Variability for mixis initiation in
Brachionus plicatilis
E. Aparici, M.J. Carmona, M. Serra-2001
Hydrobiologia, 446/447: 45-50
Abstract:
Deductions from both evolutionary models and inductive argumentation from
empirical data support the notion of intraspecific variability for the
initiation of sexual reproduction (mixis) within rotifer populations. In
this study, we focus on the time and density at which mixis is initiated in
a growing population. Cyclical parthenogenetic clones of Brachionus
plicatilis established by hatching of resting eggs, isolated from a natural
habitat, have been tested at the start of their sexual phase. Clones
exhibited great variation for this trait, their time of switching to sexual
reproduction being correlated with population density. Most of the variation
for mixis initiation has either low or no heritability and is caused by
individual environmental factors.
(Institut
’’Cavanilles‘‘ de Biodiversitat i Biologia Evolutiva, Universitat de
València, Apartat 22085, E46071-València, Spain, e-mail: Eduardo.Aparici@uv.es)