Micromollusc

Micromolluscs are not very popular as a subject of study, even among professional malacologists, primarily because these minute species can be very challenging to work with.

[1] It can often require great care, patience and persistence to find micromolluscs, sort them, store them, and identify them correctly.

Discriminating the features necessary for successful identification of micromolluscs to the species level almost always requires a stereo or dissecting microscope.

Access to a first rate scientific research library is also often necessary, since many of the popular shell identification books and field guides either omit micromolluscs completely, or only include a very few species for any particular area.

Because of all these various challenges, micromolluscs are poorly known compared to their larger relatives, and thus there are undoubtedly numerous species which have yet to be discovered and described.

The shells of the very smallest micromolluscs are less than one millimeter in adult size, and thus they are truly microscopic, smaller in fact than some sand grains.

Underwater in a marine context, for example when scuba diving, a sediment sample is often taken from areas such as the surface layer of sand under rocks, or at the edge of a coral reef.

Numerous shells of the freshwater snail Potamopyrgus antipodarum compared to an American dime , which is 18 mm in diameter
Two shells of the freshwater snail Gyraulus crista , about 2 or 3 mm in width
Six shells of the land snail Columella edentula , the scale bar is in mm
Shells of some micromolluscs: from left, Truncatella bahamensis ( holotype ), Truncatella bilabiata bilabiata , Truncatella pulchella . [ 3 ]
An exhibit at the Bailey-Matthews National Shell Museum about micromolluscs, showing some species from Sanibel, Florida