Diminution and enlargement of the mosquito rhabdom in light and darkness

Abstract

The rhabdoms of the larval ocelli of the mosquito Aedes aegypti undergo morphological light and dark adaptation over periods of hours. The rhabdo in enlarges during dark adaptation and grows smaller during light adaptation. Diminution is exponential, enlargement linear, and rates of change are proportional to log light intensity. Rhabdoms maintained at a constant intensity level off at a constant volume inversely proportional to log intensity. We argue that changes in rhabdom volume after changes in light intensity reflect an influence of light on the turnover of photoreceptor membrane, and that the volumes at which rhabdoms level off represent equilibria between opposed processes of membrane loss and renewal. © 1975, Rockefeller University Press., All rights reserved.