''Patella aspera'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

limpet Limpets are a group of aquatic snails that exhibit a conical shell shape (patelliform) and a strong, muscular foot. Limpets are members of the class Gastropoda, but are polyphyletic, meaning the various groups called "limpets" descended indep ...

, a type of

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

in the family

Patellidae Patellidae is a taxonomic family of sea snails or true limpets, marine gastropod molluscs in the clade Patellogastropoda. (The superfamily Patelloidea should not be confused with the similar-sounding genus of true limpets ''Patelloida'' which ...

. Long considered to be a subspecies of '' Patella ulyssiponensis'', genetic evidence supports its recognition as a separate species.Weber, L. I., and S. J. Hawkins. (2005)
''Patella aspera'' and ''P. ulyssiponensis'': genetic evidence of speciation in the North-east Atlantic.
''Marine Biology'' 147(1) 153–162. It is native to

Macaronesia Macaronesia (Portuguese: ''Macaronésia,'' Spanish: ''Macaronesia'') is a collection of four volcanic archipelagos in the North Atlantic, off the coasts of Africa and Europe. Each archipelago is made up of a number of List of islands in the At ...

. It is known by the common name Azorean limpet, and its local name is ''lapa brava''.Background document for Azorean limpet, ''Patella aspera''.
OSPAR Convention Biodiversity Series 2010.

Description

''Patella aspera'' has a pentagonal, flattened shell with deeply indented margins. It is sculpted with numerous, semi-regular furrows that radiate from the apex, which is slightly forward of the central point. The exterior of the shell is light brown and the interior is white to bluish-white, delimited by a brown band. The mantle is edged with translucent tentacles and the foot is yellow or orange. This limpet has a maximum length of about and a lifespan of eight years for females and nine years for males.

Distribution

''Patella aspera'' is native to the eastern Atlantic Ocean. It is common in the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

and the coast of Portugal. Its most northerly limit is northern Scotland, and its easternmost limit is the

Isle of Wight The Isle of Wight ( ) is a county in the English Channel, off the coast of Hampshire, from which it is separated by the Solent. It is the largest and second-most populous island of England. Referred to as 'The Island' by residents, the Isle of ...

. It occurs on rocks and in rock pools in the

littoral zone The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal areas ...

Ecology

This species lives on rocks in the shallow sublittoral and

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...

s. It is a

keystone species A keystone species is a species which has a disproportionately large effect on its natural environment relative to its abundance, a concept introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaini ...

which is of ecological importance as a grazer. Breeding takes place all year round, with a peak of activity in the winter, from January to April. It is collected for food.

Overharvesting Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term app ...

is the main threat to the species, which has faced population declines and collapse of its fishery. Harvest has been banned in some areas. Overharvest is particularly damaging to the species because larger individuals are targeted, and these are more likely to be female. The species is protandric, with individuals being born male and often becoming female with age. The loss of the individuals that grow large enough to turn female leaves the population without enough breeding females.Faria, J., et al. (2015)
A new multiplexed microsatellite tool for metapopulation studies in the overexploited endemic limpet ''Patella aspera'' (Röding, 1798).
''Animal Genetics'', 46(1), 96–97.

References

External links

''Patella aspera'' Röding, 1798.
''In'': MolluscaBase (2015). Accessed through: World Register of Marine Species. Patellidae Molluscs of Macaronesia Gastropods described in 1798 {{Patellidae-stub