Abalone

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For other uses, see Abalone (disambiguation).

Abalone

Scientific classification

Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Orthogastropoda
Superorder:	Vetigastropoda
Superfamily:	Haliotoidea
Family:	Haliotidae Rafinesque, 1815
Genus:	Haliotis Linnaeus, 1758

Species

Many: see text.

A piece of abalone shell

The iridescent inside surface of an abalone shell

The raw meat of abalone

Abalone is the American English variant of the Spanish name Abulón used for various species of shellfish (mollusks) from the Haliotidae family (genus Haliotis). The abalones belong to the large class of gastropods (Gastropoda). There is only one genus in the family Haliotidae, and about four to seven subgenera. The taxonomy is somewhat confused. The number of species range from about 100 to about 130 species (due to the occurrence of hybrids), characterized by a richly coloured (on the inside—the outside is rough and mostly brown) shell yielding mother-of-pearl. This is also commonly called ear-shell, in Guernsey ormer (Fr. ormier, for oreille de mer), perlemoen in South Africa and pāua in New Zealand. Abalone is also prevalent in Australian and South African coastal waters and is highly valued. The muscle tissue of this mollusk is considered a delicacy in certain parts of Latin America, especially Chile, South-East and East Asia, especially in China, Japan and Korea.

Abalones are snail-like, with a distinct head at the front and a muscular foot for locomotion.

1 Distribution and characteristics
- 1.1 Abalone shell
2 Abalone diving in California
3 Abalone diving in New Zealand
4 Perlemoen diving in South Africa
5 Ormers in the Channel Islands
6 White abalone
7 List of species with common name
8 References
9 Research
10 External links

[edit] Distribution and characteristics

The Haliotid family has a worldwide distribution, along the coastal waters of every continent, except South America and the East Coast of the United States. Most abalones are found off the Southern Hemisphere coasts of New Zealand, South Africa and Australia, and Western North America and Japan in the Northern Hemisphere.

The family has unmistakable characteristics : the shell is rounded to oval, with two to three whorls, and the last one auriform, grown into a large "ear", giving rise to the common name ‘ear-shell’. The body whorl has a series of holes — four to ten depending on the species, near the anterior margin. The shell has five holes in that are used for waste effluent.

There is no operculum. The back is convex, ranging from highly arched to very flattened. These shells cling solidly with their muscular foot to rocky surfaces at sublittoral depths. The color is very variable from species to species. The inside of the shell consists of iridiscent, silvery white to green-red mother-of-pearl through to Haliotis Iris which can comprise of pinks and reds with predominant deep blues, greens and purples.

Abalones reach maturity at a small size. Their fecundity is high and increases with size (from 10,000 to 11 million eggs at a time).

The larvae feed on plankton. The adults are herbivores and feed on macroalgae, preferring red algae. Sizes vary from 20 mm (Haliotis pulcherrima) to 200 mm (or even more) (Haliotis rufescens).

[edit] Abalone shell

The shell of the abalone is known for being exceptionally strong. It is made of microscopic calcium carbonate tiles stacked like bricks. Between the layers of tiles is a sticky protein substance. When the abalone shell is struck, the tiles slide instead of shattering and the protein stretches to absorb the energy of the blow. Material scientists at the University of California, San Diego are studying the tiled structure for insight into stronger ceramic products such as body armor.^[1]

[edit] Abalone diving in California

Sport harvesting of Red Abalone is permitted with a California fishing license and an abalone stamp card. Abalone may only be taken using breath-hold techniques: freediving or shorepicking. SCUBA diving for abalone is strictly prohibited. Taking of abalone is not permitted south of the mouth of the San Francisco Bay. There is a size minimum of seven inches measured across the shell and a quantity limit of three per day and 24 per year. Abalone may only be taken in April, May, June, August, September, October and November; abalone may not be taken in July, December, January, February or March. Transportation of abalone may only legally occur while the abalone is still attached in the shell. Sale of sport obtained abalone is illegal, including the shell. Only Red Abalone may be taken; black, white, pink, and flat abalone are protected by law.

