Isogamy and a Fucalean Type of Life History in the Antarctic Brown Alga Ascoseira mirabilis (Ascoseirales, Phaeophyta)

AbstractCoal Nunatak is an ice-free inland nunatak located on southern Alexander Island, adjacent to the west coast of the Antarctic Peninsula. Situated close to the Antarctic continent, it is characterized by harsh environmental conditions. Macroscopic colonization is restricted to micro-niches offering suitable conditions for a small number of lichens and mosses. The extreme environmental conditions place particular pressures on colonizers. Lepraria borealis is the dominant crustose lichen species present on Coal Nunatak, and shows distinctive features in its life history strategy, in particular expressing unusually low selectivity of the mycobiont towards potential photobionts. To assess selectivity, we measured algal DNA sequence polymorphism in a region of 480–660 bp of the nuclear internal transcribed spacer region of ribosomal DNA. We identified three different photobiont species, belonging to two different genera. We interpret this strategy as being advantageous in facilitating the colonization and community dominance of L. borealis under the isolation and extreme environmental conditions of Coal Nunatak.

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The antileishmanial activity of the antarctic brown alga Ascoseira mirabilis Skottsberg

Natural Product Research ◽

10.1080/14786419.2020.1782403 ◽

2020 ◽

pp. 1-5

Author(s):

Leandro da Costa Clementino ◽

Fernando Bombarda Oda ◽

Thaiz Rodrigues Teixeira ◽

Renata Spagolla Napoleão Tavares ◽

Pio Colepicolo ◽

...

Keyword(s):

Brown Alga ◽

Antileishmanial Activity ◽

The Antarctic

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The influence of temperature on the life history of the Antarctic nematode Panagrolaimus davidi

Nematology ◽

10.1163/1568541044038641 ◽

2004 ◽

Vol 6 (6) ◽

pp. 883-890 ◽

Cited By ~ 8

Author(s):

Russell Millar ◽

David Wharton ◽

Ian Brown

Keyword(s):

Life History ◽

Life History Strategy ◽

Major Influence ◽

Free Living ◽

Egg Incubation ◽

Polar Species ◽

Threshold Temperatures ◽

Influence Of Temperature On ◽

History Of ◽

The Antarctic

AbstractPanagrolaimus davidi is a free-living microbivore, associated with moss and algal patches in coastal regions around Ross Island, Antarctica. In laboratory experiments, temperature had a major influence on P. davidi life history parameters. The optimal temperature occurred between 25 and 30°C and the temperature at which population growth ceased was estimated at 6.8°C. Threshold temperatures for developmental processes were in the range 4.1°C (for egg incubation) to 7.6°C (for generation time). The life history strategy of P. davidi shows r-selected features and is more similar to temperate free-living nematodes than to other polar species, which show K-selected features. In the Antarctic, P. davidi is forced to remain dormant for long periods and growth occurs intermittently when conditions allow, suggesting A selection. The life history of P. davidi thus exhibits both A and r-selected features.

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Longitudinal Profiles of Growth, Photosynthesis and Light Independent Carbon Fixation in the Antarctic Brown Alga Ascoseira mirabilis

Botanica Marina ◽

10.1515/botm.1995.38.1-6.157 ◽

1995 ◽

Vol 38 (1-6) ◽

Cited By ~ 28

Author(s):

I. Gómez ◽

D. N. Thomas ◽

C. Wiencke

Keyword(s):

Brown Alga ◽

Carbon Fixation ◽

Longitudinal Profiles ◽

The Antarctic

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Taxonomic implications of gamete fusions in the parasitic brown alga Herpodiscus durvillaeae

Canadian Journal of Botany ◽

10.1139/b90-178 ◽

1990 ◽

Vol 68 (6) ◽

pp. 1398-1401 ◽

Cited By ~ 5

Author(s):

Akira F. Peters

Keyword(s):

Life History ◽

Life Cycle ◽

New Zealand ◽

Key Words ◽

Brown Alga ◽

Durvillaea Antarctica ◽

Taxonomic Implications

Field material of Herpodiscus durvillaeae, a New Zealand endemic parasitic brown alga growing in the thalli of Durvillaea antarctica, was studied in the laboratory. Pale zoids released from diminutive gametophytes, which were attached to the walls of unilocular sporangia and vegetative filaments of Herpodiscus, acted as isogametes. A heteromorphic life cycle with alternation of an endophytic parasitic sporophyte and a diminutive gametophyte is thus proposed for H. durvillaeae, and taxonomic implications of this life history are discussed. Key words: Herpodiscus durvillaeae, sexuality, life history, Phaeophyceae, Durvillaea antarctica, parasite.

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