6 research outputs found
Intraspecific selectivity, compensatory feeding and flexible homeostasis in the phagotrophic flagellate Oxyrrhis marina: three ways to handle food quality fluctuations
The phagotrophic flagellate Oxyrrhis marina
shows a strong stoichiometric plasticity when fed
differently grown Rhodomonas salina. We tested
whether differently pre-conditioned O. marina displayed
selective feeding behaviour from a mixture of
nitrogen and phosphorus depleted R. salina. We
observed selective feeding of O. marina, always
selecting phosphorus rich R. salina independent of
the pre-conditioning of the protists. In a second
experiment, O. marina was again pre-conditioned
either with nitrogen- or phosphorus-depleted R. salina
and was refed with either of the differently limited R.
salina in single food treatments (not in a mixture). The
phagotrophic flagellate displayed compensatory feeding
which means that O. marina feed more on the food
source which they were not given before. Due to its
stoichiometric plasticity, O. marina might handle bad
quality food by following the stoichiometry of its prey
and additionally by active selective feeding towards
P-rich algae to enhance growth. Post-ingestion selection
might as well be an important feature which
means that ingested elements in excess are quickly
excreted and scarce elements are ingested through
accelerated food uptake