An abalone diver is normally equipped with a very thick wetsuit, including a hood, booties, and gloves. He or she would also wear a mask, snorkel, weight belt, abalone iron, and abalone gauge. It is common to take abalone in water a few inches up to 10m/28' deep; less common are freedivers who can work deeper than 10m/28'. Abalone are normally found on rocks near food sources (kelp). An abalone iron is used to pry the abalone from the rock before it can fully clamp down. Visibility is normally five to ten feet. Divers commonly dive out of boats, kayaks, tube floats or directly off the shore. An eight inch abalone is considered a good catch, a nine inch would be extremely good, and a ten inch plus (250 mm) abalone would be a trophy catch. Rock- or shore-picking is a separate method from diving where the rock picker feels underneath rocks at low tides for abalone.

There has been a trade in diving to catch abalones off parts of the United States coast from before 1939. In World War II, many of these abalone divers were recruited into the United States armed forces and trained as frogmen.

[edit] Abalone diving in New Zealand

Abalone farm

There is an extensive global black market in the collection and export of abalone meat. In New Zealand, where abalone is called pāua in the Māori language, this can be a particularly awkward problem where the right to harvest pāua can be granted legally under Māori customary rights. When such permits to harvest are abused, it is frequently difficult to police. The legal recreational daily limit is 10 pāua per diver with a minimum shell length of 125 mm. The limit is strictly enforced by roving Ministry of Fisheries officers with the backing of the police. Pāua 'poaching' is a major industry in New Zealand with many thousands being taken illegally, often undersized. Convictions have resulted in seizure of diving gear, boats and motor vehicles as well as fines and in rare cases; imprisonment. The Ministry of Fisheries expects in the year 2004/05, nearly 1000 tons of pāua will be poached, with 75% of that being undersized.[1]

Highly polished New Zealand pāua shells are extremely popular as souvenirs with their striking blue, green and purple iridescence. Transporting unprocessed abalone shells out of New Zealand is illegal.

[edit] Perlemoen diving in South Africa

The largest abalone in South Africa, the perlemoen, Haliotis midae, occurs along approximately two-thirds of the country’s coastline. Perlemoen-diving has been a recreational activity for many years, but stocks are currently being threatened by illegal commercial harvesting.

[edit] Ormers in the Channel Islands

Ormers (Haliotis tuberculata) are considered a delicacy in the Channel Islands and are pursued with great alacrity by the locals. Unfortunately, this has led to a dramatic depletion in numbers since the latter half of the 19th century, and 'ormering' is now strictly regulated in order to preserve stocks. The gathering of ormers is now restricted to a number of 'ormering tides', from the January 1 to April 30, which occur on the full or new moon and two days following. No ormers may be taken from the beach that are under 8 cm in shell length. Gatherers are not allowed to wear wetsuits or even put their heads underwater. Any breach of these laws is a criminal offence and can lead to a heavy fine. The demand for ormers is such that they led to the world's first underwater arrest, when Mr Kempthorne-Leigh of Guernsey was arrested by a police officer in full diving gear when illegally diving for ormers.

[edit] White abalone

The white version of the Abalone shell fish is sometimes confused as the only type of abalone due to the spread of western culture and because it is the most widely consumed. White abalone, Haliotis sorenseni, may have the smallest population on the West Coast of North America. It is said to have one of the most tender and flavorful meats of all the abalone species. Currently this species is being maricultured for seed to be placed in the ocean in hopes of bringing this species back to safe population levels.

Discovered in 1940, the white abalone is the deepest dwelling of eight species of California abalones, ranging from 80 to 200 feet deep. Scripps Institution of Oceanography biologists conducted surveys of white abalone deep water habitat in the early 1970’s, finding high concentrations of about one white abalone per square yard. Such densities were comparable to abundance of shallower species of abalone found in previously unfished or protected areas. Unfortunately, high demand for this species led to a “boom-and-bust” fishery that was essentially fished out in seven years.

White Abalone usually has between 3-5 open holes in its shell. The outside shell color varies anywhere between red to brown while the inside is white and pink. The shell tentacles are lacy, beige and yellow-green in color.

