Observations on the Developmental Morphology and Fine Structure of Pit Connections in Red Algae

Abstract

Pit connections, biconvex, equatorially constricted discs (0.3-0.7μ in diameter), develop between newly formed cortical and segment cells of Ceramium diaphanum. Biconvex, constricted forms represent early developmental stages of pit connections. Similar forms have been found in apices of Callithamnion roseum and Polysiphonia sp. As pit connections mature they increase mainly in width. Equatorial furrows become less pronounced. Flat, wide, lens-shaped forms consist of a granular material of high electron density. Current information on these structures suggests that their classification by Jungers is incorrect. Pit connections of red algae consist of a single body whose morphology varies with development.