Pacific oyster

The Pacific oyster, Japanese oyster or Miyagi oyster (Crassostrea gigas), is an oyster native to the Pacific coast of Asia. It has become an introduced species in North America, Australia, Europe, and New Zealand.

Etymology

The species name comes from the Latin crass meaning "thick",ostrea meaning "oyster" and gígās meaning "giant".

Description

The shell of Crassostrea gigas varies widely with the environment where it is attached. Its large, rounded, radial folds are often extremely rough and sharp. The two valves of the shell are slightly different in size and shape, the right valve being moderately concave. Shell colour is variable, usually pale white or off-white. Mature specimens can vary from 80 mm to 400 mm long.

Ecology

Habitat

Crassostrea gigas is an estuarine species, but can also be found in intertidal and subtidal zones. They prefer to attach to hard or rocky surfaces in shallow or sheltered waters up to 40 m deep, but have been known to attach to muddy or sandy areas when the preferred habitat is scarce. The Pacific oyster can also be found on the shells of other animals. Larvae often settle on the shell of adults, and great masses of oysters can grow together to form oyster reefs. The optimum salinity for Pacific oysters is between 20 and 35 parts per thousand (ppt), and they can tolerate salinities as high as 38 ppt; at this level, however, reproduction is unlikely to occur. The Pacific oyster is also a very temperature tolerant species, as it can withstand a range from -1.8 to 35°C.

Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south and is bounded by Asia and Australia in the west and the Americas in the east.

At 165.25 million square kilometers (63.8 million square miles) in area, this largest division of the World Ocean—and, in turn, the hydrosphere—covers about 46% of the Earth's water surface and about one-third of its total surface area, making it larger than all of the Earth's land area combined.

The equator subdivides it into the North Pacific Ocean and South Pacific Ocean, with two exceptions: the Galápagos and Gilbert Islands, while straddling the equator, are deemed wholly within the South Pacific. The Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 metres (35,797 ft).

The eastern Pacific Ocean was first sighted by Europeans in the early 16th century when Spanish explorer Vasco Núñez de Balboa crossed the Isthmus of Panama in 1513 and discovered the great "southern sea" which he named Mar del Sur. The ocean's current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish circumnavigation of the world in 1521, as he encountered favourable winds on reaching the ocean. He called it Mar Pacifico, which in both Portuguese and Spanish means "peaceful sea".

Oyster

The word oyster is used as a common name for a number of different families of saltwater clams, bivalve molluscs that live in marine or brackish habitats. In some species the valves are highly calcified, and many are somewhat irregular in shape. Many, but not all, oysters are in the superfamily Ostreoidea.

Some kinds of oysters are commonly consumed by humans, cooked or raw, the latter being a delicacy. Some kinds of pearl oysters are harvested for the pearl produced within the mantle. Windowpane oysters are harvested for their translucent shells, which are used to make various kinds of decorative objects.

Etymology

First attested in English during the 14th century, the word "oyster" comes from Old French oistre, in turn from Latin ostrea, the feminine form of ostreum, which is the latinisation of the Greek ὄστρεον (ostreon), "oyster". Compare ὀστέον (osteon), "bone".

Types

True oysters

True oysters are members of the family Ostreidae. This family includes the edible oysters, which mainly belong to the genera Ostrea, Crassostrea, Ostreola, and Saccostrea. Examples include the Belon oyster, eastern oyster, Olympia oyster, Pacific oyster, and the Sydney rock oyster.

Coffin Bay

Coffin Bay (34°37′S 135°28′E / 34.617°S 135.467°E / -34.617; 135.467), originally Coffin's Bay, is a town at the southern extremity of the Eyre Peninsula, a wheat growing area of South Australia. At the 2006 census, Coffin Bay had a population of 584.

The town is situated on the western side of the southern tip of Eyre Peninsula about 46 km from Port Lincoln. The population swells during holiday seasons to more than 2,000 people due to its proximity to the Coffin Bay National Park.

It is a popular location for boating, sailing, swimming, water-skiing, skindiving and wind-surfing, as well as fishing (rock, surf, angling and boat).

Oyster farming is conducted in the quiet waters of Coffin Bay.

Coffin Bay is in the District Council of Lower Eyre Peninsula local government area, the state electoral district of Flinders and the federal Division of Grey.

History

The Parnkalla people occupied the area prior to European settlement in the 1830s.

British naval explorer Matthew Flinders named the bay on 16 February 1802 in honour of his friend Sir Isaac Coffin, who was Resident Naval Commissioner at Sheerness, where the Investigator was fitted out. The same year, French explorer Nicolas Baudin provided the alternative French name of Baie Delambre.