Western rock lobster
Encyclopedia
Panulirus cygnus is a species of spiny lobster
Spiny lobster
Spiny lobsters, also known as langouste or rock lobsters, are a family of about 45 species of achelate crustaceans, in the Decapoda Reptantia...

 (family Palinuridae), found off the west coast of 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...

. Panulirus cygnus is the basis of Australia's most valuable fishery
Fishery
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...

, making up 20% of value of Australia's total fishing industry
Fishing industry
The fishing industry includes any industry or activity concerned with taking, culturing, processing, preserving, storing, transporting, marketing or selling fish or fish products....

, and is identified as the western rock lobster.

Description

The species has five pairs of legs that are used to move across the ocean floor, the fifth set possessing claws in the female, and six smaller pairs are located at the mouth. The eyes are located at the ends of stalks. They vary in colour from a brownish purple to a pale colour. The exoskeleton is segmented, and must be shed as the animal grows. The largest recorded specimen is 5.5 kilograms (12.1 lb), but a maximum weight of 5.5 kg (12.1 lb) is considered typical. The average accepted form of measurement, that of the carapace
Carapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...

, is from 80 to 100 mm (3.1 to 3.9 ) in length.

Distribution

The range of the species is along the 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...

, from Hamelin Bay to the North West Cape
North West Cape
North West Cape is a large peninsula of land in the north west coast of Western Australia. Cape Range runs down the spine of the peninsula and Ningaloo Reef runs along the western edge...

, and at islands such as the Houtman Abrolhos
Houtman Abrolhos
The Houtman Abrolhos is a chain of 122 islands, and associated coral reefs, in the Indian Ocean off the west coast of Australia. Nominally located at , it lies about eighty kilometres west of Geraldton, Western Australia...

. The larvae of the species develop in the meadows of seagrasses of Western Australia
Seagrasses of Western Australia
The Seagrasses of Western Australia are submerged flowering plants found along the coast, around islands, and in estuaries of Western Australia. The region contains some of the largest seagrass meadows in the world, and is the most diverse in the number of species...

, migrating out from these toward the deeper ocean and coral reefs such as the Abrolhos Islands.

Fisheries

The annual catch is 8,000–15,000 ton
Ton
The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight, and as a unit of volume. It can also be used as a measure of energy, for truck classification, or as a colloquial term.It is derived from...

s. The value of production in 2003/2004 was A$
Australian dollar
The Australian dollar is the currency of the Commonwealth of Australia, including Christmas Island, Cocos Islands, and Norfolk Island, as well as the independent Pacific Island states of Kiribati, Nauru and Tuvalu...

248 million. The fishery was one of the first in the world to be certified as ecologically sustainable by the Marine Stewardship Council
Marine Stewardship Council
The Marine Stewardship Council is an independent non-profit organization with an ecolabel and fishery certification programme. Fisheries that are assessed and meet the standard can use the MSC blue ecolabel. The MSC mission is to 'reward sustainable fishing practices’...

. The western coastline contains eight species of rock lobster
Spiny lobster
Spiny lobsters, also known as langouste or rock lobsters, are a family of about 45 species of achelate crustaceans, in the Decapoda Reptantia...

, but the harvest primarily targets Panulirus cygnus.

The species is known to have been caught since the settlement of Swan River Colony
Swan River Colony
The Swan River Colony was a British settlement established in 1829 on the Swan River, in Western Australia. The name was a pars pro toto for Western Australia. In 1832, the colony was officially renamed Western Australia, when the colony's founding Lieutenant-Governor, Captain James Stirling,...

, in 1829, and expanded as the larger populations were discovered in remote locations of the state. The industry came to be centred at the Houtman Abrolhos, at the edge of the continental shelf, where the mature crays occur in large populations. A cannery was established at the islands to export the seasonal catch in the 1930s. The early industry claimed to harvest up to fourteen species, however, research into the Abrolhos populations recognised only three.

The population harvested near Dongara is reputed to be a greater delicacy amongst consumers, although investigation of that catch did not reveal any morphological distinctions from other populations.

Taxonomic history

Panulirus cygnus was previously classified under several taxonomic arrangements, the first description was published in 1962. The author, Ray George, recognised the similarities to other species of Panulirus
Panulirus
Panulirus is a genus of spiny lobsters in the family Palinuridae, including those species which have long flagella on their first antennae. It contains the following species:* Panulirus argus — Caribbean spiny lobster...

, such as Panulirus longipes, but regarded the number of distinctions qualified this as a separate species. The generic name is an anagram of Palinurus
Palinurus (genus)
Palinurus is a genus of spiny lobsters in the family Palinuridae. A 110 million-year old fossil, recognisable as a member of the genus Palinurus, was discovered in a quarry in El Espinal in Mexico's Chiapas state in 1995 and named P...

, as with other genera of its nominal family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Palinuridae, the spiny lobsters. The name is derived from Palinurus
Palinurus
Palinurus, in Roman mythology, is the helmsman of a ship of the Trojan hero Aeneas, whose descendants would one day found the city of Rome. As the price for the safe passage of Aeneas and his people from Sicily to Italy, Palinurus loses his life, one on behalf of many Palinurus, in Roman mythology,...

, mentioned in the Aeneid
Aeneid
The Aeneid is a Latin epic poem, written by Virgil between 29 and 19 BC, that tells the legendary story of Aeneas, a Trojan who travelled to Italy, where he became the ancestor of the Romans. It is composed of roughly 10,000 lines in dactylic hexameter...

, whose improper burial caused his soul to drift near the coast to the open seas; an appropriate metaphor for the habits of the spiny lobsters that develop near the coast and migrate away from it.

The specific epithet is named for an emblem 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...

, Cygnus atratus, the Black Swan
Black Swan
The Black Swan is a large waterbird, a species of swan, which breeds mainly in the southeast and southwest regions of Australia. The species was hunted to extinction in New Zealand, but later reintroduced. Within Australia they are nomadic, with erratic migration patterns dependent upon climatic...

. The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

 was collected by George in a pool at Rottnest, at a depth of 1 metre, and preserved at the state's museum (WAM); other specimens in their collection were reclassified as paratype
Paratype
Paratype is a technical term used in the scientific naming of species and other taxa of organisms. The exact meaning of the term paratype when it is used in zoology is not the same as the meaning when it is used in botany...

s. George's taxon was demoted to a subspecies until the 1970s, when a revision recognised the population as a species. The recognition of the species was relevant to the conservation of its related fishing industry, it is unique to the region and could not be naturally repopulated from other regions.

Common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

s of the species include "western rock lobster", "Australian spiny lobster", or locally as the "western crayfish". The common names of "lobster", "homard" and "yabbie" are also used to refer to this species, along with many other crustaceans.
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