Ecology of planktonic rotifers at Loch Leven, Kinross-shire.
The population dynamics of rotifers in Loch Leven was studied over
a three year period (1977-1979) from samples collected at weekly
intervals. Since up to 65 per cent of the smaller rotifers may be
lost when collected with a net of 45mm mesh size, the samples were
collected by volumetric methods and concentrated by sedimentation.
Loch Leven was generally well-mixed with rotifers distributed more
or less randomly throughout the pelagic zona on most occasions.
Population densities could, therefore, be estimated from only a smal1
number of samples.
Rotifers are generally difficult to identify since little is known
of their ecology and their morphology is often strongly influenced
by environmentally induced polymorphism. In order to avoid any
major systematic misunderstanding the species list for Loch Leven is
accompanied by short descriptions of the animals with notes on the
problems of identification.
Rotifers showed a distinct pattern of seaonal succession which
appeared to be influenced, primarily, by species specific responses
to changing water temperature. Many species showed a well-defined
range of temperature preference beyond which their reproductive
success was seriously impaired .Within this range of temperature
preference, the birth rate was dependent upon water temperature and
Many rotifer species appeared to be food specialists and some
observations were made on their feeding habits. Attempts were made to
culture rotifers on various algal species in the laboratory to test
hypotheses suggested by field observtions.
The predation of rotifers by Cyclopoid copepods, the predatory
rotifer Asolanchna priodonta end larval perch is discussed, However,
little quantitative information was available and the impact of
predation on rotifer populations in Loch Leven is still unknown.