Sexually reproducing populations of Peyssonnelia rosenvingii (Gigartinales, Rhodophyta) in the North Pacific

Abstract

Sexually reproducing populations of the marine red alga Peyssonnelia rosenvingii Schmitz (Peyssonneliaceae, Gigartinales), for which only spermatangia and monosporangia, borne on the same thalli, have previously been known, are reported from the cold-temperate region of Japan. Plants are reproductive in late autumn and early winter. Each carpogonial branch consists of four or five cells, and the suprabasal cell of three-to five-celled auxiliary cell branches functions as an auxiliary cell. The absence of spermatangia and the presence of large, non-reproductive plants during the fertile season suggest that the spermatangial sori are ephemeral. After presumed fertilization a connecting filament develops from the hypogynous cell and runs in the horizontal plane. It branches irregularly and fuses with several auxiliary cells, forming several gonimoblasts along its length. Each gonimoblast produces five to eight carposporangial chains in conspicuously elevated nemathecia up to 350 µm high. Tetrasporangia are also formed in similar nemathecia up to 300 µm high and have three-to eight-celled pedicels.

A new crustose red alga Peyssonnelia rumoiana (Rhodophyta, Gigartinales) from Japan

“…The degree of elevation of nemathecia varies among species of Peyssonnelia. For instance, P. rosenvingii Schmitz produces remarkably elevated nemathecia reaching 300-350 µm in height (Kato and Masuda 2000), whereas P. meridionalis Hollenberg et Abbott forms slightly elevated nemathecia reaching 72-86 µm in height . The nemathecia of Irvine and Maggs (1983); Maggs (1983) this study † Information taken from Maggs (1983) except for that with asterisk .…”

“…The number of cells constituting tetrasporangial pedicels also varies among species of Peyssonnelia. For example, P. rosenvingii has three-to eight-celled pedicels (Kato and Masuda 2000), whereas P. hongii Marcot-Coqueugniot (1980), P. armorica (Guimarães and Fujii 1999) and P. meridionalis have onecelled pedicels or lack pedicels. Peyssonnelia bornetii Boudouresque et Denizot, P. rubra (Marcot et al 1977;figs 7,9 and 11), P. harveyana J. Agardh (Perestenko 1980) and P. foliosa Montagne (Womersley 1994; fig.…”

“…The red algal genus Peyssonnelia (Peyssonneliaceae, Gigartinales) currently includes 70 species that have been chiefly described from tropical to warm-temperate regions in the world . In Japan the following eight species are known: Peyssonnelia caulifera Okamura (1899) including Nozawa's (1972a) report of P. squamaria (Gmelin) Decaisne, P. conchicola Piccone et Grunow (Nozawa 1972b), P. distenta (Harvey) Yamada 1930, P. dubyi P. Crouan et H. Crouan (Iwamoto 1960), P. japonica (Segawa) Yoneshigue (Segawa 1941; as Cruoriopsis japonica Segawa), P. meridionalis Hollenberg et Abbott , P. orientalis (Weber-van Bosse) Cormaci et Furnari (Nozawa 1972b; as Peyssonnelia rubra [Greville] J. Agardh f. orientalis Weber-van Bosse), and P. rosenvingii Schmitz (Kato and Masuda 2000). Iwamoto's (1960) report of P. dubyi from the north coast of Hokkaido requires re-examination.…”