THE VARIED ROLES OF SNAILS - National Universities Commission

oth of a direct and an indirect nature. Studies show that
snails have distributional patterns in nature which
strongly correlate with the distribution of specific
aquatic macrophytes for freshwater species (Pimentel
and white, 1959; Sturrock, 1974). It has also been found
that the relationship between snails and plants are often
mutualistic deriving a lot of benefits both ways. The
chemicals produced by plants often attract snails while
the snails themselves develop strategies for locating and
exploiting the plant species. It is now known that plants
derive two major benefits from being eaten by the
snails (especially dead plant materials) namely:
(i) Removal of the dead tissues minimizes the risks of
living tissues becoming invaded by pathogens and
damaged by toxins.
(ii) The consumption of the material by snails increases
the turnover rate of potentially growth limiting
inorganic and organic nutrients for the plants.
In further understanding the ecology of snails, the
quantitative parameters which determine the interactions
between the snails and the non living components of their
environment are important to be known. These interactions
determine the number of species available in the given
habitat at any given time.
Each species of snail in each habitat is known to be
distributed according to the resource patterns in the
environment. Thus each habitat has a theoretical maximum
number of individuals that it can support a phenomenon
referred to earlier as the carrying capacity of the habitat.
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