Summary: Molecular Ecology (2005) 14, 647651 doi: 10.1111/j.1365-294X.2005.02425.x
© 2005 Blackwell Publishing Ltd
Blackwell Publishing, Ltd.
Intriguing asexual life in marginal populations of
the brown seaweed Fucus vesiculosus
A. TATARENKOV,* L. BERGSTRÖM, R. B. JÖNSSON, E. A. SERRÃO,§ L. KAUTSKY¶ and K. JOHANNESSON*
*Department of Marine Ecology, Tjärnö Marine Biological Laboratory, Göteborg University, SE 452 96 Strömstad, Sweden,
Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå, Sweden, Department of Biology and
Environmental Sciences, Kalmar University, SE 391 82 Kalmar, Sweden, §CCMAR-Centre of Marine Sciences, University of Algarve,
Gambelas, 8005139 Faro, Portugal, ¶Department of Botany, Stockholm University, SE 106 91, Stockholm, Sweden
Reproduction of attached large brown algae is known to occur only by sexual zygotes.
Using microsatellites we show evolution of asexual reproduction in the bladder wrack
promoting population persistence in the brackish water Baltic Sea (< 6 psu). Here a dwarf
morph of Fucus vesiculosus is dominated by a single clone but clonal reproduction is also
present in the common form of the species. We describe a possible mechanism for vegeta-
tive reproduction of attached algae, and conclude that clonality plays an important role in
persistence and dispersal of these marginal populations, in which sexual reproduction is
impaired by low salinity.
Keywords: adventitious branches, Baltic Sea, brackish water, brown macroalgae, clonal repro-