Abstract
A seasonal study of field-collected individuals of Porphyra leucosticta at Sidmouth, Devon, UK showed that the blade phase was present from April to September 2001. Specimens of P. leucosticta were epiphytic on Fucus serratus, Mastocarpus stellatus, Chondrus crispus and Osmundea pinnatifida, and epizoic on Mytilus edulis, often found growing in layers on the host. Field material was monoecious, with male and female gametangia in separate sori, but intermixed along the margins of thalli. Mean size (wet mass and dry mass, length and width) was lowest in April and greatest in July. All spores released in culture from field-collected material developed into conchocelis, except one individual, which released archeospores that developed into blades. The life history was completed in culture at both 15°C/long days (16:8 h light:dark cycle) and 15°C/short days (8:16 h light:dark cycle). A protothallus developed directly on the vegetative conchocelis filament by divisions of one of the vegetative cells and either detached and dropped to the bottom of the culture dish or remained as part of the conchocelis. The protothallus produced either archeosporangia or male and female gametangia or both. Chromosome numbers of n=3 in male gametangia, 2n=6 in zygotosporangia and 2n=6 in the conchocelis phase suggest that fertilisation had taken place.
References
Bird, C.J. and J.L. McLachlan. 1992. Seaweed flora of the maritimes I. Rhodophyta – the red algae. Biopress Ltd, Bristol. pp. 177.Search in Google Scholar
Brodie, J. and L.M. Irvine. 1997. A comparison of Porphyra dioica sp. nov. and P. purpurea (Roth) C. Ag. (Rhodophyta: Bangiophycidae) in Europe. Cryptogam. Algol.18: 283–296.Search in Google Scholar
Brodie, J.A. and L.M. Irvine. 2003. Seaweeds of the British Isles. Volume 1 Rhodophyta Part 3B Bangiophycidae. Intercept, Hampshire. pp. 167.Search in Google Scholar
Brodie, J., P.K. Hayes, G.L. Barker, L.M. Irvine and I. Bartsch. 1998. A reappraisal of Porphyra and Bangia (Bangiophycidae, Rhodophyta) in the northeast Atlantic based on the rbcL-rbcS intergenic spacer. J. Phycol.34: 1069–1074.Search in Google Scholar
Brodie, J., R. Nielsen and K. Gunnarson. 2001. The bangiophyte flora of the Faroe Islands. Fróðskaparrit (Annales Societatis Scientiarum Færoensis) 49: 25–36.Search in Google Scholar
Burzycki, G.M. 1984. A cultural and cytological study of the marine red alga Porphyra torta, with special emphasis on the location of meiosis. MSc thesis, University of Washington. pp. 120.Search in Google Scholar
Coll, J. and E.C. de Oliveira Filho. 1977. The nuclear state of ‘reproductive’ cells of Porphyra leucosticta Thuret in Le Jolis (Rhodophyta, Bangiales). Phycologia16: 227–229.10.2216/i0031-8884-16-3-227.1Search in Google Scholar
Conway, E. 1964. Autoecological studies of the genus Porphyra: I. The species found in Britain. British Phycological Bulletin2: 342–348.10.1080/00071616400650101Search in Google Scholar
Drew, K.M. 1949. Conchocelis-phase in the life-history of Porphyra umbilicalis (L.) Kütz. Nature164: 748–749.10.1038/164748a0Search in Google Scholar
Drew, K.M. 1954. Life history of Porphyra. Nature173: 1243.10.1038/1731243a0Search in Google Scholar
Fowler, J. and L. Cohen. 1990. Practical statistics for field biology. John Wiley and Sons, Chichester. pp. 227.Search in Google Scholar
