''Amphibola crenata'' (''tītiko'' in the

Māori language Māori (; endonym: 'the Māori language', commonly shortened to ) is an Eastern Polynesian languages, Eastern Polynesian language and the language of the Māori people, the indigenous population of mainland New Zealand. The southernmost membe ...

or mud-flat snail in English) is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of air-breathing

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

with an operculum, a

pulmonate Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group inclu ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

which lives in a habitat that is intermediate between the land and the sea, not entirely terrestrial and not entirely marine.Rosenberg, G. (2011). Amphibola crenata (Gmelin, 1791). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=590660 on 2012-04-06 This is not a true land snail, but it is also not a true sea snail. Unlike almost all other snails that have opercula, this species breathes air. It is common in

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

. Powell A. W. B. (1979). William Collins Publishers Ltd, Auckland, New Zealand,

Description

The thick shell of this species is about 20 mm in size. File:Amphibola crenata 2.JPG, A shell of ''Amphibola crenata'' File:Amphibola crenata (underside) 2.JPG, A shell of ''Amphibola crenata'', underside view

Ecology

''Amphibola crenata'' is a curiosity, as it seems to represent a transitional state between marine and terrestrial gastropods. The mantle is employed as a lung, and therefore immersion of the animal in sea water is of secondary importance, and occurs for not more than an hour at each high tide. This is one of very few air-breathing marine snails with an operculum and a

veliger A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells. Description The veliger is the characteristic larva of the gastropod, bivalve and scaphopod taxono ...

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

Food chain

This snail is a

detritus In biology, detritus ( or ) is organic matter made up of the decomposition, decomposing remains of organisms and plants, and also of feces. Detritus usually hosts communities of microorganisms that colonize and decomposition, decompose (Reminera ...

or deposit feeder. It extracts

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

diatom A diatom (Neo-Latin ''diatoma'') is any member of a large group comprising several Genus, genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of Earth's B ...

s and decomposing matter from the surface sand. It egests the sand and a slimy secretion that is a rich source of food for bacteria.

Human use

In the past this species was an important food for the

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the Co ...

References

* Rosenberg, G. 1992. ''Encyclopedia of Seashells''. Dorset: New York. 224 pp. page(s): 125 * Golding R.E., Ponder W.F. & Byrne M. 2007. ''Taxonomy and anatomy of Amphiboloidea (Gastropoda: Heterobranchia: Archaeopulmonata)''. Zootaxa 1476: 1-50 page(s): 7

External links

1966 Te Ara encyclopedia entry
{{Taxonbar, from=Q4748206 Gastropods of New Zealand Amphibolidae Gastropods described in 1791 Taxa named by Johann Friedrich Gmelin