''Polinices bifasciatus'', or two-banded
moon snail
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
, 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 appropriate s ...
of
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 esti ...
. The animal was first described to science in a work authored by English biologists
Edward Griffith and Edward Pidgeon. This was a multi-volume translation of
George Cuvier's, ''Le Règne Animal'' (1830). The Griffith and Pidgeon work went beyond translation and added a supplement that included the description of ''Polinices bifasciatus''. The description of ''Polinices bifasciatus'' is attributed to
John Edward Gray
John Edward Gray, FRS (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for ...
. It reads, in its entirety, "Pale brown, with two narrow bands".
Description
The shell is smooth. The exterior is tan or light brown with two widely-separated, narrow white bands. There are about four whorls and a low spire. The shell has a large aperture. The shell is a darker brown at the inside edge of the aperture. The interior is white. The shell reaches a height of 40 mm (1.6 inches) and a diameter of 26 mm (1 inch). The
operculum is brown.
Distribution
This moon snail is found from in the eastern Pacific Ocean from the
Gulf of California
The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja Ca ...
to
Panama
Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Cos ...
. It has not been documented on the west coast of the
Baja Peninsula. It is a shallow water species found in the
intertidal zone
The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...
to 3 meters (10 feet) deep on sand and mud flats.
Life history
Like most of the moon snails, ''Polinices bifasciatus'' produces a
sand collar to lay its eggs during breeding season.
This moon snail preys on small
bivalves
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...
. It is actively mobile, hunting on soft seabeds for buried clams. It uses an abrasive appendage called a
radula
The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...
to drill into the shells of small clams. Once inside, it secretes digestive fluids and then feeds on the clam slurry that results.
References
{{Taxonbar, from=Q6781704
Naticidae
Gastropods described in 1833
Taxa named by John Edward Gray