Truncatella | |
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Two live individuals of Truncatella subcylindrica : a juvenile on the left, and an adult on the right | |
Scientific classification ![]() | |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Gastropoda |
Subclass: | Caenogastropoda |
Order: | Littorinimorpha |
Family: | Truncatellidae |
Subfamily: | Truncatellinae |
Genus: | Truncatella Risso, 1826 [1] |
Truncatella is a genus of very small land snails with an operculum, terrestrial gastropod mollusks in the family Truncatellidae. These small and minute snails live on land, very close to seawater. They walk with a strange looping action, and the adults have truncated shells. Many of the species are small enough to be considered micromollusks.
Truncatella is the type genus of the family Truncatellidae. [2]
This genus occurs in tropical and subtropical areas. The various species of Truncatella are pantropical in distribution, with a few exceptions such as Truncatella truncatula and Truncatella subcylindrica .
Most of the species in this genus live in a habitat that is neither fully terrestrial nor fully marine: they live under plant debris near high tide level, where they are occasionally wetted with seawater by waves. A small minority of the species are fully terrestrial.
These small snails are typically found associated with drifts of plant material, where their eggs are deposited. [3]
The adaptations of these land snails to the terrestrial environment are not so perfect as they are in the more usual pulmonate land snails, and their terrestrial adaptations may in fact be comparatively recent. [4]
The genus Truncatella was erected by Antoine Risso (Risso, 1826) [1] for T. costulata (now T. subcylindrica), which is the type species for this genus.
There are several genera within the Truncatellidae, but the eponymous genus Truncatella is the largest (in terms of number of species); other genera in the family are Geomelania , Taheitia , and Blandiella. [5] [6] [7]
There are approximately 30 species in the genus Truncatella, including:
As implied by the name, these snails are notable for the way they modify their elongated shells as they mature, breaking off several of the apical whorls, and forming a relatively smooth seal for the remainder of the shell.
The method of locomotion used by Truncatella is unusual. [34] Instead of gliding over a slime trail using minute waves in its foot, Truncatella uses a very large and muscular proboscis to reach ahead and grasp a surface, at which point the small foot releases its hold and the proboscis contracts to pull the animal forward, after which the entire procedure is usually repeated. [35]
The Clionidae are a family of sea angels, which are a group of pelagic marine gastropods.
Tegula is a genus of small to medium-sized sea snails, marine gastropod molluscs in the family Tegulidae.
The Trochidae, common name top-snails or top-shells, are a taxonomic family of very small to large sea snails, marine gastropod molluscs in the clade Vetigastropoda.
Neritidae, common name the nerites, is a taxonomic family of small to medium-sized saltwater and freshwater snails which have a gill and a distinctive operculum.
Trimusculus is a genus of medium-sized air-breathing sea snails or false limpets, marine pulmonate gastropod molluscs in the family Trimusculidae.
Hipponicidae, common name hoof shells or hoof snails, is a family of small sea snails, limpet-like marine gastropod molluscs in the superfamily Vanikoroidea.
Boonea is a small genus of small sea snails, pyramidellid gastropod mollusks.
Turritriton is a genus of medium-sized sea snails, marine gastropod molluscs in the family Cymatiidae. This is often still regarded merely as a subgenus of the genus Cymatium.
Pendromidae is a family of gastropods in the clade Vetigastropoda.
Solariellidae is a family of small sea snails, marine gastropod mollusks in the superfamily Trochoidea.
Liotiidae is a family of small sea snails, marine gastropod mollusks in the clade Vetigastropoda.
Crepidula, commonly known as the slipper snails, slipper limpets, or slipper shells, is a genus of sea snails, marine gastropod mollusks in the family Calyptraeidae. This family includes the slipper snails (Crepidula), hat snails (Calyptraea), spiny slipper snails (Bostrycapulus), and cup-and-saucer snails (Crucibulum) as well as Crepipatella, Siphopatella, Grandicrepidula, and Maoricrypta.
Bittium is a genus of very small sea snails, marine gastropod molluscs in the family Cerithiidae, the horn snails.
Heleobia is a genus of small freshwater and brackish water snails with a gill and an operculum, aquatic gastropod mollusks in the family Cochliopidae and the superfamily Truncatelloidea.
Bathysciadium is a genus of sea snails, deep-sea limpets, marine gastropod mollusks in the family Bathysciadiidae.
Ebala is a genus of sea snails, marine gastropod mollusks in the subfamily Ebalinae, family Murchisonellidae.
Toledonia is a genus of sea snails, marine gastropod molluscs in the family Cylichnidae.
Crenella is a genus of bean mussels in the family Mytilidae.
Lomanotus is a genus of sea slugs, marine gastropod mollusks in the family Lomanotidae.
Ciliatovelutina is a genus of small sea snails, marine gastropod mollusks in the family Velutinidae.
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