Nutrition:
Viviparus georgianus
acquires food by using their radula or
ciliated incurrent siphon. The radula is an organ used for
scratching and tearing different food substrates; it has chitinous
teeth that aid in the scraping of bacteria, detritus, and algae. The
radula also draws matter into the mouth, and then grinds food by
pressing it against the oral cavity. Filter-feeding is a way to
capture suspended food particles, and juvenile snails rely primarily
on this. The Banded Mystery Snail has a “food groove” that is
covered with edge of gills and cilia. The cilia draw water and
suspended matter into the groove while mucus captures the food. The
gill edges will occasionally capture food also, and it will fall
into the furrow. The particles eventually accumulate in the mucus,
and the snail orally consumes them. (Thorp and Covich, 1820; Kohl)
The Banded
Mystery Snail has a broad diet consisting of everything from live
plants to decaying matter. They graze upon green algae, filter out
floating diatoms and scavenge on decomposing plants. Viviparus
georgianus is known to feed on organic and inorganic detritus at the
bottom of slow water bodies which makes it a useful indicator of
pollution. It is used mainly to indicate the presence of excessive
fertilizer and oil. (Jokinen et. al 1982; Kipp and Benson, 2009)
Interestingly, the breakdown of food prior to consumption could
increase the protein concentration and increase nutrient content
(Browne, 1978).
Once
consumed, food is passed through the espophagous to the stomach
where digestion occurs. The stomach is located in the visceral mass,
and it is conveniently close to the digestive glands which produce
enzymes for food breakdown. After digestion occurs and nutrients are
absorbed into the blood, the body fluid flows through the body
cavity, the coelom, to strain out toxic wastes such as ammonia.
Next, the coelom is relieved of waste and water by two nephridia
that cleanse the coelomic fluid by moving waste out towards the
mantle cavity where secretion occurs. (Hickman et. al, 2009; Thorp
and Covich 1820)
Viviparus
georgianus has an open circulatory system for blood flow and oxygen
transportation. It is called an open circulatory system because the
blood will leave the snail’s vessels and enter into a large cavity.
In a closed circulatory system, blood will always remain in vessels
throughout the body. Oxygen diffuses into the blood via a gill in
the mantle cavity. Water containing oxygen passes over plates in the
gills, and blood passes over the plates in the opposite direction.
As a result, oxygen diffuses from the water to the blood where it is
pumped throughout the body via the heart. (Hickman et. al, 2009;
Thorp and Covich, 1820)