Ciliary/decarboxylase activities as indicators of PTZ, photoperiod and Ca-ionophore effect on Crassostrea virginica (gmelin)

Abstract

1. 1. Lateral ciliary activity and DOPA decarboxylase were measured in the ctenidium of Crassostrea virginica (Gmelin). 2. 2. Activity of the lateral cilia is dependent upon branchial nerve (Paparo, 1985a,b) and on intracellular calcium homostasis (Baker, 1963; Rassmussen, 1970, 1971; Romero and Wittman, 1971; Blanstein et al., 1978). 3. 3. PTZ induced lamella morphogenesis in eytosomes with subsequent release of calcium into the cytosol. This cilio-inhibition was enhanced in the presence of additional calcium in the perfusate. 4. 4. Prolonged exposure to light also induces fully converted membranous eytosomes with subsequent production of a gradual lateral cilio-inhibition. Darkness produces the opposite effect, in that secondary membranous conversions of cytosomes are inhibited. 5. 5. In the presence of A-23187 (a calcium releasing agent), inhibition of lateral activity is produced, independent of cytosomal conversion. 6. 6. It is postulated that photic electrical and chemical stimulation of neuronal chromoproteins can lead to release of calcium from sequestered cytosomal stores which triggers a neuro-exocytosis of a neuroinhibitory transmitter, dopamine.