NEURAL CONTROL OF MIGRATION OF PROXIMAL SCREENING PIGMENT BY RETINULAR CELLS OF THE SWIMMING CRABCALLINECTES SAPIDUS

Abstract

1. The position of proximal screening pigment (PSP) located in retinular cells of the compound eye of the crab Callinectes sapidus was assessed histologically after selective adaptation with plane polarized light. 2. The results showed the pigment position to be different within the cells of a single ommatidium. 3. The pigment position was similar in cells of that ommatidium which shared a common microvillar axis and different from those that did not. 4. The pattern of pigment distribution was similar in several adjacent ommatidia. 5. Serial sections showed that the pigment in cells sharing a common microvillar axis extended more distally than those that did not after a polarized adapting stimulus. 6. These results support the hypothesis that the migration of PSP is under neural control of the retinular cell where it is found and independent of activity in other cells in the same ommatidium or eye.