Photo courtesy of Bumblebee.orgGastropoda have evolved to their various environments and have made many adaptations that have allowed them to not only survive, but to flourish into some of the most successful groups of the animal kingdom (Hickman et al., 2009).

The Radula:
    The Majority of land snails are herbivores and feed on fungi or plant life: such as bark or leaf litter (Dourson, 2010). In order to feed these snails have developed a structure called a radula that they use to feed (Gillis, 2012). The snails use this to scrape of bits of food into their mouth to be ingested (Gillis, 2012)

Calcium Carbonate Shell:
    Gastropods have a fleshy body that is food for the vast majority of other organisms (Dourson, 2010). They make their protective shell from calcium carbonate and is excreted by the mantle of the snail (Dourson, 2010).

    Most modern day snails have the anus located by the head, but this wasn't always the case, before the evolution of torsion the mouth and the anus were on opposite sides of the shell (Gillis, 2012). This required two opening of the protective casing of the shell, leaving the snail more vulnerable to predation (Gillis, 2012). The 180 degree twist, torsion", helps the snail survive because now it only only has one opening to protect (Gillis, 2012). Having the anus this close to the head could cause some problems while feeding, so the snails simply do excrete their wastes when they eat (Gillis, 2012).

    Snails are remarkably slow, with the fastest species moving at a max rate of about 55 yards/hour (BioExpedition). It is quite possible that they may not find another mate during their lifetime and this fact was what makes their hermaphroditic nature so important (Hickman et al., 2009). If a snail doesn't meet a mate, they can self fertilize, keeping their lineage going until they meet a mate, where they act as both female and male to make the most out of each encounter. (Hickman et al., 2009).

Oxygen Breathing Lung:
    The Patera laevior, and all other land snails, have converted their mantle into a vascular, air breathing lung (Hickman et al., 2009). The opening that allows them to breathe air is located on the side of the mantle and is called a pneomostome (Gillis, 2012).

Photo courtesy of ZipcodeZooDirect Life-style:
    When the snails first moved to land, they made another very important adaptation, the direct life-style (Hickman et al., 2009). This means that the snails lost their trocophore larval stage and give birth to infant adult staged snails (Hickman et al., 2009). The figure to the right shows that trocophore stage that was given up, courtesy of ZipcodeZoo.


Learn about Nutrition