L. Shimek, Ph. D.
Hay, M. E., J. D. Parker, D. E. Burkepile,
C. C. Caudill, A. E. Wilson, Z. P. Hallinan, and A. D. Chequer.
2004. Mutualisms And Aquatic Community Structure: The Enemy
Of My Enemy Is My Friend. Annual Review of Ecology, Evolution,
and Systematics. 35: 175-197.
Mutualisms occur when interactions between
species produce reciprocal benefits. However, the outcome
of these interactions frequently shifts from positive, to
neutral, to negative, depending on the environmental and community
context, and indirect effects commonly produce unexpected
mutualisms that have community-wide consequences. The dynamic,
and context dependent, nature of mutualisms can transform
consumers, competitors, and parasites into mutualists, even
while they consume, compete with, or parasitize their partner
species. These dynamic, and often diffuse, mutualisms strongly
affect community organization and ecosystem processes, but
the historic focus on pairwise interactions decoupled from
their more complex community context has obscured their importance.
In aquatic systems, mutualisms commonly support ecosystem-defining
foundation species, underlie energy and nutrient dynamics
within and between ecosystems, and provide mechanisms by which
species can rapidly adjust to ecological variance. Mutualism
is as important as competition, predation, and physical disturbance
in determining community structure, and its impact needs to
be adequately incorporated into community theory.
This article is a very interesting bit
of reading and a great reference for someone wanting to learn
about the "nuts and bolts" of mutualisms,
such as how and why they occur, and the evidence for various
aspects of this category of biological interactions. The interactions
between coral reef animals and zooxanthellae are dealt with,
as well as many other types of mutualisms.