retinula


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retinula

(rĭ-tĭn′yə-lə)
n. pl. retinu·lae (-lē)
A cluster of pigment-containing photosensitive cells in each ommatidium of the compound eye of an arthropod.

re·tin′u·lar adj.
References in periodicals archive ?
If a retinula cell possesses a visual pigment, the absorption of the long wavelength quanta has the same effect on a receptor as the absorption of a short wavelength quanta (the principle of univariance; Naka and Rushton, 1966).
saltator, like some other amphipods, possesses an undifferentiated cornea, a fused-type rhabdom attached to the crystalline cone, and five retinula cells in each ommatidium (Ball, 1977; Meyer-Rochow, 1978; Hallberg et al.
The rhabdoms in Paralomis are extraordinarily well developed and occupy up to 85% of the available cytoplasmic space in the distal and central regions of the retinula [ILLUSTRATION FOR FIGURE 4 OMITTED].
The density of these granules seems not to differ from that of granules in the shallow-water half-crabs, but screening pigment granules in the retinula cells are far less numerous in Paralomis.
In the proximal layer, the retinula cells become slender as shown in Figure 5.
The reflecting tapetum on the proximal side of the retinula is massively developed, and it is evident that the eye is designed to maximize photon capture.