Truncatellidae, common name the "looping snails", is a

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

of small amphibious

snails A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gastro ...

, with

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

s and an operculum, semi-marine gastropod

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

s or micromollusks.

Shell description

This family of snails have small

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

s which lose their apical

whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

as they continue to grow, giving the shells a truncated and cylindrical appearance.

Subfamilies

The family Truncatellidae consists of two subfamilies (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005): * subfamily Truncatellinae Gray, 1840 * subfamily Geomelaniinae Kobelt & Möllendorff, 1897Kobelt & Möllendorff (1897). '' Nachrichtsblatt der Deutschen Malakozoologischen Gesellschaft'' 29(5-6): 74.

Genera

Genera within the family Truncatellidae include: Truncatellinae * '' Truncatella'' Risso, 1826"Mollusca"
. Diversidad Biológica Cubana, accessed 23 March 2011. - type genus of the family Truncatellidae Geomelaniinae * '' Geomelania'' L. Pfeiffer, 1845 - type genus of the subfamily Geomelaniinae subfamily ? * †'' Nystia'' * '' Taheitia'' Adams, 1863

Habitat

Snails in this family are found in marine coastal environments, near or just above the high tide line on stones and pebbles, fine sediments and decomposing vegetation.

Life cycle

The sexes are separate. Fertilized eggs are laid as egg capsules, which are attached to detritus.

References

External links

Truncatellidae
on Discovery Life {{Taxonbar, from=Q7847930