Razor shell | |
---|---|
![]() | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Bivalvia |
Order: | Adapedonta |
Superfamily: | Solenoidea |
Family: | Pharidae |
Genus: | Ensis |
Species: | E. magnus |
Binomial name | |
Ensis magnus Schumacher, 1817 | |
Synonyms [1] | |
|
The razor shell, Ensis magnus, also called razor clam, razor fish [2] or spoot (colloquially), is a bivalve of the family Pharidae. It is found on sandy beaches in Canada and northern Europe (south to the Bay of Biscay) .
In some locations, the common name "razor shell" is also used to refer to members of the family Solenidae, including species of the genera Ensis and Solen , [3] by some taxonomic classifications which include the family Pharidae within the family Solenidae. It prefers coarser sand than its relatives E. ensis and E. siliqua .
It is known for its elongated, rectangular shape, which presents a similarity to the straight razor, hence its name. The razor shell has been known to reach 23 centimetres (9 in) [4] in length. The dorsal margin is straight while the ventral margin is curved. It can easily be confused with the slightly shorter 15 centimetres (6 in) and more curved E. ensis (in which both front and back are curved in parallel).
Razor shells have a fragile shell, with open ends. The shell is smooth on the outside and whitish in color, with vertical and horizontal reddish-brown or purplish-brown markings separated by a diagonal line. The periostracum is olive-green. The inner surface is white with a purple tinge and the foot is creamy white with brown lines.
The razor shell lives under the sand, using its powerful foot to dig to a safe depth. Its digging activity comprises six stages, repeated cyclically. A digging cycle involves integration of the muscular foot (which takes up a large part of the body) with the opening and closing of the valve and one end. The foot is inflated hydraulically, extending down into the sand and anchoring the animal. Deflation of the foot then draws the shell down. The razor shell also squirts water down into the sand, removing loose sand from its path. The foot is thought to exert a pressure of about 196 kilopascals (2.00 kgf/cm2; 28.4 psi). [5]
Its presence is revealed by a keyhole-shaped hole in the sand, made by its siphons during suspension feeding for plankton.
Razor clams can grow up to eight inches long, but are typically only four to six inches. Razor clams are filter feeders, meaning they strain food particles from the water around them. They primarily eat microscopic algae, but can also consume small crustaceans and other organic matter.
In the razor shell sexual development is highly synchronous. During the summer, they are in the sexual rest stage, and gametogenesis begins at the start of autumn. In winter and spring consecutive spawns take place, interrupted by gonadal restoration periods. [6]
Many intertidal populations of razor shell have declined as a result of overfishing; the species is in decline in many areas.
Razor shells are very sensitive to minor perturbations in, for instance, salinity and temperature. They will emerge from their burrows if salt or brine is poured in. [7]
Razor shells have been found to be vulnerable to germinoma, a variety of tumour. [6]
Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that are edible and live as infauna, spending most of their lives halfway buried in the sand of the seafloor or riverbeds. Clams have two shells of equal size connected by two adductor muscles and have a powerful burrowing foot. They live in both freshwater and marine environments; in salt water they prefer to burrow down into the mud and the turbidity of the water required varies with species and location; the greatest diversity of these is in North America.
The Pacific razor clam, Siliqua patula, is a species of large marine bivalve mollusc in the family Pharidae.
Ensis is a genus of medium-sized edible saltwater clams, littoral bivalve molluscs in the family Pharidae. Ensis, or razor clams, are known in much of Scotland as spoots, for the spouts of water they eject while burrowing into the sand, when visible at low tide. This term may also colloquially include members of the genus Solen. Ensis magnus are known as bendies due to their slightly curved shell.
The Atlantic jackknife clam, Ensis leei, also known as the bamboo clam, American jackknife clam or razor clam, is a large edible marine bivalve mollusc found on the North American Atlantic coast, from Canada to South Carolina. The species has also been introduced to Europe. The name "razor clam" is also used to refer to different species such as the Pacific razor clam or Razor shell.
Ensis minor, or the jackknife clam, is a long, smooth-shelled, burrowing clam found in the Atlantic Ocean. These clams are often collected for food. Ensis minor can grow up to 17 cm (6.7 in) in length. It is white, sometimes with reddish-brown markings.
Tresus capax is a species of saltwater clam, marine bivalve mollusk, common name the fat gaper, in the family Mactridae. It also shares the common name horse clam with Tresus nuttallii a species which is similar in morphology and lifestyle. Both species are somewhat similar to the geoduck, though smaller, with shells up to eight inches long (20 cm), weight to 3–4 lb (1.4–1.8 kg).
Solenidae, commonly called "razor shells", is a family of marine bivalve molluscs in the unassigned Euheterodonta.
The pod razor is a coastal bivalve of European waters. It is edible and has been fished commercially, especially in Portugal, Spain, Ireland and Scotland.
The dog cockle or European bittersweet is a species of marine clam, a coastal bivalve mollusc of European waters.
Pharidae is a taxonomic family of saltwater clams, marine bivalve molluscs in the order Adapedonta. This family of clams is related to the razor shells, a family which is considered to include Pharidae by some authorities.
Mya truncata, common name the blunt gaper or truncate softshell, is a species of edible saltwater clam, a marine bivalve mollusk in the family Myidae.
Ensis macha, or navaja or navajuela as it is called in Spanish, is a bivalve mollusc of the family Pharidae. It inhabits the coasts of Peru, Chile and southern Argentina. It is different from the clam colloquially known as the macha in Chile.
Ensis ensis, or the sword razor, is a razor clam, a marine bivalve mollusc in the family Pharidae. It lives buried in the sand and is found off the coasts of northwest Europe.
Fabulina fabula, the bean-like tellin, is a species of marine bivalve mollusc in the family Tellinidae. It is found off the coasts of northwest Europe, where it lives buried in sandy sediments.
Phaxas pellucidus, the transparent razor shell, is a species of marine bivalve mollusc in the family Pharidae. It is found buried in the seabed in coastal waters of northwest Europe, often in great numbers.
Lutraria lutraria is a species of large marine bivalve mollusc in the family Mactridae. Its common names include the otter shell and the common otter shell. It occurs in coastal regions of the north east Atlantic Ocean where it lives buried in the sand.
Cyrtopleura costata, or the angel wing clam, is a bivalve mollusc in the family Pholadidae. It is found in shallow parts of the northwest Atlantic and also in the North Sea of Scotland coastline and west coast of the Adriatic Sea by a remote area in the Marche region in central Italy, living in the seabed, where it digs its burrows on a very slow revolving movement for years through soft sand and mud always to a max depth of 8ft but always below 3 feet (0.91 m) at the lowest tide.
Venerupis corrugata, the pullet carpet shell, is a species of bivalve mollusc in the family Veneridae. It is found buried in the sediment on the sea bed in shallow parts of the eastern Atlantic Ocean. It is harvested for human consumption in Spain and other parts of Western Europe.
Solecurtus strigilatus, also known as the rosy razor clam, is a species of saltwater clam, a marine bivalve mollusc in the family Solecurtidae. This mollusc is a suspension feeder and can burrow with great rapidity to escape predators. It is an unusual bivalve in that its shell valves are too small to contain all the soft tissue, and the animal is unable to retreat into its shell.
Pharus legumen, is a species of bivalve mollusc commonly found burrowed in the sand on lower shores and in the shallow sublittoral.