Margarites groenlandicus, common name

Common name

A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

 the Greenland margarite or wavy top shell, is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of sea snail

Sea snail

Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....

, a marine gastropod mollusk in the 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...

 Turbinidae

Turbinidae

Turbinidae, the turban snails, are a family of small to large marine gastropods. Turbinidae have a strong, thick calcareous operculum readily distinguishing them from the somewhat similar Trochidae or top snails, which have a corneous operculum...

, the turban snails.

There are two subspecies :

• Margarites groenlandicus groenlandicus (Gmelin, 1791)
• Margarites groenlandicus umbilicalis Broderip & Sowerby, 1829 (synonym : Margarites umbilicalis Broderip & Sowerby, 1829)

Description

The wavy top shell is thin-shelled and rather small with a maximum length of 1.9 cm (¾ inch) and a compressed spire. The color of the glossy shell is cream to brown. It contains 4-5 whorls

Whorl (mollusc)

A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

, with the body whorl the largest. The sutures are wavy. The shell is smooth or with about 12 smooth spiral ridges. The broad umbilicus is funnel-shaped. The nacre

Nacre

Nacre , also known as mother of pearl, is an organic-inorganic composite material produced by some mollusks as an inner shell layer; it is also what makes up pearls. It is very strong, resilient, and iridescent....

ous aperture

Aperture (mollusc)

The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

 is oval with the long axis inclined to the left. It is also prosocline, i.e. with the growth lines leaning forward (adapically) with respect to the direction of the cone. The outer lip is thin. The sexes are separate but seldom differ externally. They are at the same time hermaphrodite

Hermaphrodite

In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...

s but self-fertilization is prevented by anatomical mechanisms. The species is a suspension or deposit feeder.

Distribution and habitat

This species is distributed across the Northern Atlantic Ocean, Greenland, the western coast of Norway, rarely along the British coast, the Gulf of Maine to Massachusetts Bay. It can be found from near the seashore to the bathyal zone

Bathyal zone

The bathyal zone or bathypelagic – from Greek βαθύς , deep – is that part of the pelagic zone that extends from a depth of 1000 to 4000 metres below the ocean surface. It lies between the mesopelagic above, and the abyssopelagic below. The average temperature hovers at about 39°F...

.