''Jasus frontalis'', known as the Juan Fernández rock lobster, is a species of

spiny lobster Spiny lobsters, also known as langustas, langouste, or rock lobsters, are a family (Palinuridae) of about 60 species of achelate crustaceans, in the Decapoda Reptantia. Spiny lobsters are also, especially in Australia, New Zealand, Ireland, S ...

in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

Jasus ''Jasus'' is a genus of spiny lobsters which live in the oceans of the Southern Hemisphere. They have two distinct " horns" projecting from the front of the carapace, but lack the stridulating organs present in almost all other genera of spi ...

'', found around the Juan Fernández and Desventuradas Islands in the south-eastern

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five 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 the contine ...

Description and life cycle

Male adults of ''Jasus frontalis'' reach a maximum length of (

carapace A carapace is a dorsal (upper) 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 und ...

length ), with females slightly smaller at long (carapace length ). Females reach

sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definit ...

after around seven years, when they have reached a carapace length of . ''Jasus frontalis'' differs from the other two species in its

species group In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

– ''

Jasus tristani ''Jasus paulensis'', also commonly known as the St Paul rock lobster, is a species of spiny lobster found in the waters around Saint Paul Island in the southern Indian Ocean and around Tristan da Cunha in the southern Atlantic Ocean. At one t ...

'' and ''

Jasus paulensis ''Jasus paulensis'', also commonly known as the St Paul rock lobster, is a species of spiny lobster found in the waters around Saint Paul Island in the southern Indian Ocean and around Tristan da Cunha in the southern Atlantic Ocean. At one t ...

'' – by the lack of sculpturation on the first abdominal somite.

Distribution and fishery

''Jasus frontalis'' lives in the seas around the

Juan Fernández Islands The Juan Fernández Islands ( es, Archipiélago Juan Fernández) are a sparsely inhabited series of islands in the South Pacific Ocean reliant on tourism and fishing. Situated off the coast of Chile, they are composed of three main volcanic i ...

and the Desventuradas Islands, off the coast of

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...

, at depths of , where the water is at a temperature of . The species was found to be plentiful and easily caught by early explorers who visited the area, such as Jacob Roggeveen (in 1722) and George Anson (in 1741). Today, ''J. frontalis'' is commercially fished throughout its range. The

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

states that while the catch has reportedly diminished and fishing efforts have increased, there is little quantifiable data on the catch per unit effort for estimating the conservation status and outlook for the species.

References

{{Taxonbar, from=Q377423 Achelata Crustaceans of the eastern Pacific Ocean Invertebrates of Chile Edible crustaceans Commercial crustaceans Crustaceans described in 1837 Taxa named by Henri Milne-Edwards