[edit] List of species with common name

Pink Abalone (Haliotis corrugata)

Haliotis ancile : Shield Abalone.
Haliotis aquatilis : Japanese Abalone.
Haliotis asinina : Ass’s ear Abalone.
Haliotis assimilis : Threaded Abalone.
Haliotis australis : Australian Abalone, Austral Abalone.
Haliotis brazieri : Brazier’s Abalone.
Haliotis coccoradiata : Reddish-rayed Abalone.
Haliotis conicopora : Conical Pore Abalone, Brownlip Abalone
Haliotis corrugata : Pink Abalone.
Haliotis crachedorii : Black Abalone.

White Abalone (Haliotis sorenseni)

Haliotis crebrisculpta : Close Sculptures Abalone.
Haliotis cyclobates : Whirling Abalone.
Haliotis dalli : Dall’s Abalone.
Haliotis discus : Disk Abalone.
Haliotis diversicolor : Variously Coloured Abalone.
Haliotis dohrniana : Dhorn’s Abalone.
Haliotis elegans : Elegant Abalone.
Haliotis emmae : Emma’s Abalone.
Haliotis ethologus : Mimic Abalone.
Haliotis fulgens : Green Abalone.
Haliotis gigantea : Giant Abalone.
Haliotis glabra : Glistening Abalone.
Haliotis hargravesi : Hargraves’s Abalone.
Haliotis howensis : Lord Howe Abalone.
Haliotis iris : Blackfoot Abalone.
Haliotis iris : Rainbow Abalone, Paua Abalone.
Haliotis jacnensis : Jacna Abalone.
Haliotis kamschatkana : Pinto Abalone.
Haliotis laevigata smooth : Australian Abalone, Greenlip Abalone.
Haliotis melculus : Honey Abalone.
Haliotis midae : Midas Ear Abalone, Perlemoen Abalone.
Haliotis multiperforata : Many-holed Abalone.
Haliotis ovina : Oval Abalone, Sheep's Ear Abalone
Haliotis parva : Canaliculate Abalone.
Haliotis planata : Planate Abalone.
Haliotis pourtalesii : Pourtale’s Abalone.
Haliotis pulcherrima : Most Beautiful Abalone.
Haliotis queketti : Quekett’s Abalone.
Haliotis roei : Roe's Abalone
Haliotis rosacea: Rosy Abalone.
Haliotis rubra : Ruber Abalone.
Haliotis rufescens: Red Abalone.
Haliotis scalaris : Staircase Abalone, Ridged Ear Abalone.
Haliotis semiplicata : Semiplicate Abalone.
Haliotis sorenseni : White Abalone.
Haliotis spadicea : Blood-spotted Abalone.
Haliotis speciosa : Splendid Abalone.
Haliotis squamata : Scaly Australian Abalone.
Haliotis squamosa : Squamose Abalone.
Haliotis tuberculata : European Edible Abalone, Tube Abalone, Tuberculate Ormer.
Haliotis varia : Variable Abalone.
Haliotis venusta : Lovely Abalone.
Haliotis virginea : Virgin Abalone.
Haliotis walallensis : Northern Green Abalone, Flat Abalone.

Other species : Haliotis clathrata, Haliotis barbouri, Haliotis crebrisculpta, Haliotis dissona, Haliotis exigua, Haliotis fatui, Haliotis kamtschatkana assimilis, Haliotis kamtschatkana kamtschatkana, Haliotis madaka, Haliotis mariae, Haliotis patamakanthini, Haliotis pustulata, Haliotis roberti, Haliotis rubiginosa, Haliotis rubra, Haliotis rugosa, Haliotis thailandis, Haliotis unilateralis.

[edit] References

^ Lin, A., Meyers, M.A. (2005). "Growth and structure in abalone shell". Materials Science and Engineering A 390 (Jan. 15): 27-41. Retrieved on [[2006-05-31]].

[edit] Research

[edit] External links

Categories: Gastropods | Chinese cuisine | Edible molluscs