Did you know snails can carry up to ten times their own body weight? (Bourquin, 2000).


Inflectarius edentatus is an air-breathing, terrestrial snail living throughout parts of North America. Like any other organism, Inflectarius edentatus contain numerous morphological and physiological adaptations, ranging from those of structural, respiratory and sensory adaptations. However, with little research known about the specific evolutionary alterations I. edentatus has undergone, much of the following adaptations listed below are integrated within Gastropoda, the class containing Inflectarius edentatus, as well as Pulmonata, the subclass containing Inflectarius edentatus.

One of the most noticeable adaptations within the Class Gastropoda can be seen in the evolutionary change of the shell structure. Once coiled in a single, flat plane, the shell was symmetrical with each coil lying flat on top of the other (Bourquin, 2000). This created problems for early gastropods because the symmetrical coils were not very condensed and the diameters of some gastropods grew to be very large and heavy in structure, making it difficult for locomotion purposes (Bourquin, 2000). In order to solve this problem, gastropods experienced a significant change in structure with the 180 degree twisting of the shell called torsion (Bourquin, 2000). The 180 degree twisting of the shell solved the issue of balance and weight distribution by laying each coil around a central axis, termed a columella, and shifting these coils on a spirally upward slant. With the shell situated diagonally, the snails could now move around with greater simplicity and speed (Bourquin, 2000).

As pulmonates, otherwise known as air-breathing land snails, Inflectarius edentatus may also face the vast problem of desiccation, or dehydration, especially in very dry and arid conditions (What-when-how, 2012).  Fortunately, pulmonates have undergone multiple adaptations in order to avoid and protect against desiccation, the first being the operculum (Bourquin, 2000). The operculum is a flat, outer protective structure that is attached to the pulmonate’s shell, closing over the aperture (Bourquin, 2000). It is described almost like a trap door that snails pull over their opening in order to avoid dehydration or harsh winter months (Bourquin, 2000).  Another adaptation aiding in the protection against desiccation is termed the epiphragm. In arid conditions, pulmonates retreat into their shell and secrete the epiphragm (What-when-how, 2012). The epiphragm covering consists of either mucus or calcareous materials (Thorp, 2009). Pulmonates also adapt to dehydration and water loss through their excretory systems where they transform nitrogenous wastes to uric acid (Klappenbach, 2012). This uric acid is then released as solid crystals instead of a liquid, water-bearing urine, therefore avoiding water loss (Klappenbach, 2012).

Through the evolutionary time scale, Class Gastropoda evolved into the Subclass Pulmonata, transforming their gills into air-breathing lungs in order to prepare for a unique life on land (Kerrie, 2010). The lung, located within the mantle cavity of the snail, is highly vascularized, full of blood vessels in order to take in oxygen through the lung tissues and give up carbon dioxide (Bourquin, 2000). Respiration occurs when the mantle cavity muscles tighten and flatten in order to facilitate air flow in and out of the pneumostome or breathing hole (Klappenbach, 2012).

Some aquatic snails were originally air-breathing pulmonates that returned to a fresh-water environment later on in life (Bourquin, 2000), therefore resulting in a few more respiratory adaptations. While some pulmonates chose to move out of an aquatic environment in order to obtain oxygen on land (Thorp et al., 2010), others have adapted a long siphon structure that allows snails to breathe atmospheric air underwater, as if it were a snorkel (Bourquin, 2000). Others developed a reduced mantle cavity in order to fit a secondary gill called a pseudobranch (Bourquin, 2000).

Pulmonates have also undergone a few sensory adaptations. Some pulmonates have evolved a structure close to that of a gill, called an osphradium (Bourquin, 2000). The evolution of the osphradium is not completely known by scientists, however it is often thought of to function as a sensory organ in order to identify and sense any minerals or sediments in the water that would be passed over the gills (Bourquin, 2000). The osphradium is often full of filaments or folded multiple times in order to increase the surface area for this sensory function (Bourquin, 2000). Pulmonates have also evolved an additional pair of tentacles (Bourquin, 2000). The first pair, often used for sight, is longer than the second pair, which is often used for chemoreception in snails (Bourquin, 2000). The second pair of tentacles are also knobbed in order to increase surface area for sensory purposes (Bourquin, 2000).


Now let's take a look into the nutrition of Inflectarius edentatus.