Adaptation
Helisoma trivolvis is in the Phylum
Pulmonata. This means that it lacks gills and has lungs formed
from it's mantle cavity. Pulmonate snails are capable of
trapping an air bubble in their mantle cavity and this can
be seen as an adaptation to warmer waters, where
there isn't as much dissolved water available (Dillon,
2006). The air
in it's shell makes it buoyant, and they are able to go down
to different depths in the water by letting out gas. (Dillon, 2006). As you saw in the
habitat page, all of
the areas where these snails are found would be suitable for
this. These snails also have well developed circulatory systems
and nervous systems to be able to carry nutrients throughout the
body sufficiently. All snails have soft bodies but not all of
them have shells like Helisoma trivolvis. A shell helps
protect their body and has other important funtions as well, such as helping support the body,
and helping the snail to float. (Heckman, 2009). There are lots
of different types of snails that have shells besides the
ramshorn snail.
Next see
the nutrition page where you can
learn about other features these snails have in order to get
their food.