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 (răb′dəm, -dŏm′)
A rodlike structure in the center of each ommatidium in the compound eye of an arthropod, composed of microvilli extending from the surrounding retinular cells.

[From Greek rhabdōma, bundle of rods, from Greek rhabdos, rod; see rhabdomancy.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Zoology) any of many similar rodlike structures found in the eyes of insects
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈræb dəm, -dɒm)

any of various small, rod-shaped anatomical structures.
[1875–80; < Late Greek rhábdōma bundle of rods; see rhabdo-, -oma]
rhab•do•mal (ræbˈdoʊ məl, ˈræb də məl) adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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They are ocelli consisting of a single lens below which lie elongated photoreceptors with rhabdoms located close to the base of the lens (Fig.
Specific anti-bodies generated against some of the opsins have also allowed studies of diurnal changes in their expression patterns in rhabdoms.
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.
1993; Schuh and Slater 1995), it can de added that the eyes dorsally have the ommatidia with a rhabdom pattern of R7 and R8 in tandem (Fischer et al.
Where this is not the case, this challenge appears to have been addressed by increased transparency of the cell bodies in the secondary eyes, increased size of the rhabdoms, and presence of an underlying reflective tapetum that approximately doubles the light path available to incident photons (Fig.
Areas of specific interest included the ommatidia and rhabdoms, basement membrane of the ommatidia, optic nerve fibers, and connective tissues near the lamina ganglionaris.
Type I (found in the two most ventral rows of the mid-band) is the simplest and is specialized for the analysis of polarized light, like the rhabdoms in ommatidia of the retinal hemispheres.
In most arthropod species that have superposition compound eyes, light reflected by the tapetum and not absorbed by the rhabdoms is visible as eyeshine (Kunze, 1979).
The rest of the eye is dominated by hypertrophied rhabdoms that fill most of the space between the cornea and the basement membrane [ILLUSTRATION FOR FIGURES 3A, C OMITTED].
Crustaceans inhabiting zones above 1000 m, on the other hand, frequently possess adaptations such as enlarged ommatidia, more voluminous rhabdoms, presence of retinal reflectors, etc., to improve the efficiency of photon capture.
Though a regular arrangement of rhabdomeric microvilli was not found, we postulate that this area represents a simple closed rhabdom. Furthermore, a small area of irregularly arranged microvilli which are provided by cells similar to those just described was found rather close to the origin of the optic nerve (Figs.