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

Māori language Māori (), or ('the Māori language'), also known as ('the language'), is an Eastern Polynesian language spoken by the Māori people, the indigenous population of mainland New Zealand. Closely related to Cook Islands Māori, Tuamotuan, and ...

or mud-flat snail in

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ...

) is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

of air-breathing

snail 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 ...

with an operculum, a

pulmonate Pulmonata or pulmonates, is an informal group (previously an Order (biology), order, and before that a Class (biology), subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a Respiratory system of gastro ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusc 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 est ...

which lives in a habitat that is intermediate between the land and the sea, not entirely

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

and not entirely

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military ...

.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 ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

. 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 mud snail

Ecology

''Amphibola crenata'' is a curiosity, as it seems to represent a transitional state between

and

gastropods. The

mantle A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that. Mantle may refer to: *Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear **Mantle (vesture), an Eastern Orthodox ve ...

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

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 ...

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

Food chain

This snail is a

detritus In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts comm ...

or deposit feeder. It extracts

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

diatom A diatom ( Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising se ...

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 ...

. From Dave Robson, Auckland, NZ. - The titiko, karahue, pupu, ''Amphibola Crenata'' or mud-flat snail was plentiful in traditional times but because it took a lot of effort to extract the "meat" it was not a "staple" food of Maori. In earlier times it was preferable to travel miles by waka to collect pipi rather than walk 200m to scoop up the titko and spending a lot of effort to recover the meat. The titiko couldn't be used as a relish (kinaki) as it is a sealed unit with a hard shell and a cap (even 2) attached to its body that closes up and is difficult to remove. The only way in traditional times to remove the meat was to either smash the whole shell or to smash the top end and suck-out the soft contents. 25 years ago I was with a group of archaeologists near my papakainga (village) Maramarahi near Thames, NZ where they were explaining to me what a shell midden was. They said this is what your people were eating hundreds of years ago. I noticed that there were only a handful of Titiko in the midden even though there were tonnes readily available nearby. In comparison, there were hundreds of pipi and cockle shells. Over the next 25 years I asked every archaeologists and read heaps of archaeological reports/assessments as to why there were few Titiko in the midden. Their views is that it was a seasonal harvest, pollution had affected their habitats, not tasty, at least some acknowledged the difficulty to recover the meat. In the late 1950s and early 1960s I recall waiting for the time of the spring tide (3am low tide) and either wander to the mud-flats to pick titiko or cycle to the coast to pick pipi's. We would sweep and gather the titiko up with a branch, put then in a flax kete, wash/shake them in the incoming tide and then into a pot at home, boiled, then out would come the safety pin and titiko on hot fried bread and butter - only a delightful memory. It was only recently that I knew the full answer. It was the availability of the standard safety pin which were being used for tying up babies nappies. We only had one safety pin but it was an ideal tool – it had the perfect bend to access the Titiko cap/s and it had a sustained sharp point to pierce the cap/s and to pull out the tasty morsel including its tasty and chewy head and tastier entrails from the apex. Unfortunately I haven't had a meal of Titiko since 1963 and over the last 25 years during my travels all over NZ I have not seen a mature Titiko. I usually ask the old people I meet in my travel about the Titiko and they tell me the same story – they are small ones (10mm) around but no mature sized ones (25mm) ideal for eating. Apparently the Titiko, karahue, pupu, amphibola crenata is not a threatened species but unfortunately the mature ones certainly are.

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