The Armed Snaggletooth (Gastrocopta armifera)


Compared to many other species in the genus Gastrocopta and family Vertiginidae, G. armifera is massive with a length up to 5mm and diameter of up to 2.6mm(Hubricht, 1972), it is one of the only snails of its kind that can be readily spotted and picked up in the field (Carnegie, 2011). This large size can be both beneficial and harmful to G. armifera. When plant life in its habitat is not prosperous, G. armifera can use its large size to overpower and prey on species of snail smaller than itself. However, this large size also means that G. armifera is much more visible to its predators such as salamanders and small mammals (Discover, 2011).
Much like all other species in the Class Gastropoda, G. armifera moves by sliding on its muscular foot. They creep forward by progressive waves of contraction and expansion of a ventral, muscular foot. Glands in the muscular foot secrete slimy mucus that enables them to glide over rough surfaces (Martin, 2000).

G. armifera
has an epiphragm, or a thin membrane that covers the aperture during hibernation. This epiphragm aids G. armifera in its unique and outstanding ability to supercool, more so than any other land snail species found in America (Riddle, 1988). This ability to supercool, or tolerate cold temperatures, allows G. armifera to survive harsh winters and move its northern boundary further north. In some snails, G. armifera has a secondary epiphragm that may cause its extraordinary ability to supercool, as snails with an epiphragm have a significantly higher ability to supercool than snails that do not form an epiphragm (Ansart et al, 2002).
The Armed Snaggletooth also uses a radula; a rasping, protrusible, tongue-like organ found in all mollusks except bivalves. This radula is covered with as many as 250,00 teeth that can scrape, pierce, tear, or cut particles of food. The radula may also serve as a rasping file for carrying particles in a continuous stream towards the digestive tract (Hickman et al, 2007).

Ghost Slug teeth

G. armifera, like all other species in the genus Gastrocopta have multiple projections around the shell aperturecall “lamellae”. These lamellae can be used as protection or to help prevent water loss; both things very important in smaller species of snails. The unique patterns of the lamellae in the aperture are employed to distinguish species and races within the Family Gastrocoptidae. The distinguishing pattern for the G. armifera is a total of five of these “teeth,” including a massive columellar lamella, and at top center, a bifurcate lamella formed by the joining of the angular and parietal lamellae (Carnegie, 2011).


The Empty Shell of G. armifera
(The lamellae can be clearly seen at the opening of the shell)