The physiology of the cortical reaction in the eggs of penaeid shrimp

Mature penaeid oocytes contain large membrane-bound cortical specializations (rods) in their cortex. The rods are composed of feathery elements consisting of a dense axis with numerous fibrillar projections perpendicular to the axis. Prior to spawning, the cortical rods move to the periphery of the oocyte where membrane fusion takes place between the oolemma and the rod's bounding membrane. At spawning the cortical rods are expelled from the oocyte to form a striking investment layer which rapidly dissipates. During the cortical rod dissipation a hatching membrane forms around the egg. [...]