Taxonomy, gamete morphology and mating types of Urospora (Ulotrichales, Chlorophyta) in North America

Abstract

L.A. Hanic. 2005. Taxonomy, gamete morphology and mating types of Urospora (Ulotrichales, Chlorophyta) in North America. Phycologia 44: 183–193.

Filament and gamete morphology, mating tests and hybridizations reveal the presence of eight taxa of Urospora from the Pacific and Atlantic coasts of North America. Three are dioecious and anisogamous: U. penicilliformis, U. neglecta and U. wormskioldii (synonym: U. vancouveriana). A fourth, U. bangioides, is monoecious and isogamous. Two are unisexual female variants, one with biflagellate parthenogametes (both coasts) and the other with quadriflagellate parthenogametes (Atlantic coast only). Two others are unidentified monoecious, anisogamous variants: one on the Atlantic coast and one on the Pacific coast. Urospora penicilliformis, U. neglecta and U. wormskioldii from the Pacific formed viable hybrids with their Atlantic counterparts and are considered to be conspecific with them. Urospora penicilliformis from the Pacific coast also formed viable hybrid zygotes with U. penicilliformis from Helgoland and Japan, again indicating conspecificity. On the Pacific coast, U. penicilliformis is the most common Urospora in the upper littoral, ranging from southern California to Homer, Alaska, with U. neglecta being restricted to British Columbia and Alaska. On the Atlantic coast, U. neglecta is the dominant Urospora, with U. penicilliformis subdominant in the upper littoral. Urospora wormskioldii is the dominant Urospora in the lower littoral on both coasts. Sexuality is reported for the first time in U. wormskioldii and for the first time in North America in U. bangioides. Monoecy and isogamy are confirmed in the genus. Urospora penicilliformis, U. neglecta and U. wormskioldii, although usually dioecious, are occasionally monoecious, indicating that the dioecious condition in these three species is not fixed. Emended descriptions of the species and genus are provided.

ACKNOWLEDGMENTS

I acknowledge with gratitude the following for providing live material of Urospora: Ruth Kornfeldt, Keith Stodley, Drs Peter Kornmann†, Mazukazu Tatewaki, David Cairns, Vickie Friesen and Sandra Lindstrom; for laboratory assistance: Cindy MacKenzie, Allan McLellan, Larry Green and Neil McNair; for helpful comments on earlier drafts: Larry Golden and Dr Thierry Chopin; for lengthy discussions and significant help with the submitted manuscript: Dr Sandra Lindstrom. Finally, I wish to express my appreciation to Dr Kathleen Cole, my PhD supervisor, who showed patience, good humour and above all many kindnesses to my family over nearly 40 years, and who welcomed me back to her laboratory 6 years ago. We will miss her good cheer and friendly laugh. I acknowledge financial support from the University of Prince Edward Island Senate Research Committee and the National Science and Engineering Research Council and the use of facilities in the Department of Botany, University of British Columbia.

Notes

† Deceased.