Developmental morphology of Chondrus crispus (Gigartinaceae, Rhodophyta)

Abstract The vegetative and reproductive development of the type species of Chondrus, C. crispus Stackhouse (Gigartinaceae, Rhodophyta), is described based on material from Britain and Ireland. Chondrus is distinguished from other members of the Gigartinaceae primarily by the absence of enveloping secondary filaments in the cystocarp. The procarp of C. crispus is typical for members of the Gigartinaceae and functional auxiliary cells form numerous enucleate protrusions, each of which potentially cuts off a gonimoblast initial. Gonimoblast filaments are narrow, uninucleate and resemble the connecting filaments found in non-procarpic families of red algae. Only the apical gonimoblast cellsare densely filled with cytoplasm, the rest being highly vacuolate. Medullary cells are transformed into nutritive and potential generative cells as the gonimoblasts ramify through the medulla. The nuclei in each medullary cell undergo mitosis simultaneously, followed by protein synthesis and breakup of the central vacuole...