Since
1965, the trademark of the work from the laboratory
of J. Rudi Strickler has been the direct observation
of the swimming and feeding performances of small
aquatic animals. Most studies are conducted in the
laboratory using sophisticated optical equipment.
The results from this research have been astonishing
and have induced several paradigm shifts in the
perception of aquatic life and its ecology. Until
1975, for example, diapause in zooplankters was
thought of as avoiding harsh environmental conditions.
Based on studies of the predator - prey relationships
between copepods, Strickler and Twombly (1975) concluded
that diapause might also function as a predator-avoidance
adaptation. Similarly, a closer look at the feeding
mechanisms in calanoid copepods changed and advanced
our perception of the first principles involved
in the capturing of algae by aquatic herbivores
(Alcaraz et al. 1980; Koehl and Strickler 1981;
Strickler 1982, 1984, 1985).
Recently, studies of feeding performances in calanoid
copepods suspended in turbulent waters have revealed
complex relationships between the encounter rate
with food and the misinterpretation of signals perceived
by the mechanoreceptors (Costello et al. 1990; Marrase
et al. 1990). Additionally, observations of free-swimming
male and female copepods revealed the intricate
signaling of maturity and position necessary for
successful mating in copepods (Strickler 1998; Doall
et al. 1998).
Research has also focused on the mathematical treatment
of the observations. Bundy et al. (1993) observed
calanoids swimming in three-dimensional space; Keiyu
et al. (1994) introduced Artificial Intelligence
models to express the swimming paths in terms of
the underlying motivations and energetic needs and
restrictions of the animals. Cited literature and
examples of observations can be found at the web
site of the Strickler laboratory (http://www.uwm.edu/~jrs).
Two
separate views of a small fish attempting to catch
a Daphnia. WATER Institute scientists will create a 3-D
model based on these two views to learn more about
how Daphnia senses its environment.
Home