The structure and reproduction of Patenocarpus paraphysiferus gen. et sp. nov. (Dermonemataceae, Nemaliales, Rhodophyta)

Abstract

Patenocarpus paraphysiferus gen. et sp. nov. (Dermonemataceae, Nemaliales) is described from the western Pacific. The carpogonial branch is formed as a lateral branch of an assimilatory filament and is composed of four to five cells. After fertilization, the zygote divides transversely and the upper daughter cell alone takes part in the formation of gonimoblast filaments. Sterile involucral filaments are developed prominently after fertilization. While the gonimoblast filaments are developing, the terminal cell of each neighbouring assimilatory filament produces a paraphysis. The gonimoblast filaments produce horizontal branches which penetrate both the assimilatory filaments and the paraphyses, resulting in a diffuse carposporophyte. Patenocarpus is similar to Liagora (Helminthocladiaceae) and to Yamadaella and Dotyophycus (Dermonemataceae) in both external and internal thallus morphology, but differs from them in its diffuse carposporophyte and the formation of paraphyses in the region of the carposporophyte.