Freshwater, D.W. and D.F. Kapraun. 1986. Field, culture and cytological studies of Porphyra carolinensis Coll et Cox (Bangiales, Rhodophyta) from North Carolina. Jap. J. Phycol. (Sôrui)34: 251–262.Search in Google Scholar
Gargiulo, G.M., De Masi, F. Genovese, G. and G. Tripodi. 1994. Karyology and effects of temperature and photoperiod on the life-cycle of Porphyra leucosticta Thuret in Le Jolis (Bangiales, Rhodophyta) from the Mediterranean Sea. Jap. J. Phycol. (Sôrui)42: 271–280.Search in Google Scholar
Gargiulo, G.M., F. Culoso and F. De Masi. 1999. Morphology and karyology of Porphyra atropurpurea from the Mediterranean Sea. Book of Abstracts, 2nd European Phycological Congress, Montecatini Terme, 20–26 September 1999. Montecatini 1999. p. 108.Search in Google Scholar
Guiry, M.D. and E.M. Cunningham. 1984. Photoperiodic and temperature responses in the reproduction of north-eastern Atlantic Gigartina acicularis (Rhodophyta: Gigartinales). Phycologia23: 357–367.10.2216/i0031-8884-23-3-357.1Search in Google Scholar
Holmes, M.J. 2004. Phenology and observations on the morphology, cytology and life history of species of Porphyra (Bangiales, Rhodophyta) from Britain. PhD Thesis, University of the West of England. pp. 187.Search in Google Scholar
Holmes, M.J. and J. Brodie. 2004. Morphology, seasonal phenology and observations on some aspects of the life history in culture of Porphyra dioica (Bangiales, Rhodophyta) from Devon, Britain. Phycologia43: 176–188.10.2216/i0031-8884-43-2-176.1Search in Google Scholar
Hommersand, M.H., S. Fredericq and J. Cabioch. 1992. Developmental morphology of Gigartina pistillata (Gigartinaceae, Rhodophyta). Phycologia31: 300–325.10.2216/i0031-8884-31-3-4-300.1Search in Google Scholar
Kapraun, D.F. and D.W. Freshwater. 1987. Karyological studies of five species of Porphyra (Bangiales, Rhodophyta) from the North Atlantic and Mediterranean. Phycologia26: 82–87.Search in Google Scholar
Kapraun, D.F., T.K. Hinson and A.J. Lemus. 1991. Karyology and cytophotometric estimation of inter- and intraspecific nuclear DNA variation in four species of Porphyra (Rhodophyta). Phycologia30: 458–466.10.2216/i0031-8884-30-5-458.1Search in Google Scholar
Kornmann, P. 1961. Die Entwicklung von Porphyra leucosticta im Kulturversuch. Helgoländer wiss. Meeresunters.8: 167–175.10.1007/BF01609953Search in Google Scholar
Kornmann, P. 1994. Life histories of monostromatic Porphyra species as a basis for taxonomy and classification. Eur. J. Phycol.29: 69–71.10.1080/09670269400650511Search in Google Scholar
Kornmann, P. and P.-H. Sahling. 1977. Meeresalgen von Helgoland. Benthische Grün-, Braun- und Rotalgen. Helgoländer wiss. Meeresunters.29: 1–289.Search in Google Scholar
Kornmann, P. and P.-H. Sahling. 1991. The Porphyra species of Helgoland (Bangiales, Rhodophyta). Helgoländer wiss. Meeresunters. 45: 1–38.Search in Google Scholar
Kristiansen, A. 1972. A seasonal study of the marine algal vegetation in Tuborg harbour, the Sound, Denmark. Bot. Tidsskr. 67: 201–244.Search in Google Scholar
Le Jolis, A. 1863. Liste des algues marines de Cherbourg. Mémoires de la Société Impériale des Sciences Naturelles de Cherbourg10: 5–168.Search in Google Scholar
Lindstrom, S.A. and K.M. Cole. 1992. Relationships between some North Atlantic and North Pacific species of Porphyra (Bangiales, Rhodophyta): evidence from isozymes, morphology, and chromosomes. Can. J. Bot.70: 1355–1363.10.1139/b92-170Search in Google Scholar
