Assimineidae is a family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of minute snail

Snail

Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...

s with an operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

 that live in saltwater, freshwater or on the land; they are mostly aquatic

Aquatic animal

An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 gastropod mollusks or micromollusk

Micromollusk

A micromollusk is a descriptive term for a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also reach adult size at very small...

s, in the clade Littorinimorpha

Littorinimorpha

Littorinimorpha is a large clade of gastropods within Hypsogastropoda consisting primarily of marine species, but also aquatic and terrestrial species as well....

.

Ecology

Various species in this family occur in estuarine habitats, in salt marsh

Salt marsh

A salt marsh is an environment in the upper coastal intertidal zone between land and salt water or brackish water, it is dominated by dense stands of halophytic plants such as herbs, grasses, or low shrubs. These plants are terrestrial in origin and are essential to the stability of the salt marsh...

es and in freshwater. Some are terrestrial or amphibious

Amphibious

Amphibious means able to use either land or water. In particular it may refer to:*Amphibious warfare, warfare carried out on both land and water*Amphibians, vertebrate animals of the Class Amphibia...

.

Description

The shell

Gastropod shell

The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

 is small to medium large, more or less egg-conelike shaped. The apertural margin is simple. The operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

 is in most cases horny.

They are characterized by rudimentary cephalic tentacles, a trunklike snout

Snout

The snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...

, a foot with a groove and rudimentary to absent ctenidium

Ctenidium

Ctenidium may be:* Ctenidium , , a comb-like gill, part of the respiratory system of gastropods and bivalves* Ctenidium, , a row of peg-like spines in some insects...

 (a comb-like respiratory apparatus).

Taxonomy

The following three subfamilies have been recognized in the taxonomy of Bouchet & Rocroi (2005)

Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)

The taxonomy of the Gastropoda as it was revised by Philippe Bouchet and Jean-Pierre Rocroi is currently the most up-to-date overall system for classifying gastropod mollusks...

:

• Subfamily Assimineinae H. Adams & A. Adams, 1856 - synonym: Synceratidae Bartsch, 1920
• Subfamily Ekadantinae Thiele, 1929 - synonyms: Paludinellidae Kobelt, 1878 (n.a.); Cyclotropidae Iredale, 1941
• Subfamily Omphalotropidinae Thiele, 1927 - Realiinae L. Pfeiffer, 1853 (inv.); Adelomorphinae Kobelt, 1906 (inv.); Garrettiinae Kobelt, 1906; Pseudocyclotini Thiele, 1929; Thaanumellinae Clench, 1946; Tutuilanidae Hubendick, 1952

Genera

Genera in the family Assimineidae include:

subfamily Assimineinae

• Assiminea
  Assiminea
  Assiminea is a genus of minute, salt marsh snails with an operculum, aquatic gastropod mollusks, or micromollusks, in the family Assimineidae.-Distribution and habitat:These snails are distributed worldwide...
  
  Fleming, 1828 - type genus of Assimineidae, synonym: Assiminia

subfamily Ekadantinae

• Paludinella
  Paludinella
  Paludinella is a genus of minute salt marsh snails with an operculum, aquatic gastropod mollusks or micromollusks, in the family Assimineidae.-Species:The genus Paludinella contains the following species:* Paludinella conica...
  
  Pfeiffer, 1841

subfamily Omphalotropidinae

• Omphalotropis
  Omphalotropis
  Omphalotropis is a genus of minute salt marsh snails with an operculum, terrestrial gastropod mollusks in the family Assimineidae.-Species:Species within the genus Omphalotropis include:* Omphalotropis albocarinata...
  
  Pfeiffer, 1851 - type genus of the subfamily Omphalotropidinae
• Garrettia Paetel, 1873
• Pseudocyclotus Thiele, 1894
• Thaanumella
  Thaanumella
  Thaanumella is a genus of gastropod in the Assimineidae family.It contains the following species:* Thaanumella angulosa* Thaanumella cookei...
  
  Clench, 1946

subfamily ?

• Acmella Blanford, 1869
• Afroassiminea
• Angustassiminea Habe, 1943
• Austroassiminea
  Austroassiminea
  Austroassiminea is a genus of minute, salt marsh snails with an operculum, aquatic gastropod mollusks, or micromollusks, in the family Assimineidae....
  
  Solem, Girardi, Slack-Smith & Kendrick 1982
• Balambania Crosse, 1891
• Conacmella
  Conacmella
  Conacmella is a genus of minute, salt marsh snails with an operculum, aquatic gastropod mollusks, or micromollusks, in the family Assimineidae....
  
  
• Conassiminea
  Conassiminea
  Conassiminea is a genus of minute operculate snails, marine gastropod mollusks or micromollusks in the family Assimineidae.-Species:Species within the genus Conassiminea include:* Conassiminea studderti Fukuda & Ponder, 2006...
  
  
• Cyclomorpha Pease, 1871
• Electrina Baird, 1850
• Fijianella Cooke & Clench, 1943
• Heteropoma
  Heteropoma
  Heteropoma is a genus of minute, salt marsh snails with an operculum, aquatic gastropod mollusks, or micromollusks, in the family Assimineidae.-Species:Species in the genus Heteropoma include:* Heteropoma fulva* Heteropoma glabratum...
  
  Benson, 1856
• Kubaryia
  Kubaryia
  Kubaryia is a genus of minute, salt marsh snails with an operculum, aquatic gastropod mollusks, or micromollusks, in the family Assimineidae.-References:*...
  
  Clench, 1948
• Ponapella
  Ponapella
  Ponapella is a genus of minute snails with an operculum, aquatic gastropod mollusks in the family Assimineidae.It contains the following species:* Ponapella pihapiha...
  
  Clench, 1946
• Pseudogibbula Dautzenberg, 1890
• Quadrasiella
  Quadrasiella
  Quadrasiella is a genus of gastropod in the Assimineidae family.It contains the following species:* Quadrasiella clathrata* Quadrasiella mucronata...
  
  Moellendorff, 1894
• Rapanella Cooke & Clench, 1943
• Septariellina
• Wrayanna
  Wrayanna
  Wrayanna is a genus of minute, salt marsh snails with an operculum, aquatic gastropod mollusks, or micromollusks, in the family Assimineidae....