an eye having a single lens
compound eye - in insects and some crustaceans: composed of many light-sensitive elements each forming a portion of an image
References in periodicals archive ?
At the very center of each ommatidium are the dendrites of one or more neurons called eccentric cells that are electrically coupled to the retinular cells (Fahrenbach, 1969, 1975).
Printed images were magnified, and optical microscope images were used to obtain measurements of dorso-ventral distance (eye width) and anterior-posterior distance (eye length) of the compound eyes, and the SEM images were used to obtain measurements of individual square ommatidium area per eye using a slide caliper (GB/T1214.
Each ommatidium has a cornea to focus the light, a long cone full of photoreceptors, and a single axon (neuron) link to the optic nerve at the end, to connect it to the brain.
Each small eye, known as an ommatidium, consists of a corneal lens, a crystalline cone, and a light sensitive organ at the base.
Each ommatidium has its own cornea, lens, and photoreceptor cells for distinguishing brightness and color.
Most of the fossils are fully articulated (excluding macrophytes) and many preserve soft tissues, and organic patterns and structures rarely found in the fossil record: patterns of colouring, nerviation, gut tracts, and ommatidium of insects, stomach contents and muscles of fishes, skin and integumentary tissues of such as frogs, salamanders, lizards, crocodiles and dinosaurs.
Ant compound eye: size-related ommatidium differences within a single wood ant nest.
Since insects have compound eyes, this will amount to favoring a particular ommatidium (individual optical tube radiating out from the center of the compound eye).
No apparent borders between each ommatidium or between the compound eye and the head were observed.
Using this reconstruction of the molt as a base, we added to it every ommatidium in the Stage X post-molt animal (prosomal width, 37 mm) that was not present or distinguishable in the molt (Fig.
The width of the retinal layer, measured as retina length per ommatidium in the eye of both males and females, also increased in relation to greater individual body size (Fig.