Lindstrom, S.C. and K.M. Cole. 1993. The systematics of Porphyra: character evolution in closely related species. Hydrobiologia260/261: 151–157.10.1007/BF00049014Search in Google Scholar
Lindstrom, S.C. and S. Fredericq. 2003. rbcL gene sequences reveal relationships among north-east Pacific species of Porphyra (Bangiales, Rhodophyta) and a new species, P. aestivalis. Phycol. Res.51: 211–224.10.1111/j.1440-1835.2003.tb00189.xSearch in Google Scholar
Markham, J.W. and E. Hagmeier. 1982. Observations on the effects of germanium dioxide on the growth of macroalgae and diatoms. Phycologia2: 125–130.10.2216/i0031-8884-21-2-125.1Search in Google Scholar
McGregor, B.J. 1992. Aspects of the biology of Porphyra (Bangiales, Rhodophyta) of the Isle of Man. PhD Thesis, University of Liverpool. pp. 204.Search in Google Scholar
Neefus, C.D., A.C. Mathieson, C. Yarish, A.S. Klein, A. West, B. Teasdale and E.J. Hehre. 2000. Five cryptic species of Porphyra from the Northwest Atlantic. J. Phycol.36 (supplement): 73.10.1046/j.1529-8817.1999.00001-217.xSearch in Google Scholar
Neefus, C.D., A.C. Mathieson, A.S. Klein, B. Teasdale, T.L. Bray and C. Yarish. 2002. Porphyra birdiae sp. nov. (Bangiales, Rhodophyta): a new species from the Northwest Atlantic. Algae17: 203–216.Search in Google Scholar
Nelson, W.A. and G.A. Knight. 1996. Life history in culture of the obligate epiphyte Porphyra subtumens (Bangiales, Rhodophyta) endemic to New Zealand. Phycol. Res.44: 19–25.Search in Google Scholar
Nelson, W.A., J. Brodie and M.D. Guiry. 1999. Terminology used to describe reproduction and life history stages in the genus Porphyra (Bangiales, Rhodophyta). J. Appl. Phycol.11: 407–410.Search in Google Scholar
Norton, T.A. 1991. Conflicting constraints of the form of intertidal algae. Br. Phycol. J.26: 203–218.10.1080/00071619100650191Search in Google Scholar
Notoya, M. 1997. Diversity of life history in the genus Porphyra. In: (M. Miyata and M. Notoya, eds) Present and future biology of Porphyra. Nat. Hist. Res. Special Issue3: 47–56.Search in Google Scholar
Olivi, G. 1794. Sopra una nuova spezie di Ulva delle Lagune Venete. Saggi Scientifici Letterari dell'Accademia di Padova 3: 144–154.Search in Google Scholar
Padilla, D.K. 1984. The importance of form: differences in competitive ability, resistance to consumers and environmental stress in an assemblage of coralline algae. J. Exp. Mar. Biol. Ecol.79: 105–127.Search in Google Scholar
Quinn, G.P. and M.J. Keough. 2002. Experimental design and data analysis for biologists. Cambridge University Press, Cambridge. pp. 537.Search in Google Scholar
Sidirelli-Wolff, M. 1992. The influence of temperature, irradiance and photoperiod on the reproductive life history of Porphyra leucosticta (Bangiales, Rhodophyta) in laboratory culture. Bot. Mar.35: 251–257.Search in Google Scholar
Sokal, R.R. and F.J. Rohlf. 1995. Biometry: the principles and practice of statistics in biological research. W.H. Freeman and Company, New York. pp. 887.Search in Google Scholar
West, A.L., A.C. Mathieson, A.S. Klein, C.D. Neefus and T.L. Bray. 2005. Molecular ecological studies of New England species of Porphyra (Rhodophyta, Bangiales). Nova Hedwigia80: 1–24.10.1127/0029-5035/2005/0080-0001Search in Google Scholar
Wittmann, W. 1965. Aceto-iron-haematoxylin-chloral hydrate for chromosome staining. Stain Technol.40: 161–164.10.3109/10520296509116398Search in Google Scholar
©2005 by Walter de Gruyter Berlin New York
