''Turritella communis'',

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...

the "common tower shell" 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 medium-sized

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

s with an operculum, marine

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 ...

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

s in the family

Turritellidae Turritellidae, with the common name "tower shells" or "tower snails", is a Taxonomy (biology), taxonomic family (biology), family of small- to medium-sized sea snails, marine gastropod molluscs in the Sorbeoconcha clade. They are filter feeders; ...

Distribution and habitat

This species occurs in the Eastern

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

from the

Lofoten Lofoten ( , ; ; ) is an archipelago and a Districts of Norway, traditional district in the county of Nordland, Norway. Lofoten has distinctive scenery with dramatic mountains and peaks, open sea and sheltered bays, beaches, and untouched lands. T ...

Isles south to the

Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...

and North Africa. It is rare or absent from the eastern

English Channel The English Channel, also known as the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busi ...

and the southern

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

. This tower shell can be found in the

sublittoral zone The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminated ...

to depths up to 200 m, where it is usually found burrowed in gravelly mud at an angle of about 10°. There it remains stationary for long periods. It can be locally abundant on muddy sediment in shallow waters.

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

and subfossil shells of ''Turritella communis'' have been found in

interglacial An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene i ...

strata In geology and related fields, a stratum (: strata) is a layer of Rock (geology), rock or sediment characterized by certain Lithology, lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by v ...

in the North Sea, from the

Late Pliocene Late or LATE may refer to: Everyday usage * Tardy, or late, not being on time * Late (or the late) may refer to a person who is dead Music * Late (The 77s album), ''Late'' (The 77s album), 2000 * Late (Alvin Batiste album), 1993 * Late!, a pseudo ...

to the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

Period.

Description

The tall, conical shell is brownish-yellow to white. It is sharply pointed and contains 16-20 enlarged whorls. The spiral ridges are numerous (with 3 - 6 more prominent) and may have a beaded appearance. The shell grows to a length of 3 cm and may become 1 cm wide. The angulate shell

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

is small. The outer lip is crenulate. There is no umbilicus. The concave operculum is small and circular and has numerous pinnate bristles on its edges. The snail shows white markings on the tentacles, siphon and foot. This small foot shows dark spots and streaks.

Feeding habits

''Turritella communis'' feeds on deposits through ciliary feeding. In order to prevent larger particles entering the mantle cavity, it possesses at the mantle edge a curtain of tentacles of which the larger ones are pinnate.

References

*
Michelle Carter 2008. Turritella communis. An auger shell. Marine Life Information Network

Distribution and habitat

Description

Feeding habits

References

Further reading