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n. pl. re·tin·u·lae (-lē)
A cluster of pigment-containing photosensitive cells in each ommatidium of the compound eye of an arthropod.

[New Latin rētinula, diminutive of Medieval Latin rētina, retina; see retina.]

re·tin′u·lar adj.
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.


of or relating to the retinula
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
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In an adult animal, each LE contains more than a thousand ommatidia consisting of a conical lens below which are located 5-12 photoreceptors, also called retinular cells, arranged like the sections of an orange.
Retina.--The nearly hemispherical retina is composed of a layer of epithelial retinular cells containing basally (or peripherally) located nuclei with a distinctive arrangement of heterochromatin (Fig.
Spectral sensitivities of retinular cells measured in intact, living flies by an optical method.
argus eyes contain two spectral classes, with visual pigment in the cells of the main rhabdom (R1-7) absorbing maximally at 510 nm and pigment in the eighth retinular cells (R8) at 370 nm (Cummins et al., 1984).
Short wavelength pigments are sometimes not seen in microspectrophotometry because they only occur in the eighth retinular cell.
plebs, which has about 260 ommatidia with the five retinular cells per rhabdom typical of other amphipods (Hallberg et al., 1980).
The pigment cells are shaped to form three cups, and within each cup are two to six photoreceptors, termed retinular cells (Kauri, 1962; Walley, 1969; Walker et al., 1987; Clare and Walker, 1989).
Polarized light responses from retinular cells and sustaining fibers of the mantis shrimp.
amphitrite cyprid, the nauplius eye is composed of three pigment "cups" (two lateral and one ventral), with each cup containing four retinular cells.
To determine the rhabdom volume density, rhabdom areas were measured on micrographs of transverse and longitudinal sections of the retinular cell layer and recorded as a proportion of the total area.
Photoreceptor (retinular) cells were also labelled, but much less intensely than eccentric cells (9).
(Bursey, 1975; Gaten, 1994) - a distal retinula cell (R8) with four cytoplasmic lobes occupies the tier between the crystalline cone and the seven regular retinular cells, but in Paralomis an ommatidial retinula is composed of only seven regular cells (1-7) and lacks the distal eighth cell.