Sydney rock oyster
Encyclopedia
The Sydney rock oyster, Saccostrea glomerata, formerly known as Saccostrea commercialis, is an oyster
species endemic to Australia
and New Zealand
. In Australia it is found in bays, inlets and sheltered estuaries from Wingan Inlet
in eastern Victoria
, along the east coast of New South Wales
and up to Hervey Bay Queensland
., around northern Australia and down the west coast to Shark Bay
in Western Australia
. There is also a small introduced population on Flinders Island
, in Bass Strait
, Tasmania
and in Albany on the south west coast of Western Australia
, where they are farmed. In New Zealand, where the species is not farmed, it is known as the New Zealand rock oyster. The Sydney rock oyster is closely related to Saccostrea cucullata, or hooded oyster, which is common on Indo-Pacific rocky shores.
Sydney rock oysters are capable of tolerating a wide range of salinities (halotolerant). They are usually found in the intertidal zone to 3 metres below the low water mark.
e. The larvae swim in estuarine and coastal waters for up to 3 weeks, during which time they develop transparent shells and a retractable foot. The larvae then settle on a clean substrate using the foot to find a suitable site. The foot is resorbed once the larva is attached. The shell darkens and the small animal takes on the appearance of an adult oyster.
Growth rates vary with local conditions, but they generally reach 50 g in 3 years. Sydney rock oysters may change sex during life. Many start out as males and later change to females. About 60% of prime eating oysters are female. Selective breeding has reduced the time to market size from 3 to 2 years. There has also been great success in selection for disease resistance to two protozoan diseases of oysters, namely, QX disease Marteilia sydneyi and winter mortality Bonamia roughleyi.
Oysters are filter feeders, straining planktonic algae from the water. Birds, fish, stingray
s, mud crab
s and starfish all eat Sydney rock oysters, with the Australian Pied Oystercatcher being particularly fond of them.
. The industry produces a gourmet product and provides employment in isolated coastal communities. In Australia, oysters in peak meat condition (i.e. spawning condition) are preferred for the half-shell trade.
Oyster
The word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified....
species endemic to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. In Australia it is found in bays, inlets and sheltered estuaries from Wingan Inlet
Wingan Inlet
Wingan Inlet is an inlet within the Croajingolong National Park, in East Gippsland, Victoria, Australia. It features a ranger-managed camping ground, about an hour's drive from the nearest town, Cann River, along a notoriously rough stretch of dirt road...
in eastern Victoria
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....
, along the east coast of New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
and up to Hervey Bay Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
., around northern Australia and down the west coast to Shark Bay
Shark Bay
Shark Bay is a World Heritage listed bay in Western Australia. The term may also refer to:* the locality of Shark Bay, now known as Denham* Shark Bay Marine Park* Shark Bay , a shark exhibit at Sea World, Gold Coast, Australia* Shire of Shark Bay...
in Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
. There is also a small introduced population on Flinders Island
Flinders Island
Flinders Island may refer to:In Australia:* Flinders Island , in the Furneaux Group, is the largest and best known* Flinders Island * Flinders Island , in the Investigator Group* Flinders Island...
, in Bass Strait
Bass Strait
Bass Strait is a sea strait separating Tasmania from the south of the Australian mainland, specifically the state of Victoria.-Extent:The International Hydrographic Organization defines the limits of the Bass Strait as follows:...
, Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
and in Albany on the south west coast of Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
, where they are farmed. In New Zealand, where the species is not farmed, it is known as the New Zealand rock oyster. The Sydney rock oyster is closely related to Saccostrea cucullata, or hooded oyster, which is common on Indo-Pacific rocky shores.
Sydney rock oysters are capable of tolerating a wide range of salinities (halotolerant). They are usually found in the intertidal zone to 3 metres below the low water mark.
Breeding
Sydney rock oysters are "broadcast spawners", that is, eggs and sperm are released into open water where fertilisation occurs. Within hours of fertilisation the eggs develop into free swimming planktonic larvaLarva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e. The larvae swim in estuarine and coastal waters for up to 3 weeks, during which time they develop transparent shells and a retractable foot. The larvae then settle on a clean substrate using the foot to find a suitable site. The foot is resorbed once the larva is attached. The shell darkens and the small animal takes on the appearance of an adult oyster.
Growth rates vary with local conditions, but they generally reach 50 g in 3 years. Sydney rock oysters may change sex during life. Many start out as males and later change to females. About 60% of prime eating oysters are female. Selective breeding has reduced the time to market size from 3 to 2 years. There has also been great success in selection for disease resistance to two protozoan diseases of oysters, namely, QX disease Marteilia sydneyi and winter mortality Bonamia roughleyi.
Oysters are filter feeders, straining planktonic algae from the water. Birds, fish, stingray
Stingray
The stingrays are a group of rays, which are cartilaginous fishes related to sharks. They are classified in the suborder Myliobatoidei of the order Myliobatiformes, and consist of eight families: Hexatrygonidae , Plesiobatidae , Urolophidae , Urotrygonidae , Dasyatidae , Potamotrygonidae The...
s, mud crab
Mud crab
Mud crab may refer to any crab that lives in or near mud, such as:*Scylla serrata, also called mangrove crab and black crab.*Scylla tranquebarica, another variety of the mangrove crab.*Scylla paramamosain...
s and starfish all eat Sydney rock oysters, with the Australian Pied Oystercatcher being particularly fond of them.
Commercial industry
There is a substantial commercial oyster farming industry in New South Wales and southern Queensland and a small emerging industry in Albany, Western AustraliaAlbany, Western Australia
Albany is a port city in the Great Southern region of Western Australia, some 418 km SE of Perth, the state capital. As of 2009, Albany's population was estimated at 33,600, making it the 6th-largest city in the state....
. The industry produces a gourmet product and provides employment in isolated coastal communities. In Australia, oysters in peak meat condition (i.e. spawning condition) are preferred for the half-shell trade.