External Morphology

A pitch black mantle covers most of the exterior, giving it a slug-like appearance. However, the elephant slug possesses a tough white shell often partially visible beneath the mantle. The shell is laid down by the mantle, gradually adding layers from the apex (situated at one-third of the shell length from the posterior margin) to the outermost edges, giving it a roman shield appearance. Like a number of marine gastropods, their eyes are found on raised stalks, they have a pronounced snout, they possess chemosensory tentacles, and a powerful suction 'foot' for adhering to the substrate.



    Pronounced Snout
A pronounced snout can be observed when viewing the elephant slug from underneath. This extended snout which resembles an elephants trunk may be where the name 'elephant slug' comes from. The pronounced snout which houses the animals radula enables the elephant slug to graze on algae in hard to reach places between rocks.

     Tentacles
Chemosensory tentacles in marine gastropods have been found to play a number of roles. This highly specialised appendage has been identified as useful in foraging, finding conspecifics via mucous trails and in some cases used to return to a home area. The chemical receptors are so well developed that an animal is able to distinguish directionality of conspecifics by analysing differences in mucous composition.

    Muscled Foot
Like most gastropods, the elephant snails foot is used for locomotion. This appendage is a mass of muscle and connective tissue with a broad, flat, creeping sole. In order to move, mucous is secreted by a number of glands on the foot which enables the elephant slug to glide over various substrate. During locomotion, the sole of the foot is attached firmly to the substrate, except for a wave of contracted muscle used for propulsion.

    Shell
Unlike most gastropods whose shells resemble a conical shape, the shell of the elephant slug has become secondarily symmetrical. The shield shaped shell which is low and broad has been adapted to reduce resistance to flowing water. Reduction in shell resistance allows the elephant slug to easily attach to the substrate in the high impact areas.