The Ennerdale black pearl is a rare black pearl formed in freshwater pearl mussels found on stretches of the Ehen and Irt rivers in the English county of Cumbria. [1] [2]
The pearls were probably known as far back as Roman times. Both Tacitus and Bede mention British pearls, and William Camden says of the Irt "In this brook the shell-fish , eagerly sucking in the dew, conceive and bring forth pearls, or (to use the Poet’s word) shell-berries. These the inhabitants gather up at low water and the jewellers buy them." In about 1695, a company was formed to search for pearls in the Irt, and Thomas Patrick of Ennerdale is said to have employed people to gather the pearls. [3]
In recent times, freshwater mussel populations have been affected by several issues, including wildlife crime, habitat degradation and declining water quality. Between 2015 and 2018, the West Cumbria Rivers Trust carried out conservation work on the River Irt to try and protect the habitat and prevent the complete eradication of the freshwater mussel from the river. [2]
A pearl is a hard, glistening object produced within the soft tissue of a living shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carbonate in minute crystalline form, which has deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes, known as baroque pearls, can occur. The finest quality of natural pearls have been highly valued as gemstones and objects of beauty for many centuries. Because of this, pearl has become a metaphor for something rare, fine, admirable and valuable.
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.
A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer usually created by an animal or organism that lives in the sea. Most seashells are made by mollusks, such as snails, clams, and oysters to protect their soft insides. Empty seashells are often found washed up on beaches by beachcombers. The shells are empty because the animal has died and the soft parts have decomposed or been eaten by another animal.
Mussel is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.
Cultured pearls are pearls which are formed within a cultured pearl sac with human intervention in the interior of productive living molluscs in a variety of conditions depending upon the mollusc and the goals. Having the same material as natural pearls, cultured pearls can be cultivated in seawater or freshwater bodies. Over 95% of the pearls available on the market are cultured pearls.
Ennerdale Water is the most westerly lake in the Lake District National Park in Cumbria, England. It is a glacial lake, with a maximum depth of 150 feet, and is 1⁄2 to 1 mile wide and 2+1⁄2 miles long.
Black Pearl or Black Pearls may refer to:
The quagga mussel is a species of freshwater mussel, an aquatic bivalve mollusk in the family Dreissenidae. It has an average lifespan of 3 to 5 years.
The River Irt is a river in the county of Cumbria in northern England. It flows for approximately 22 kilometres (14 mi) from its source in Wast Water to its estuary at Ravenglass.
The River Ehen is a river in Cumbria, England.
Ennerdale is a valley in Cumbria, England. Ennerdale Water, fed by the River Liza, is the most westerly lake in the Lake District National Park.
The freshwater pearl mussel is an endangered species of freshwater mussel, an aquatic bivalve mollusc in the family Margaritiferidae.
Unionida is a monophyletic order of freshwater mussels, aquatic bivalve molluscs. The order includes most of the larger freshwater mussels, including the freshwater pearl mussels. The most common families are the Unionidae and the Margaritiferidae. All have in common a larval stage that is temporarily parasitic on fish, nacreous shells, high in organic matter, that may crack upon drying out, and siphons too short to permit the animal to live deeply buried in sediment.
Cultured freshwater pearls are pearls that are farmed and created using freshwater mussels. These pearls are produced in Japan and the United States on a limited scale, but are now almost exclusively produced in China. The U.S. Federal Trade Commission requires that farmed freshwater pearls be referred to as "freshwater cultured pearls" in commerce. Quality of cultured freshwater pearls is evaluated through a grading system of a series of A values, based on luster, shape, surface, colour and matching.
Ellipsaria lineolata is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. This is the sole species in the monotypic genus Ellipsaria . This species is native to the drainage systems of the Mississippi River, the Mobile River, the Tennessee River, and the Cumberland River in the United States. It exists in the midwestern United States, and has also been observed in the east coast and as far south as the Gulf of Mexico. The common name of Ellipsaria lineolata is the Butterfly Mussel.
Lampsilis rafinesqueana, the Neosho mucket or Neosho pearly mussel, is a species of North American freshwater mussel endemic to Arkansas, Oklahoma, Illinois, Missouri and Kansas.
Theliderma intermedia, the Cumberland monkeyface pearly mussel or Cumberland monkeyface, is a species of freshwater mussel in the family Unionidae, the river mussels. This aquatic bivalve mollusk is native to Tennessee and Virginia in the United States. Historically widespread in the upper Tennessee River system, it populations have been reduced by habitat destruction and pollution. It now only occurs in two tributaries: the Duck and Powell Rivers. It is a federally listed endangered species.
Freshwater bivalves are one kind of freshwater mollusc, along with freshwater snails. They are bivalves that live in fresh water as opposed to salt water, which is the main habitat type for bivalves.
Aquaculture in the United Kingdom is dominated by salmon farming, then by mussel production with trout being the third most important enterprise. Aquaculture in the United Kingdom represents a significant business for the UK, producing over 200,000 tonnes of fish whilst earning over £700 million in 2012 (€793 million).
Cyrtonaias tampicoensis is a freshwater bivalve mollusc belonging to the family Unionidae.