cucurbitae females had smaller individual square ommatidium
area than males (376.
In essence, each ommatidium
is an individual, low-resolution eye.
The confining effects of microbial mats and algae might also promote phosphatization of soft parts, such as gut tracts of fish and aquatic insects and of insect ommatidium
contains four large retinula cells (R1-4) and one small (R5).
exotica grew, the visual angles, representing optical catchment per ommatidium
, also remained basically the same (i.
We observed a gradient of ommatidial diameters within the array, with the largest ommatidium
at the posterior apex, and the smallest at the base.
Our strategy for examining the retinal code underlying behavior is to first videotape the lateral eye's view of its underwater world with an animal-mounted camera ("CrabCam") while simultaneously recording from a single optic nerve fiber of an ommatidium
viewing the central region of the videotaped scene (Passaglia et al.
In compound eyes, the unitary structure composed of optics, photoreceptors, and associated pigment cells is called an ommatidium
The field of view of a single ommatidium
defines the narrow excitatory center, whereas the neural network connecting neighboring ommatidia ([sim]200) generates the wide inhibitory surround.
We tease away a single active optic nerve fiber corresponding to a single ommatidium
and pull it into a micro-suction electrode.
The strobic illumination by the beams strongly modulates the firing rate of an ommatidium
, with peak firing rates reaching three times the mean .
To evaluate the possible clock influence on the strength of lateral inhibitory interactions, we compared the steady state optic nerve discharge of a single dark-adapted ommatidium
over a wide range of light intensities during the day and at night.
The final step was to optically isolate the ommatidium
of the single active nerve fiber by aligning a fiber optic light pipe (70 [[micro]meter] diameter) along the axis of the ommatidium
and in contact with the cornea (4).
Because photon catch is proportional to the cross-sectional area of ommatidial corneal facets, a single Limulus ommatidium
A glass microelectrode filled with 3 M KCl (25 M[Omega]) was connected to a DC bridge amplifier (Electronics Shop, Rockefeller University) and advanced into an ommatidium
using a Burleigh Inchworm (Burleigh Instruments, Fishers, NY) attached to a manipulator.