Morphology of adaptation and morphogenesis in stomatopod eyes

Abstract

Ommatidia of eyes of stomatopods change with adaptation to light or dark. With dark adaptation the crystalline cones shorten and the retina becomes longer. This is due to contractions of myofibrils in veils surrounding the cones, while microtubules within the accessory pigment cells maintain the cytoarchitecture of the ommatidia. Here we describe the changes in Lysiosquillina maculata, a stomatopod living in an extremely bright habitat, which is compared to stomatopods from other ambient light conditions. The postlarval eye of stomatopods grows over the larval eye, gradually substituting it. Growth starts from a morphogenetic furrow at the inner border with the stalk. Similarly, in the adult eye as well at the inner margin between the stalk and the cornea, a morphogenetic furrow is inserted, which at its interior contains a proliferation tissue with clusters of developing ommatidia. At its distal side the proliferation tissue appears to generate the dioptric apparatus, i.e. veils, corneagenous cells and cones, and at its more proximal part the basement membrane, accessory pigment cells and retinular cells. The ommatidial components grow at different speeds.