Nutrition
Like all other organisms, there have been several adaptations to help serve snail's nutritional needs.
Since little is known about
Patera clarki, we
will look at nutrition and digestion of
Stylommatophora in general.
Terrestrial snails diet can vary and these snails are mainly herbivores
and omnivores, but some are carnivores (Carnegie,
2012). They are
described as being “generalists” meaning they don’t have a
specific diet or food they mainly feed on (Carnegie,
2012).
Herbivorous land snails’ diet consists of algae, decomposing
matter, leaves and stems of plants, wood, bark, and fungi (Carnegie,
2012).
All terrestrial land snails possess a radula, a
membrane with teeth made of chitin, which is used to scrape food
such as algae (Carnegie, 2012).
Mackenstedt and Markel compare the teeth of the radula to those
of a shark; while the chitin teeth in front are being used and
After entering the buccal cavity, food is
begun to digest by two salivary glands, which secret mucous and
amylase (Dimitriadis, 2001).
The saliva will help remove food from the radula and help
food pass to the oesophagus (Dimitriadis,
2001). The food
will pass into the oesophagus (similar to the esophagus in
humans) and continues into the gastric pouch (stomach) where it
only spends a short amount of time before entering the digestive
gland (Dimitriadis, 2001).
Nutrients are absorbed in the digestive gland and the
wastes are sent through the intestines and out through the anus
(Dimitriadis, 2001).
In addition, terrestrial snails need to
acquire calcium for their shells; they do this by consuming soil
or rocks (Carnegie, 2012).
Snail’s shells are made of calcium carbonate, which birds
need an abundance of when breeding so they can successfully form
egg shells (Allen, 2004).
This is why birds prey on snails.
Snails have been known to build up toxic heavy metals where pollution occurs (Allen, 2004). They concentrate the metals in their bodies, some more than others depending on species and age (Rabitsch, 1996).